engine wont rev & backfires - just rebuilt

[jps601]

Challenger 1800 just rebuilt top end, rebuilt carbs beginning summer. Tried to break in new engine wont rev over 3000 and backfires thru carb sometimes, seems to idle fine. Almost sounds like engine is missing. checked plugs couple times one doesnt seem to be firing as well as the other. I rechecked compression after playing with it today still at 150. Could it be a bad coil or does rev limiter have something to do with it. I noticed that every so often I would get some beeps and it would kill the engine right after starting. But this would also kill the good engine to if i had it running at the same time. Any help would be much appreciated

 

[timmyboy76]

possible, the landyard post needs clean'n. When you say rebuilt, did you replace the RV o-ring, and if so, is the RV timed right. Possible, your off by 180*???

 

[Nate Surveyor]

One bad spark plug wire could do that.

Nate

 

[jps601]

I could see the lanyard killing both engines but that would have nothing to do with one of them not wanting to run. right? When you say RV is that rave valve? I had them out and replaced the rubber orings on them, only rebuilt the top ends Jugs,pistons, and rings.


I was thinking about bad plug wire too i might try to switch the coil and plugwires from good engine

thanks guys

 

[timmyboy76]

RV...rotary valve. But you said, you didn't remove the intake. You can cut the plug wires at boots' ends 1/4in, and reinstall,,

 

[gajipr]

Did Anyone Find The Problem I Am Experiencing The Same Thing!

 

[Nate Surveyor]

Bad alternator, with weak battery will do that on a modern auto.


So, could be not enough energy to fire the plug, at higher fuel use rate, and rpm.

Just a thought.

N

 

[gajipr]

Nate, would the Rectifier on the SEADOO be the same as a alternator on a car?
I am experiencing same backfiring and my rectifier is no good on my seadoo but my battery is fully charged and new.

Thanks

 

[seadoosnipe]

Rectifier verses alternator....?

The regulator/rectifier on a Seadoo is different than an alternator. A car doesn't use a magneto. Your lawnmower is closer to the charging system than a car.

The rectifier takes the un-regulated AC current generated by the magneto and converts it to DC current. The regulator portion maintains a steady 14 to 14.5 VDC to the battery for charging.........:cheers:

 

[timmyboy76]

Nate, would the Rectifier on the SEADOO be the same as a alternator on a car?
I am experiencing same backfiring and my rectifier is no good on my seadoo but my battery is fully charged and new.

Thanks

Disconnect the rectifier...