MZ/MuZ Riders

On a different note... I read that the adjustment screw for the pilot jet (or for air-flow mixture??) is often covered by an aluminum plug. Is this the one? I can drill thru this piece, can't I ?

WaiNYC wrote:The choke cable is still bugging me

I have an addition piece of information to add. The choke lever is actually quite tight. Even before I started taking the bike apart, I had noticed that the choke lever could not move all the way. This is not normal, isn't it? Do you think it has anything to do with why the choke cable is stuck inside the carb?

Pix Choke disengaged position.jpg

Pix Choke engaged position.jpg

Additionally, there is a brass object behind the chamber that houses the throttle valve, which seems to lie on the same axis as the brass nut (and choke cable assembly). Do you think it is something I need to push or wiggle to get the choke cable out?

Pix Brass obj inside .jpg

The choke control won't move much if the enrichening plunger is seized in the body, as yours appears to be. The movement you have is slack in the cable. Either soak the whole assembly in Plus Gas or diesel for a day or so, diesel creeps into every nook and cranny - what you see in the last photo is the seized plunger but it may be the rubber "O" ring which is causing it to stick

Pilot jet screw is underneath the left hand carb (arrow). Mine did not have a plug.
The screwdriver is pointing to the screw that holds in the "super secret" filter screen under the float valve. That is designed to clog up and give you fits finding out why the thing runs poorly...
Location pic (don't have one with the float bowl in place...)

The reason the choke won't engage is the plunger is stuck. Spray some penetrating oil down in that hole and let it soak for a few days. Then YANK the damn thing out.

Pulled mine out this morning just to check it was free.As you can see it`s the same material as the carb body on my Mastiff not brass, and lots of surface area for two pieces to corrode together.Perhaps there is a good reason why it was changed from brass.

I am ready to seek an alternative solution to the stuck choke assembly. Following everyone's suggestion here, I socked that part of the carburetor in sea form on Friday morning. It's been 3 full days. It is still stuck.

I will apply some heat tomorrow to see if that loosens it. If that fails, is drilling the corroded and stuck part ([2], in the diagram below) the only remaining option?

Does anyone know the part number for [2]?
I guess if I cannot replace [2], I would use a plunger-style choke instead, as edfmaniac suggested.

Cut the cable up near the handle bars, it's probably toast anyway, slide the outer sleeve off so you just have the inner wire that is still stuck in the carb. Tie it around something with mass, like a barbell, and put the carb in a vice or in the hands of a very strong friend. Get the picture yet? It will come out. If you break the cable trying, it needed to come out anyway so you can drill it.

Heat is your best friend when it comes down to breaking down corrosion combined with edfmaniacs technique. Drilling out really is a last resort, requiring workshop facilities really-Machine vice, milling machine/pedestal drill and centre drill.Drilling into that slot is far from ideal.

Is the suggested replacement a simple on/off device? If so, i would miss the handlebar three position control i have on mine.
Mine is the original 10 year old cable and plunger, regular use and occasional spraying with lubricant spray keeping it working as it should.Perhaps my habit of adding a dash of 2 stroke oil to the fuel helps matters in the carb department as well.

Good luck!

The plunger style choke can be opened to any position you need. It doesn't have preset positions.

Restoring bikes is a constantly frustrating process of two steps forward, one step back, isn't it? Well at least it has been for me

So, I finally got the choke assembly yanked out this morning -- hooray! But in the process, I also managed to yank away the spring that had been inside... Guess I am now taking the plunge to install the plunger.

But the more frustrating part is that the gasket for the pilot screw set is broken. I have a K&L Carb repair kit, but none of the gaskets in the kit fits. And I only found websites in the UK and EU selling the whole pilot screw set. Of course, I rather just get the gasket itself.

While I do want to keep costs to a minimum, it is not my overriding concern. I also want to know how the "ecosystem" works surrounding bike restorations. So, is it possible to get just the gasket? in the US? If so, how do I specify something that doesn't even seem to have its own part number?

What US websites do you rely on to get parts for your Skorpion?

Thank you again for all the advices through this adventure.

Getting there!

That looks like an `O` ring to me.Easy to get from a standard O ring mixed box set i bet.
Ask nicely at a local garage/workshop if you have one, such places have always helped me out.

There's a very good chance that if that O ring has become brittle and perished then the rest of the rubber seals in the carbs will have too - ethanol in modern fuels doesn't help either! Best to get a carb overhaul kit and enjoy the end results

dandywarhol wrote:There's a very good chance that if that O ring has become brittle and perished then the rest of the rubber seals in the carbs will have too - ethanol in modern fuels doesn't help either! Best to get a carb overhaul kit and enjoy the end results

Except for the float and needle valve that's underneath, I have already disassembled and cleaned everything in the carb. Luckily, only one gasket and one other O-ring needed replacement, both of which I found in a K&L Carb Repair Kit that I have already bought.

The float is not yet done because the float needle is difficult to remove. I needa research to see if anyone had already talked about it here.

WaiNYC wrote:

dandywarhol wrote:There's a very good chance that if that O ring has become brittle and perished then the rest of the rubber seals in the carbs will have too - ethanol in modern fuels doesn't help either! Best to get a carb overhaul kit and enjoy the end results

Except for the float and needle valve that's underneath, I have already disassembled and cleaned everything in the carb. Luckily, only one gasket and one other O-ring needed replacement, both of which I found in a K&L Carb Repair Kit that I have already bought.

The float is not yet done because the float needle is difficult to remove. I needa research to see if anyone had already talked about it here.

Uhhhh, it just slides on the float tang like any other.. <scratching head>

the PIN in some cases is tapered and if driven out in the wrong direction
can make things break
measure each end and see which is smaller