Backfire through Carburator at high RPM

[dnemeth]

Re: Backfire through Carburator at high RPM

Check your ignition system first.
Then the fuel system and finally the engine when troubleshooting and in that order.

The first thing I did was replace the ICM and I swaped out the coil also, This thing runs fine, just cant open it up. It will move along in the water, pulling the boat up or pulling a tube but at some point past 4000 rpms, 4300 or so it starts to pop and loose power.

 

[dnemeth]

Re: Backfire through Carburator at high RPM

Ok changed the jetting back to original as it made matters worse in the water and as a last effort before i took it to the pro's replaced the pickup coil. I didnt expect it to make a diffrence but runs great. Put it in the water today and couldnt be better, celebrating with a new stereo for the boat. One other thing I noticed was that its important to be sure there is 12 volts on the timing shunt when setting the base timing, couple spots that I checked voltage at idel was only 10.2 volts.

Thanks for all of the help!!!