New ES250 Trophy Project!

[Blurredman]

Ah the dishwasher is great!



Well last night I had it all back together. But before I get to that. The picture of the new bolt in it's place (as you can see I have filed away some of the protruding surface). Yes I did install two copper washers to counter the fact the thread of
the bolt didn't go all the way to the head, but I didn't really want to drill a recess in the tapped hole.. I did indeed put some RTV on the thread too.

The clutch is back together. Notice this- something that isn't mentioned (at least to my knowledge) about the ETZ models. Presumably balancing was able to be done alot more accurately later on, but the 'D' in this case (the manual states 'X', but I guess it could be anything the builder had), need to be aligned like so. (page 35 of the official service manual). The slave to the pressure plate doesn't have such a marking however so that can be wherever it seems.

I did take measurement of the plates and springs before assembly (the longer springs being most opposit eachother as possible).
The spring measurements according to the book are supposed to be 28.3 - or + 0.6mm. Mine were: 26.6, 27, 26.8, 26.6, 26.8 and 26.6. A bit compressed over time but I find that all the springs I have dealt with on these clutch are. Will have to just keep an eye on the clutch engagement and feel for slip at speed etc. I already have a somewhat ongoing problem with my 251 regarding clutch slip because of shorter(!) aftermarket springs. My etz250 had slip too, but I decided to replace with original 2nd hand springs (pre-used) and that has no slip despite them being short too.

Anyway: Friction plate is supposed to be 3.0 - or + 0.1mm when new, and a wear value of - 0.3mm. Mine are as follows: 2.85, 2.8, 2.75, 2.8, 2.8.
Steel plates (have lovely cross hatching on them still!) are 1.5mm - or + 0.1mm, and mine were 1.6, 1.5, 1.6, 1.45.

So at least I have those documented. The condition of them were very good, with just minor scoring on one or two of the friction plates. But, we will have to just see how the bike goes as it is and we'll cross that bridge later if any of these components are an issue. The fact of the matter is this bike is not going to see the 24/7 use say my etz251 gets. Therefore, these components all together could last me another 10 years. In the spirit of keeping the renovation cheap enough to make the bike usable, but not a restoration (at this point), this is fine by me.


And... I lubbed the thrust bearing and installed it too.

Installed the clutch (lubbed the pinion bearing again), and installed the clutch cover back on after a thorough cleaning of metal debree. Immediately I tightened it up just enough to feel what that clutch would be like- and it was the same as before! Extremely difficult to pull in..! However I did notice that the outter sheeth of the new clutch cable had become compressed slightly at the point where it enters the clutch cover. I put the original cable that the bike had, back on the bike and it was completely different. Sure it's a heavier clutch than the later bikes, but it was now smooth, groan free, and as light as it should be (I imagine). Interesting.

[Blurredman]

And here we have the bike assembled (container for catching over fill from topping up transmission). I used new copper rings for all bolts that required them. I haven't however put a cotter pin on the end of the crank bolt. Though that's easy enough to do that at a later date.

The bike started readily enough and I let it run for a while to try and tune it a little but it's still a little unreliable on the idle front. It might be the case that is similar to my 251. Idle speed in neutral after first starting is around 1700. With clutch in, 1300. But if been riding, then slowing down it can idle for a while at the 15/1600 mark and then gradually (but reliably) sink back down to the set ideal speed of 1300. Without a tacho it's a little difficult to determine what this ES250 is doing. And my RPM calculating strobe light is broken so....

Alas, Saturday I hope to do an errand or two, so other than perhaps a quick whizz around the local estate tonight maybe, Saturday will be it's 2nd shakedown and maiden voyage. As said- the clutch is working lovely in operation. Smooth and ungrumbly and doesn't rattle.. One thing not evident in the video (and yes, I admit I gave it little thought for already previously mentioned reasons), is that cylinder certainly sounds rattly within that bore! Ahh I suppose that means less liklihood of seizing I suppose..

[Puffs]

I have no doubt the dishwasher works great, but I anticipate marital problems if I'd use it. And also, personally I think it's a bit off to put things with sulphur-doped oils on them in the same place as the dishes I'll eat off tonight; I'll just use a brush with diesel or paraffin to clean engine parts.

That plug should work, and yes, that makes sense. The advantage of having the clutch on the crankshaft is that the torque forces are much lower, but a disadvantage is that it must be balanced. And remain balanced, also with use.

So it required a different cable... Odd. But good you found it.

Enjoy your soon-to-come ride with the bike!

[Blurredman]

Okay.. To-day, despite the awful wind, and the coldness, I did a 55 mile round trip to do some of my errands.

A few things to point out:

- The speedo needle started being even more wavery than usual, and the mile counter has stopped turning. It also buzzes a bit. I disconnected it when I realised though so hopefully possible internal gear damage won't be too excessive. Will have to be careful pulling back the metal crimped assembly. I can see there is corrosion in there somewhere anyway as some of the number cylinders have what appears to be rust on the numbers.

- Although the bike went well (it sat nicely at one point at 50 lovely!), I did then check the spark plug condition and the main needle position. It was on the 2nd richest, but the spark plug maybe (??) looked a bit lean at the time (though that's hard to determine because I didn't do a 'plug chop' at that point). So I richened it out again. However, i'm not sure if it's too rich because when pulling the throttle in a higher gear, at a certain point in the throttle travel the bike will kind of misfire... It didn't do that before I richened it. Anyway- I did a bit of a plug chop on the way home. The picture isn't very good, and actually it's darker in real life, but here we are:

- Thirdly, after a while of using it, I realised why the idle was so... up and down a bit, but also that the bike still continued to rev with the clutch pulled in (to change gear). After realising this, I learnt to push the throttle tube anti-clockwise.. It seems there is a bit of tension maybe pulling on the handlebar slide... But I don't know, because there's a spring there which is meant to counter against the cable being too slack with the slide (?). Odd. I'll have to obviously look into that. I haven't actually lubbed any of the cables, so it might be beneficial for me to do that foremost.

- The brakes are actually pretty good I think. I do have to do some adjustment on the rear though- that pedal travels far far to far. This was partly down to the footrest being bent upwards a bit- but I bent that more paralell to the ground so it's not too much of an issue anymore. Feels like I just need to move the torque pivot arm on the rear drum anti-clockwise a bit in order to be able to screw some more pre-load into the brake system.

- The clutch.. It is heavy! But it's working nicely. Esspecially after nice adjustment. But, I notice this, and i'm not sure if it's because of the strange length of the cable (and something therefore catching it I would think), is when the bars are turned left, the clutch adjustment (the cable is snagged slightly in the front wheel forks) dissapears and then suddenly you have it- basically the ability to slip has gone. And with that too is that turning the bars right, the throttle raises. That could be choke or throttle. Like I said, these cables need lubrication for a start. But, ideally a shorter clutch cable would suit better. The less kinks in the cables the smoother they are and less likely to hang up (not to mention they are also typically lighter because of less curves).

- The bike performed really well in all - absolutely no dramas and it covered the mileage well, and I can't believe how many people were looking at the thing. One thing I will have to get used to is those gears! 3rd is fine @ 30mph, but the whole ratio design is completely different to the 5 speeds, obviously. But.. the 'space' between gears I did find a few times, and what with the engine speed being raised too high when changing gear, gear crunches are of course apparent. Best to get up to higher speed, then wait a long time with the clutch in and throttle tubed pushed back clockwise and then change gear. Anyway, even at this point the gearbox is certainly something you have to do decidedly, well timed and not indiscriminately.

- The brake light still fades at idle sort of speed. Interesting. Will have to keep my eye on that maybe.

Current plans?
I'm going to:
- Take all the cables off and lubricate them
- Take note of measurements of the throttle handlebar slide and how it works properly
- Now is a good time to take wheels off and clean out those brake drums from the rust dust now that they've worn in a bit.
- Adjust the rear brake afterwards.
- Recondition the speedometer.

The tyres felt okay (for cheapies) and the handling of the bike was very nice I have to say! Engine is torquey and linear. Lovely.

Nothing else comes to my mind at the minute- I don't think anyway. Will edit this post if I do.. Now is time for a very hot bath.


EDIT: Had a brain thought. The airbox cover does have some holes in it (they are factory however, and indeed not even mentioned in the manual. I might look into those, as well as the huge o-ring that goes around it.

[Puffs]

Very Good! After 55 miles you should have a reasonable impression of the bike.

Speedo: would spraying WD40 inside help? Watch out not to soil the glass on the inside!

Jetting: yes that seems a bit lean. But if you richened it, by positioning the needle in the highest slot, and it began to misfire in the mid range of the throttle, the needle should probably come down again.

For reference, sections from the YZ250 manual I posted earlier; I find these quite useful. But note: it pertains to a quite different carb (a Mikuni TM38SS), so not everything is completely applicable you your case. And also, the plug pics (originally in black & white) are very dark. Nevertheless, a good indication of where the different jets are active.

I prefer to start with the main jet, but in your case, with a newly rebuilt engine that was designed for different fuels & oils, that is a bit of a leap. But maybe after 55 miles it would be time for a proper plug chop. And while the modern fuel (E10?) has changed, I would expect not to stray too far from the factory prescription. And also, those holes in the airbox you mention, do they cause the flow to bypass the filter (partly)? The factory jetting specs expect a non-leaking path to a clean & standard air filter and a standard suction tract; any differences may need adaptations to the jetting (and a 2T needs good filtering).
But also it's quite cold now, which means there's more weight of O2 per air volume. Air shrinks when it cools; a leaning effect.

Throttle cables like being lubed with a thin PTFE oil as used for chains & dérailleurs on bicycles, or just 10W40. For a more manly clutch cable I tend to use something thicker, like motorcycle chain lube. The clutch on the standard 250cc ETZs is uncommonly light, and maybe the ES was just supposed to be closer to the norm.

If it's anything like my 4-speed Jawa, you have to shift gears in a sedate but decisive manner. Those 5-speed ETZ boxes are clearly more modern & better. Obviously the 4 gears are wider apart, ratio-wise, but I suspect the engine's torque curve is also broader.

Next week it will be warmer again and maybe the salt will wash away.

[Blurredman]

Definitely. 55 miles is a fair amount for a bike I had only gone to the petrol station and back (and around the block once or twice). I was half expecting perhaps problems with the coil breaking down, or the ignition resistor potentially being a problem. But in that aspect, it was realiable!


Speedo: I don't know. I think i'm more inclined to take the thing apart - I haven't taken an MZ speedo apart before actually, but they're all the same. It has worked for a total of 10 miles, and then stopped. I think it needs some checking out. I rely on the speedometer mainly for the mileage cylinders, because I'm quite excessive (perhaps) about recording mileage, but also I like to 'just know' how far I have travelled, and of course maintenance records!

The holes in the airbox (they are factory, but as I said the manual states nothing about them), do bypass the filter. They're only small (I suppose with RTV or rubber washers I can thread in some M8 bolts- but I have an abundance of imperial nuts and bolts so they may have to do). Regardles, it doesn't make sense to have holes in the airbox, maybe someone with an ES on this forum can advise? You can see the holes in the cover in figure 117 of the official manual, page 49. The two lowermost on the cover itself. My model doesn't come with a filter retention bracket either, however, it does have a spring on the cover that keeps the filter in position on the induction hole- I suppose that might have been a design change for in production. (figure 120, page 50).


With the jet needle in the richest position it certainly makes the bike torque-ier and nice to ride in country lanes, but it's not right. I've mentioned this before and i'll mention it again- the tip of the needle is broken slightly anyway so it may artificially be running richer anyway, and yes when pulling back the throttle (uphill mostly) it would bog and misfire. But then, if there is an air leak, that should counter the needle position. All things that need to be addressed- and yes, 95 E10 fuel has been used. And actually, that plug picture is a 'plug chop'.


Thanks for the diagrammes, they do help- esspecially the fuel jet overlap/working territory.



I've lubbed all my cables the same in the past, and actually I have already taken them all off (except the speedo cable, which although new (and I will still do it) I think it will be easier to do that in situ. Most of the cables have either a bit of rubbing on the outter sheeth or indeed have a split outer sheeth (perpendicular). That isn't too much of a problem normally, but it depends on what it operates. The throttle cable does have a break at one point in the outter sheeth so there could be compression issues in regards to the cable taughtness. All cables do have all the inner cable strands however.

Most of them off the bike are indeed not the smoothest, the clutch cable is the best. But the front brake cable is very stiff indeed. Interesting because that was a good brake and the cable seemed to be working as it should- that would however be down to the strong spring evident on the shoes to push the cam back into neutral position.

Nevertheless, I am gong to be lubricating them all with a view to hopefully rejuvinating them, for as long as I am able to anyway- I went 4 or 5 years on my etz251 with broken sheethed and notchy cables, all with the help of just some lubrication once or twice (and then they broke after a long worn trooper service). Though that bike (etz251) only has the speedo and choke cables intact now (the rotational force of a speedo cable is not as strong as a pull/push action), and the choke cable doesn't even really get used but once or twice a day so esspecially the choke cable lasts an awful long time.


Anyway- a picture of the throttle cable in my favourite (read cheapest) position for lubrication process (I use 2t oil as that's the most disposable, and has worked fine many many times previously) - sometimes this can take 30 minutes, sometimes hours. Depends on the cable quality (dirt etc inside) and whether you push/pull the cable occasionally. I did actually temporarily fit up the replacement clutch cable that I was given (for a TS250 High bar model) and actually that does fit- though actually i'd say it's a bit short maybe for the bars turning left. It's a reproduction cable made in the 80's from a British cable maker in Chester - came in a box and everything. Either way, both cables being either side of perfect I think it's best to just keep the one I don't decide to use on the bike as a spare, as indeed I should do with all the cables- except only a couple I have (mainly for other MZ's) I think are viable. Before fitting all the cables together on the bike after lubrication, I will test fit the alternative cables. Maybe they will fit after all.
I'll be heatshrinking the minor sheeth damages but some parts of some cables look burnt (but could just be internal rust coming through). The worst as mentioned is actually the throttle cable so I will try and rig up the possibility of heatshrinking over some straight lengths (for example nails without the heads) in order to support the sheath better and prevent distortion both in the pull/push factor but also twisting.

Since my bike doesn't have indicators, I also might find it helpful (esspecially for cable snag/routing issues) to remove the RHS switchgear. This is the switch for the indicators. Removal of this might free up space on the cable entrance to the front headlamp and through the length of the bike, with less 'useless' wires being in the way. Coming back to the clutch cable, if the replacement one turns out to just be too short, then I suppose it's possible I could route the longer one around through the cable entrance on the other side of the headstock (where the brake/throttle/choke cable go through), and loop it back around. That may just reduce the excess length a little bit to provide a good clutch operation on full left and full right lock.

As for the front drum (when removing the cable), the lining is free from rust - just a little pitted, but as previously assumed (and I have done in the past anyway so I know) just using the brakes is the easiest and quickest way to get rid of drum lining surface rust. I have yet to touch the rear wheel however.

[Puffs]

Mileage for maintenance: things like chain & points (or in fact: most) you do as required, and for the rest you record the fuel you use. As you know roughly how much it uses, it's an indication of the distance done. Taking a speedo apart is not easy, I think.

Does the current behaviour of its mileometer cast doubts on the mileage the bike has done? Not that it matters, obviously.

Ah, the dry micronic type! Who would have expected the old bike to have so many words in his manual.
The slightly better pic from Miraculis:

ES 250_2, Fig 117.GIF (14.77 KiB) Viewed 19454 times

I guess the filter 7 goes on top of that hole in the air box, which they call casing, pushed down by 9, and that the carb attaches to 6 & draws a vacuum in the air box. There shouldn't be any holes in that box. The manual also says "Before assembling, carefully clean casing and cover and check them for cracks and damage (air leaks)." I don't know what those 'holes' in the cover are for, anything to do with 2 & 3?

Maybe get a new needle? If it misses the tip...

I'm sure you'll sort those cables out fine!

Be careful with that brake dust; on these old shoes they may still have used asbestos.

[Blurredman]

I'll have to take a picture of said holes for you. There are a few (very hard) bung things that were the remaining little bits and pieces that came with the bike that I wasn't sure where would go (although those holes didalways intruige me). Anyway, I think they must be there for moulding maybe as this is bakelite stuff, or perhaps to remove vibration noise (but then why not some at the top?). Bolts 2 and 3 go through springs and keep the other bakelite piece (that the electrics/coil etc mount onto) in place on the frame- the air box and the electrical mounting piece just squeeze around the frame. They don't bolt directly on the frame themselves- not sure why. Vibrations ? oh well.

The ES250 speedo will be easier to pry on the crimped over metal than a circular clock because of the two corners- there may be much easier wiggle room to get that crimp up. I've actually been told that the internals are the same as the TS model anyway, and I do have one of those spare- so if it's the case of broken or worn through (plastic cogs wearing away because of lack of lubrication) then it shouldn't be too much of an issue to use some spare parts from my spare clock. The speedo needle did wobble about a bit after initial operation - but the mileage clock always seemed timely and reliable. So we'll see what's what later on when I work on that. I suppose it might be best though to check the TS speedo actually works however, hehe.

I've looked for needles, and the main jet assembly- they're impossible to find, at least in this county. You can find them abroad but expensive (plus costs of import) at this point in time, ES's are not so common anymore.. So will just to see how my progress goes with relation to air leaks- the thing is, those holes might be small, sure- and of course I suppose they don't give too much of an impact at a higher cruising speed or high throttle (in terms of ratio), but- it could certainly explain why the idle might be high after closing the throttle. One thing at a time I suppose.

Yes the front brake did smell a bit funny, but I think that was just the smell of rust dust - a bit like an electric motors warm carbon brushes.

[Puffs]

Pics: if you get to it, but it shouldn't leak air before the filter, I'd guess.
But don't expect too much difference in jetting due to some relatively small holes. Well, for sucking in dust it can make a major difference.

Speedo: give it a try then! Wiggling may be due to the cable.

We'll take the needle offline.

[Blurredman]

Well guy(s), I'm a bit closer. All the cables were lubricated up some nights ago and cleaned and lubricated the throttle assembly and I took the speedometer apart. It was tough, to turn those gears over by hand (on my poor fingers too), but every now and then seemed to get stuck on the last click of the gear that changes the number drum up one mile. There does appear to be some wear on the lower brass gear caused by the worm gear too because of this inability to turn over, and to just lock.




I lubricated as much as I could without getting messy- it wasn't bad in there at all- but you can see some red rust form over the main bar that holds the plastic cogs that actually clock the mileage.



I picked up some 19mm scratch resistor feet that you put on the bottom of legs of furniture from a hardware store, and I put one (three in total) over each of the holes in the airbox that are intended for rubber anti-vibration mounts (for the main metal cover). Circled in Red on the airbox cover are the three pertinent holes.




I put the main needle to 4th position (from the top), so leaner than in the previous picture. And here is the result after a 'plug chop'. As you can see, much much healthier. Just compare it to the previous plug pictures in this thread.. The first one is without flash, the 2nd one is with flash. Using the flash obviously makes it look leaner a little.





After doing this, I re-attached my lubricated speedometer which I was happy might be working okay, and the cable. And attempted to ride to a hardware store for some brake cleaner (to check for any more air leaks, less obvious ones). But I was running short on time, so I only went on a 15 mile ride. Moreover the wind over the mountain roads was just not a nice experience for actual testing so I did indeed cut it short and didn't get the brake cleaner. I did however manage to get an acceptablish idle and low throttle power delivery by having the richness screw turned to 2.5 turns out, right in the middle of the "2 to 3 turns" the book states. Unfortunately, on this ride, although the speedo worked initially for 4 miles.. it stopped recording mileage and the needle wavered all over the place again. Not sure whether I should turn the extra 27 miles I later did by hand and work it in a bit first (I think i'll do that first), but I think soon it might be the case where I have to take it apart fully and either lubricate and clean whatever is causing the issue (the 1 mile cog not slipping into position with the main driven cog), or replace the unit with spares from a TS clock that I have around.


Oh well- later on that night I had time and my brother came over and he was desperate for a ride so we took some pictures of the bike too..
One annoyance was realising the new speedo cable was touching (and thus melted a bit) on the exhaust downpipe! Gahhh!





The idle is still a bit weird. It's hard not to push the throttle forwards for example when using the front brake, and at idle in traffic you do have to keep a little bit on that throttle to stop it defaulting to naturally going forwards and getting what I can only think is a rich idle (I suppose the throttle slide is closing significantly when this happens). So.. it's still a bit of a game to try and find an idle that would work, which doesn't seem to high, and fighting the fact that the bike might want to die.

I think, design process wise the feature is not only there in looks and sleekness, but also because pushing the throttle forward fully against the small spring in the handlebar, closes the throttle slide to air and brings the idle down a lot quicker and thus you can change gears without too much gear clunk noise or indeed missing them all together- design? I don't know, but it works at achieving these things.
Perhaps this is where the long held myth that "mz's don't idle" came from.

[Blurredman]

Last night I did a few things.

Namely: I took apart the speedo again. I clocked up the mileage to what it should be, but then cycled 20 miles up, then 40 miles back down (just turn the cog in reverse direction there is no stop), then 20 miles back up to the proper mileage covered thus far.

This time the more I 'massaged' the driven gear the easier it got to turn, though only slightly. However one thing of note is that this exercise up and down the miles has shown me that the 1 mile unit drum doesn't seem to be getting caught up anymore with the gears that keep the drums aligned. I didn't have to intervene - I just span the main brass driven gear. This is hopeful. The clock is back on the bike and I hope this exercise will be it's last, although unlike before I do think perhaps I can do this once more before getting frustrated and taking the internals of my other spare clock. The lower brass gear has been worn a little bit more by the worm gear- but hopefully that won't affect operation. Will see how this goes. If it makes 100 miles or so without problems, I will bend down the glass and moisture retaining ring and call it a day here..


The indicator switch and the wiring associated and (yamaha replacement relay) with it has been removed from the bike- At this point there's no point this stuff being here without indicators on the bike (at this stage-if they will be fitted at all). It frees up a bit of space in the headlamp unit and prevents the cables and wires fighting for space in the cable entry below the handlebars - this should help the throttle/brake/choke cables run nicely and without snagging. What's more, in the future if I decide to for any reason, I suppose I have a spare switch that I could use for other purposes.


I removed the rear wheel. Cleaned out the dust in the drum and also adjusted the brake pivot arm in the shoe assembly to remove the slack in the brake application. After doing this I also had to adjust the brake light switch. The rear drum lining hasn't cleared of rust totally fully yet, but it's half way there.

I also decided to lightly sand the points in the voltage regulator. It seems evident that it is not as strong to charge the battery with the lights on. I have yet to clarify however whether this has done anything, with my multimeter.


One thing I had an idea about was the throttle. It came to me in the book that there is a purpose to being able to push the throttle forward - to close the slide on the carburettor and prevent the surging that can happen on over-run which people complain about. This is a safety feature too I think really, as it can aid smooth deceleration and smooth riding in wintery conditions. The features of this bike for the purpose of being helpful and user friendly really are ingenious I think. It shows that this is a bike made for a commuter and all weather rider who doesn't have a car.
So on this, I had a theory. The spring in the throttle has been uncompressed since '82/83, but the carburettor slide spring has been compressed in the carburettor since that period. Perhaps it's strength has gone and doesn't push the throttle slide forcefully enough. It had a length of 53mm, and I subsequently stretched it slightly to about 61mm. Fitted to the bike, I can actually now tell a difference that the idle after a rev does go down quicker and stay in the set idle position, as opposed to doing so but then, going further. I have yet to actually test ride the bike so unsure how well this 'fix' has gone, but I suppose I can stretch the spring a little bit more if needed, or indeed buy a replacement. But.. promising progress! If indeed.... anyone is reading these updates???????

[dave47]

Yes, i am reading them with great interest. You are doing a great job. The needles and jets are listed at THEMZSHOP, as is the seal for the ETZ brake.

[Blurredman]

Thanks Dave47. It's nice to know people are still enjoying!

Regarding the ETZ brake master cylinder seals, I bought some (I always buy these things in pairs just for future's sake) a month or two back, but only just last night did I fit one (yes including the outter seal... what did I say about pairs...?! ) and I am glad to say that the ETZ250 brake is now fixed there!

[Blurredman]

I eventually had time to ride the bike to the hardware store to get some more carburettor cleaner.

The facts are these: The day wasn't the nicest but it was at least sunday so less road users- still, I had to go over moor ground over the hills so it was windy (of course), raining and foggy. Slow progress. I did change the main needle half way into my ride to the third notch, and although less torque down low it seemed happy enough.

I did look at the spring in the carburettor again and find that it had squashed back down to pretty much the original spring length. However that isn't a great surprise. There must be a spring length/strength stated somewhere!? At least to stop me from potentially overthinking and focusing on that spring perhaps..


With the carb cleaner when I got home I traced some more air leaks to the air box. The two through bolts (through the cover and hold on the metal cover) let in air so I used some 1/2" tap washers inside the box. This has made it leak free there. The box itself is now leak free. I'm looking through the ES manual mentions "After putting the cover on the two tie-bolts, slip a foam rubber ring one each bolt." this is I believe in reference between the cover and the metal outter cover - (you can see these potential rubber/foam discs on figure 146 on page 61). To me this I suppose is niether here nor there seeing as I ended up putting the tap washers inside the cover instead. This means that the rubber washers on the thumb nuts don't necessarily need to be in any good condition at all. Additionally, on page 49 there are paragraphs about the airbox which I have read more carefully now. It does mention that there are supposed to be 'sealing discs' between the air box and the 'electrical item carrier'. There is typically a gap of 2mm intended for stress relief, but this must be filled in with 'sealing discs'. Interesting note, the same springs that keep the tension on the clamping bolts are the same pat number as MZ clutch springs... This is something I'll need to look at (gap size and implement 'ring'). But this does answer some more questions. Maybe there is a slight air leak here too. It's a pity these 'foam rubber discs' weren't listed or displayed on the parts diagrammes as it would have been more obvious then. I don't think this is a very good design for an airbox, with it's requirements of additional 'discs' and grommits to prevent air ingress. Certainly the later TS250's and subsequnt bikes have a much more robust airbox.

So I think (other than the airbox to electrical carrier plate through bolts) that the airbox itself is now tight. But I still detect some engine speed rise with the carb cleaner around the carburettor area. I have already re-packed the mouth of the inlet with grease and it seems leak free there. It may be coming from the rubber tube, perhaps it needs tightening up. But also, the book mentions this about possible lean conditions: "e) Cover sealing forced out of its seat due to splashing of carburettor." (page 50). I'm not sure entirely what that means, but it makes me wonder about the carburettor main slide rubber item. Whether this is part of air leak control...

One of these (which I do have but haven't actually fitted...) :



EDIT: I forgot to mention that ever since removing the indicator switch and associated wiring... BOTH the charge light (which acts as the indicator idiot light too) and the neutral light act exactly the same to eachother... Put in neutral: both lights come on.. Out of neutral: both lights turn off, at the same time. They're both wired correctly according to the wiring diagramme. Does the relay/indicator wiring somehow stop this happening? I'm not sure why it would as the neutral light has no connection at all to the charge or indicator dummy light.. The bike has no high beam idiot light so that's also out of the question. Additionally, something new is that they only work at all when the engine is running, which wasn't the case before.

[DAVID THOMPSON]

after reading the text to posts about getting the 2 smokers to run proper.
i remember why i traded a 1966 Yamaha ym1 305cc for a 1965 BMW R69s in 1970
it was one of the best trades i ever made
dave i switched to MZ in 2002 an rt125 and it been a good run on the German bikes