OMC V6 problem!

[maloneyau]

Try another flywheel.
I had an engine do this once,
The engine I had, used to miss like this but clear up when you hit the trim button. I then dissconected the rec reg and it did the opposite (run good then miss when trimming) I replaced, CDI , coils, stator, rec reg and it did not fix it until i replaced flywheel. Not sure why but it worked.
give it a go.

[looseunit225]

hmmmm sounds interesting i might try and do that!

just gotta find another V4 fly wheel as i have a low amp ignition system!

[inshoreracing]

HI,

last year, i used a 3l carbs OMC.
On this engine, we haven't limited(6800) powerpack , but 8500 powerpack.
If you are interested I can give the OMC ref.

The engine is well but after 7000rpm, time to time I have like you(I think)
with this problem, I run the 24 hours of Rouen without break!!!

really, at this rpm you have more fuel on 2 cylinder.If you change and put little jet you broke the engine(it is my experience)

regards
jm

[looseunit225]

i have replaced the ignition system with a low amp ignition system so at the moment theres no rev limiter!

you will find in my engine theres stagged jet sizes for the 2 or 3 cylinders that are a bit richer than the other ones!

[omt14f3dse]

Hi Loose Unit, A couple of questions for you regarding rev issues. You said you have changed to 16 amp electrical system, are you sure the powerpacks are unlimited as 86 - 87 big blocks were limited to 6100 (pack # 583030 or 583605) the rest are 6700 limited. Second question is, are the carbs the same as when you ran 7000 rpm as there are two different bore sizes. the other thing to check is that you have the idle and intermediate jets around the right way, as inters flow fuel all the way through to top end. Inters are in the top holes. The rev drop indicated only one cylinder is not performing as you said #3 looked off so I would start with that carb. Main jets can come loose and vibrate back to bleed screw so make sure you use notched bleeds as then you wont lean right out on fuel if this does happen. Happy fault finding I will keep an eye on the post for any replys. Cheers DSE

[looseunit225]

Cheers DSE
the way the engine preformed was one weekend it was running arround at 7,000rpms and next weekend it started playing up!

it seems my EGT gauge has gone faulty on one side thats what was giving me the incorrect reading!

and the final conclussion that i can come up with is that it was bad fuel! i drained the tank and replaced it with new fuel and bingo the engine started to preform again!

[Powerabout]

check the magnets in your flywheel to make sure none have broken and hence creating an extra north south pole