Popping or cracking sound from 4.3 L Bayliner

[Philom]

Have a 2006 Bayliner with 4.3 L MPI engine. Worked great for me last year and first couple times this year. Just the other day it would "pop or crack" when pushed to full throttle. Engine starts and runs fine, can push it up to 3/4 throttle and take it up to cruising speed or pull 2 tubes with no problems but when pushed to full throttle it reacts and bogs. As soon as I let off on the throttle everything is fine and runs great. Changed all fluids last fall, changed fuel filter & in spring put in a can a Seaform to take out any water in the fuel. This is only first tank of fuel for the year. Thoughts???

 

[sstocker31]

Re: Popping or cracking sound from 4.3 L Bayliner

Sounds like detonation to me.....maybe some less than stellar fuel. Top it up with some premium fuel and run it on the lake for 5 minutes at low to mid speed (to burn out all the older fuel in the carb and fuel lines), Then try a full throttle run.

 

[Philom]

Re: Popping or cracking sound from 4.3 L Bayliner

Could be, I put 3/4 of tank of mid grade fuel on top of last years fuel and added a can of Seafoam to help with any water issue. Could it be plugs or plug wires? Any way to test them?

 

[Philom]

Re: Popping or cracking sound from 4.3 L Bayliner

Problem solved. In the end, it was a poor coil wire. Took it out in the dark and could clearly see it arcing against other wires and when you touched it, it would follow your hand. Replaced the coil wire and runs like a top.