ETZ 251 mis-firing after 40 minutes riding.

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Re: ETZ 251 mis-firing after 40 minutes riding.

Postby Blurredman » Wed Feb 01, 2017 9:46 am

rodge70 wrote:Yes it is an aftermarket cdi unit

do you know if ac or dc powered,usualy ac ones are larger than dc powered units iirc and run on a high voltage from stator,could be worth checking ac output from the off then when mis-fire happens


The CDI is powered from the battery directly so is DC.

Voltage doesn't drop when bike stalls and lights and ignition continue to stay on.
1972 MZ ES250/2 - 16,000 miles - The project! :)
1979 Suzuki TS185ER - 9,000 miles - Mud :)
1981 Honda CX500B - 91,000 miles - Long Distance :)
1987 MZ ETZ300 - 38,000 miles - Sun :)
1990 MZ ETZ251 - 49,000 miles - Commute :)

ftp://blurredmanswebsite.ddns.net/Vehicle_Documents/MZ_Documents/
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Re: ETZ 251 mis-firing after 40 minutes riding.

Postby Blurredman » Thu Feb 02, 2017 3:34 pm

Interesting development chaps. Today I decided to double chech wiring, clean contacts etc. But before I did anything I turned the main beam on the switch but the bulb didn't light. It seems there was contact issues between bulb contacts and holder, which I have reinforced. I al replaced the fuse box with new one and cleaned terminals.

I started up the bike and successfully went up and down the road with lights and indicator going. No stalling when coming to a stop.

I understand why if a dodgy connection to the bulb could cause extra resistence because the light switch is also the ignition switch but Question:- if it was the bulb connection, why would it stall even when the lights weren't turned on???
1972 MZ ES250/2 - 16,000 miles - The project! :)
1979 Suzuki TS185ER - 9,000 miles - Mud :)
1981 Honda CX500B - 91,000 miles - Long Distance :)
1987 MZ ETZ300 - 38,000 miles - Sun :)
1990 MZ ETZ251 - 49,000 miles - Commute :)

ftp://blurredmanswebsite.ddns.net/Vehicle_Documents/MZ_Documents/
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Blurredman
 
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Location: South Wales

Re: ETZ 251 mis-firing after 40 minutes riding.

Postby Blurredman » Thu Feb 02, 2017 4:29 pm

Update:

Positive I had resolved the issue after a quick test, I went for a longer ride and it was unsuccessful.

It was running so smooth on the quick run but misfired and stalled at every juction on the longer run around town. Its not to do with lack of juice..


Things checked or changed so far:

Spark plug,
Coil,
Regulator,
Diode plate,
Fuse box,
Replacement wires and connections,
Electronic ignition,
New battery,
1972 MZ ES250/2 - 16,000 miles - The project! :)
1979 Suzuki TS185ER - 9,000 miles - Mud :)
1981 Honda CX500B - 91,000 miles - Long Distance :)
1987 MZ ETZ300 - 38,000 miles - Sun :)
1990 MZ ETZ251 - 49,000 miles - Commute :)

ftp://blurredmanswebsite.ddns.net/Vehicle_Documents/MZ_Documents/
User avatar
Blurredman
 
Posts: 1227
Joined: Sat Feb 09, 2013 3:59 pm
Location: South Wales

Re: ETZ 251 mis-firing after 40 minutes riding.

Postby DAVID THOMPSON » Thu Feb 02, 2017 6:58 pm

AIR LEAKS IN INTAKE OR EXHAUST AFTER IT WARMS UP
head leak after warm up
2 smokers can be a pain some times
dave
Dave 2002 MZ RT125+1995 Saxon Tour(500cc)
1997 MZ 660 Traveller+6/13/09 WV USA
"IN the end times the IDIOTS will be in charge
of everything"
"I like the road less traveled if it's PAVED!"
wd8cyv at yahoo dot com
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Re: ETZ 251 mis-firing after 40 minutes riding.

Postby Blurredman » Fri Feb 24, 2017 7:36 pm

Right.

Well I had indication that the newer reproduction coils are crap, so I put on the original, but I checked for air leaks. There was a slight air leak on the intake.

The fact of the matter is that the bike did the initial 'apparent coil overheat indicator' when doing 60mph down the motorway, which I think was really a slight soft seize occuring.

I put the old coil on and have been riding around on the bike for a while and there seems not to be any issues with stalling, nor electrical loss nor other symptons of a poorly running bike..


Thanks David!
1972 MZ ES250/2 - 16,000 miles - The project! :)
1979 Suzuki TS185ER - 9,000 miles - Mud :)
1981 Honda CX500B - 91,000 miles - Long Distance :)
1987 MZ ETZ300 - 38,000 miles - Sun :)
1990 MZ ETZ251 - 49,000 miles - Commute :)

ftp://blurredmanswebsite.ddns.net/Vehicle_Documents/MZ_Documents/
User avatar
Blurredman
 
Posts: 1227
Joined: Sat Feb 09, 2013 3:59 pm
Location: South Wales

Re: ETZ 251 mis-firing after 40 minutes riding.

Postby Blurredman » Mon Mar 13, 2017 6:00 am

Just a little update on this. As my above solution was incorrect!


Turns out that the air leak didn't case this issue. It was still the coil, and the bike continued to break down. I have currently got another spare coil on it and so far (fingers crossed it is working), however I am not jinxing myself this time. I will give it a week before I consider this issue resolved, but likely the problem was the coil (it was very warm!).
1972 MZ ES250/2 - 16,000 miles - The project! :)
1979 Suzuki TS185ER - 9,000 miles - Mud :)
1981 Honda CX500B - 91,000 miles - Long Distance :)
1987 MZ ETZ300 - 38,000 miles - Sun :)
1990 MZ ETZ251 - 49,000 miles - Commute :)

ftp://blurredmanswebsite.ddns.net/Vehicle_Documents/MZ_Documents/
User avatar
Blurredman
 
Posts: 1227
Joined: Sat Feb 09, 2013 3:59 pm
Location: South Wales

Re: ETZ 251 mis-firing after 40 minutes riding.

Postby DAVID THOMPSON » Mon Mar 13, 2017 11:09 am

use bmw 1970 to 77 /5 6 or 7 coil with a resistor there 6 volt running 2 in series in the BMW application

in 40 years i have never had a bad one
have even ran them in my cars
dave
Dave 2002 MZ RT125+1995 Saxon Tour(500cc)
1997 MZ 660 Traveller+6/13/09 WV USA
"IN the end times the IDIOTS will be in charge
of everything"
"I like the road less traveled if it's PAVED!"
wd8cyv at yahoo dot com
User avatar
DAVID THOMPSON
Moderator
 
Posts: 5150
Joined: Sun Nov 23, 2003 11:01 am
Location: Parkersburg, West Virginia USA .questions answered MZ 95 up, BMW 1953 to 1979 and ham radio WD8CYV

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