engine speed cycles 1996 challenger 787

[KenStauffer]

I have read a lot of the threads, and previously my seadoo would idle ok, but rpms would not go much higher than idle, and if you increased throttle the it would sputter and often backfire out the rear carb.

I rebuilt the carbs pretty carefully and believe that I have things right. Now the engine starts right up and idles great, but if you give it gas it does what i call "cycles" or races. speed changes in a rhythm sounds like vroom, varoom. Sorry for the lame explanation but i doth know how to describe what it is doing.
this cycle is fast at 1/3 throttle and becomes more pronounced and slower over 1/2 throttle. also no longer backfires

I ran for a while and the plugs both are warm and look the same. It sounds much better than before, but still not there.

any help would be appreciated!

 

[manolocross]

Sounds like low speed needles on carb are too lean. Did you set needles to factory spec?


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[KenStauffer]

They are set to 1 turn and I replaced o rings.

 

[KenStauffer]

Also I have a better description now. The engine speed surges. The tach is not working but I would say it goes from maybe 1500 to 4000 rpm at 1/2 throttle it does it maybe every 1/2 second so just revs from lower sped to higher over and over. I am taking apart the fuel selector today. It does not have grey fuel lines

 

[KenStauffer]

I have another update. I tried putting it in gear and it seems to run pretty smooth and does not do this surging. Is this normal? Also I don't know see how I would get the fuel shut off back once I removed it, anybody have and ideas about accessing fuel shutoff on 96 challenger? I can see how to remove it, bit am afraid to as I don't think I can reach to put it back.