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Spark+fuel=no fire

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Bjsmith919

Regular Contributor
At it again with this 98 Fast Strike. #3 cylinder will not fire. Has spark, tested with a gap tester, strong spark will jump a 3/4 inch gap and the plug is wet but it will not fire. Has 123psi on that cylinder, 125 all on the other 3. Can pull plug wires and all have an effect except #3. Anybody ever run into this problem? Once again, I'm at a loss.
 
Find/rent a bore scope or camera and take the plug out so you can see what's going on inside. I bet it's mechanical not electrical...
 
Swap plugs around and see if it follows the plug? Just because it ohms out good means nothing it could have a cracked insulator leaking internally.
 
Do you see fuel spitting back out the #3 carb when running you could have a bad reed or leaking manifold gasket? You have spark and compression I would look into fuel supply. Pull the #3 drain plug on the float bowl and see how much fuel comes out.
 
Sorry for the delay in responding, been very busy at work and hadn't had time to mess with it until yesterday and today. I have a bore scope and everything looks fine inside the cylinder. If there was a hole in the piston wouldn't that effect compression? Also, tore it down and 3 reeds were opened about a eighth of an inch on that cylinder. Purchased new reeds from a local marine mechanic and got them installed tonight. Cleaned fuel system out good but by the time i had everything back together it was too late to fire it up and see what i have. Dont want to make the neighbors mad. Gonna fire it up tomorrow and see what I have. Will update tomorrow. Thanks for the replies.
 
Ok guys, here is where i stand now. Ended up replacing reeds on 2 and 4, replaced all 4 carb bowls, they were warped and cracked some kinda bad. Went through and cleaned entire fuel system on engine, took everything fuel related off and apart and inspected good and put back on. Been on the water 3 times so far and it runs alot better than it was. Can get back to wot, 5300rpm. One thing i cant figure out is if i really get on it from a dead stop it still has a little stutter around 3500rpm, if i take it easy on the throttle it runs like a top all the way to wot. Sorry it took so long to get back to you guys, been very busy at work, just had inspection and getting ready for golf season. Anyway, thank you everyone for all the input. Lord I hope this post doesn't jinx it.
 
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