weak spark 125 force 1988p

[fisheymikey]

hello everyone!

i have to say that i have teared this engine a part and put back together at least 3 times without counting individual problem seeking issues.

i have 2 concerning issues i want to triple check before i throw in the towel and just wait until i have engine failure.

just some basics info before the same ideas come out or hypothesis. i have 141 on all cylinders, redid all wire connectors, carb adjusment, link and sinc,reed pedal inspection, puddle valve inspection,stator reading on idle 220v#1 pack 180#2, 596oms resistance, triger 47 oms, clear fuel filter full and running strong,excaust and headgasket changed,

#1 issue is i compared to another 125 force and found that the spark was alot stronger that mine. i saw a strong blue spark mine was blue but half the intensity. the only thing that i did repair since the last spark inspection was my starter was very weak it did not turn as fast as my current rebuilt starter, would a faster spin of the flywheel will create a deeper and bluer spark?

#2 my most concerning one, the #4 cylinder always seem much more leaner than all the rest.with compression being good i cant see how i have a cracked or headgasket failure. can it bee something to do with the gas not reaching the spark plug?


the engine sounds fine after new flywheel due to flywheel slot key expantion that created a hesitation during idle. i guess what im looking for is the basics. even if i did all the testing in the world sometimes i need to go back to the begining. for a weak spark what would be the most likely culprit? also the same for #4 cylinder what would be the most likely culprit?

because i have time to think and trouble shoot engine threw the winter months without worrying i want to redo my check list and go thoroughly.

thanks guys

 

[jerryjerry05]

No Title

#1 Yes stronger spark the faster it's turned.
Sometimes if a motors not turning over fast enough it's possible the bearings in the top of the drive are corroded and making it hard to turn.

#2 you check the reeds?


My stbd. motor.(3cyl) The bottom plug always looks like it's new.
No oil or carbon. The others only a bit of discolor and oil after hundreds of hours of running???
Maybe it's normal for yours to be that way.

Take a spark tester and check the spark while running.
It should jump 7/16in.

If it's still weak then you might need a stator.
Double check the grounds.
Any dark/ hot spots on the stator?

Even "new" parts can be defective.

 

[fisheymikey]

well Jerry!! Are saying that even after hundreds of hours your plugs look relatively new? well thats good to hear maybe now ill just let go and focus on running the engine.

yes i did check the reeds took them out of the housing closed perfectly. barely see any light threw the reed and its housing.

weird that the bottom cylinder acts that way. Any theories why?

 

[jerryjerry05]

Nothing other than it might get more fuel trickling down and washing the plug??
That's a WAG on my part.(wild a&% guess)