CDI unit

[mowerman]

Just wondering if anyone has had any trouble with or had to replace a cdi unit.

I have a 2 stroke 90hp Yamaha and had the 100hour service done today.
The mech wasnt happy with the motor at idle. Sometimes, not always, the motor seems to running on 2 cylinders at cold start.

So we went for a run off Wello this arvo. Cold start was fine and idled perfect.
Got to the end of the beacons, 2minutes run, and the mech says, turn it off and restart. Restart, runs, stops after 3 seconds. Did this 5 times untill the mech took the cover off , took the lever off the cdi and manually advanced something.

Fired up and kept on running,,, and didnt do it again. After a lot of starts.

Also, if you take 1 of the plug leads off at idle, the revs increase.

The cdi unit apparently controls everything to do with the motor.
Maybe one of the sensors is stuffed.

Has anyone had any of the above problems or had to replace the cdi unit .

Rod

[BM]

Its not very common but they do fail. It is likely to be quite expensive.

Cheers

[bay_firey]

If they are anything like the stator on a 115 merc then brace yourself.

I have just had to replace the stator on mine $530.00 for the part plus the fitting
What started out as a relatively well priced service and water pump impellor soon gave the old wallet a heart attack

[mowerman]

10 minutes to replace


Around a grand for the unit.

Thats a lot of lawns..

[blaze]

pm to BM for a price, looked after me on a reg
cheers
blaze

[FNQCairns]

Was that the middle plug lead that was removed? these things are spark advance timed in a strange way, the middle cylinder timing is in a way independent of the other two if my memeory serves me correct -not totally sure, suspect that possibly the problem may be elsewhere, I would get a second opinion before replacing the CDI and if you do dont let the cat out of the bag to the second opinion first.

Lot's of parts replacement techs around, not many can diagnose well the complex circuits, it's your money!

cheers fnq

[captain rednut]

sounds to me like the carbys need a blow out and dont forget the basics yamahas dont have common electrical faults. if your worried get a second opinion

[mowerman]

It hasnt happened to me before. But then again I dont usually run the motor for a couple of minutes then turn it off and start again.
Mostly it runs for 15 minutes to half an hour, sit for a couple of hours watching the view, then away we go again.
The mech has recomended starting it at least once for the next couple of days, letting come down of fast idle,stop and then start again and see what happens.
And looking at the wind forecast I wont be doing much else with it.

FNQ...It was the middle lead.

Second opinion was the next thought..

Rod

[FNQCairns]

It hasnt happened to me before. But then again I dont usually run the motor for a couple of minutes then turn it off and start again.
Mostly it runs for 15 minutes to half an hour, sit for a couple of hours watching the view, then away we go again.
The mech has recomended starting it at least once for the next couple of days, letting come down of fast idle,stop and then start again and see what happens.
And looking at the wind forecast I wont be doing much else with it.

FNQ...It was the middle lead.

Second opinion was the next thought..

Rod

Ok then, if the middle lead I will go out on a limb and say that your problem (if you have a real problem and not just simply tuning somewhere) is elsewhere. Glad you will be getting someone else to look at it.

cheers fnq

[dnej]

Mowerman.where do you hail from?
David

[mowerman]

David


Im at Alexandra Hills. In the Redlands.

Rod