problems with rebuilt force motor

Hi guys. Any help would be appreciated. Recently rebuilt a 1987 85hp force motor. Had to bore cylinders .030 over due to scoring. Engine wants to run but seems to be out of time. Backfired a few times. Wondering if stator could be bad and causing this. Flywheel is fine. Checked it and key a dozen times. Also wondering if carbs need to be re-jetted for bigger bore size? Thanks.

Stator shouldnt be causing this since it is acting like a alt. on a car. Did you clean the carbs before trying to run this engine? Did you put the stator back in its orig. position they xcan be put on backwards It should even say on the top this way for such and such hp. Sounds like timing to me

Cleaned carbs three times. Re-adjusted linkage. Seems like timing to me too but I don't really see how they can lose time unless flywheel moves. I will take stator back off later today and see if it says anything. I didn't know that u can put that on wrong. I'll check that. Thanks.

What about the plugs they all getting spark? Do you have a manual to go off of? What about the fuel is it old?

All plugs are getting spark. Good compression in all cylinders. I did get a manual for it. New fuel. New primer bulb and hoses. And it doesn't say anything on stator. Because of wires, it looks like its in the right spot. I could probably turn it ninety degrees. Could a bad.trigger cause backfiring? Or would it not get any spark with bad trigger?

Did you pinpoint the cause of the scoring ???----------You must otherwise it will happen again.------When cleaning carburetors did you verify all jets clean ( taken them out for cleaning !! )--------Do the ohms check on the stator coils.

Yes, the triggers on the prestolite ignitions can do some funky things, but as racerone asks, did you correct the original problem. The scored cylinder was the result - not the cause.

And NO, for 30 thou over you don't need to rejet. Going from 3.310 to 3.313" in diameter, with the same stroke of 2.8" in the cylinder, results in a miniscule increase in displacement (that cylinder started at 24.0937 cubic inches of displacement and after boring became 24.1374 cubic inches - a whopping increase of .04 cubic inches)

Before you start happily swapping ignition components (a trigger goes for over 400 bucks, the CDI box somewhat above 500) you should get it into a shop for some DV testing at different rpms to see if the components are working like they should (your manual should have the expected voltage readings for trigger, stator etc, but they can not be tested without a DV meter or a DVA adapter for a standard multi-meter). You don't want to drop a grand on a couple ignition components only to find you have a chaffed ground wire that's arcing on you...

Got this engine and boat because it wasn't running. When I took it apart, I noticed somebody had put a new head gasket on backwards. Thus it was blocking water pocket. I think that led to overheating and burned the ring to piston causing the scoring. So I believe it should be good when I get it going. And I did take out all jets and made sure they were working. I'll try the ohms test on stator this week and start there. Thanks for the inputs.

Alright. Stator seems to be fine. But there is a half circle on the inside of it. Is this some sort of timing mark? Does it need to go a certain way? Wondering if it installed in the wrong direction and causing it to be out of time.

3.310" + 0.030 would now be -----------------3.340"

Absolutely racer. Think he misplaced decimal point..003" instead. but engine is bored to 3.340.

my bet says its the timing

Thanks for all the help. Boat started tonight. Stator was the problem. The one that I installed was for a four cylinder. Mine is a three. Put original Stator and trigger on and a little adjusting and she popped off and is running great. Next test is the lake. Thanks again for the inputs.