Mariner 30 HP 1994 Missfiring

"Serial: 0G08190

We're

"Serial: 0G08190

We're getting quite a headache from this problem, and the hot summer in Norway are comming to an end.

The problem is: The idle is pretty choppy, and when we throttle up to full throttle it feels like it's missfiring. With full speed the rpm comes and goes about 2 times a second, reving up and down. Sometimes it can work perfectly for a whole day, but mostly it's like this.

What we have done:
* New carb
* New controller unit (brain)
* New "flywheel pickup" (the timer thing beneath the flywheel, wich is not moveable on this engine)
* New plugs
* New plugwires
* Checked fuel filter and lines
* Good spark
* Good comression
* Checked all electrical wiring

More or less everything wich is connecting to the wiring system, and egnition.

The timing seems to be way off, in the engine cover it says it suppost to be at 3 on idle, and
25 on full speed. The actuall timing are: 30 on idle, and 0 on full speed and when we let it down again it sometimes and up at 50-60. On full speed it sometimes end up outside the scale...
And we have killed 2 timing guns...

I'm sorry about my poor english, and terminology...

I would love any ideas on this

Rune Stulen"

"We have been doing some more

"We have been doing some more research, and the only solution we can find is the Stator. Could a faulty stator cause these kinds of problems?

Rune Stulen"

"Third uppdate...

We tried

"Third uppdate...

We tried with a new stator aswell, but no difference. We found another way of mounting the stator, something wich resultet in much bether idle, but no power on higher rpm.

We would realy apreciate any kinde of input on this, as we are more or less out of any good ideas. We have been talking to several dealers in the area and they have no clue... The next thing would be to try some new coils, but they give a good spark so we dont see it as very likely that will work out either.

Thanx in advance

Rune Stulen"

"BTW, the correct serial numbe

"BTW, the correct serial number are: 0G081490
And the model number for the engine is: 7031302CD"

"That serial is a 15HP sailpow

"That serial is a 15HP sailpower? Anyway.

Is there any chance the flywheel got switched? There may be several different ones that can fit. All with the magnets differently arranged.
There are not to many ways to throw the timing that far off. Any flakes of rust or junk stuck on the trigger magnet will cause this. This does not leave much left.

This is a CDM system. Not a straight coil, Right? The CDM has a coil and PC board inside of it.

These packs will do this when they fail. The timing needs to be checked on every cylinder, not just #1. By taping off the flywheel with timing tape You can see if each pack is in or out of time. That happens a lot.

The red stator has an arrow clearly marking aft on whatever HP. Leave it there."

"Thank you very much for some

"Thank you very much for some usefull information, we really apreciate it
We're not quite sure if it's a CDM or coil, but we'll try to change change between the coils tommorow and time it, and hopefully the other coil is working properly. The flywheel has been there the whole time, and we have checked for dirt and it looks very good.
Then the coerrct serial must be 0G084190

I'll give you an uppdate as soon as we test this.

Thanx again!

Rune Stulen"

"I must say, thanx alot Bandit

"I must say, thanx alot Bandit

We changed the plug wires and timed the other coil (CDM) and that one worked perfectly. We have allready orderd a new one.

Like i said erlier we have spoken with several dealers and mecanics around, and nobody could figure this one out. It's very nice that you took the time to help us out

I fix computer for a living so if you ever have any problems with that, dont hessitate to send me and e-mail and ill do my best to help you out

Rune Stulen"