Black carburator

[jet busa]

Hello,

I'm just new here and got a problem with my gen 1 what i build in a jet boat. In the beginning it was running good. So yesterday i went to the lake for a rib and when i lay it in the water and it was running for 30 seconds when it shots down. After that i can't get it running. when i try to start it it just sounds like backfire or something. 1 carburator is black inside asswel. So did the timing felt or something? Maybe someone over here now better then my where to start. Thanks.

[sixpack577]

An engine misfire on that cylinder for sure.
It sounds like you may have jumped timing, possibly from a failed tensioner.
I would remove the valve cover, and the spark plugs, check the timing and compression.
If a piston hit valves and bent them, then the valve cannot close correctly, and a backfire will result under compression.
Or, you could have a failed coil, and/or another electrical issue, and the backfire was unburnt fuel igniting under compression, and there is no mechanical damage...unlikely, but possible.
You'll have to start checking things and let us know


welcome to the org

[pcs]

i like to start with the easy parts to checks, first check the plugs. once you have then off you can spin the engine by hand to see if anything is hitting if you suspect timing is off. you can also swap ignition coils so see of the missfire moves. if you swap coil 1 with 2 and number 1 starts to miss fire you found a possible issue. or you can test the coils with an ohm meter. for timing checks

Timings seems to be off please help!!! | Busa problems

Just recently replaced the head on my bike camshafts, timing chain, and tensioner . When lining up my timing marks and rotating the engine my crankshaft timing mark is off I tried setting it one tooth behind and rotating it but that's just too much . Does anybody have any advice thanks

www.hayabusa.org

[jet busa]

Thanks, gonna check it this week. Let you Guys now.

[CBXRider]

Carburetor?

[jet busa]

Hello,

Sorry for the late response. There were 3 ignition coils dead. So i changed them all and now its running ok. I dont now how old the where but its still weird that they stopped all together.

[202mphbusa]

Hello,

Sorry for the late response. There were 3 ignition coils dead. So i changed them all and now its running ok. I dont now how old the where but its still weird that they stopped all together.

What are you running for a ECU ?
maybe Reflashed ECU with too much coil dwell?

[jet busa]

original

[jet busa]

Problems keep comming. It wasnt running that good. So i checked it an hour ago and saw this. cilinder 1 and 2 are getting warm at the exhaust. 3 and 4 dont. The ignition coils from cilinder 1 and 2 are really black aswell. 3 and 4 are just like new. Is this a fuel problem?

[jet busa]

I did check the timing and valve clearance that was all good.

[jet busa]

just checked the compression and i measure 120PSI on each cilinder so thats bad. Bus isnt that weird that they all are the same?