Rebuilt Raptor Wont Stay Running

[tcoop212]

I rebuilt an 02 raptor 660, it runs for a while (20-30 seconds) and then dies. It seems that It is running out of gas, because before it dies it revs up  very high. I pulled the petock valve out of the tank and checked the filters, and they were clean, I opened up the carb and cleaned all the jets and stuff. It seems that right after I did this it was running longer. So maybe I need to do this again. Could it be the air mixture being off? When it is running it is rough sounding and backfires a lot (shooting flames). Thanks for any input.

Tristan

[Peelz]

could be a problem with floats?

[Krandall]

revving up REALLY high and dieing right away sounds like a symptom of an air leak, a very lean scenario

[Peelz]

revving up REALLY high and dieing right away sounds like a symptom of an air leak, a very lean scenario

oh oh.... well said Krandall.

on that note: check your intake boot for tight seal. 660's had issues with that. mine had zipties keeping it on. and make sure youre getting enough gas in both bowls.

[tcoop212]

Im almost sure that it is just running out in the carb, after it revs up and dies it wont restart for a few minutes (until the carb fills back up??)

[Krandall]

my only experience is on my 66 coronet. I had replaced lifters last summer, put the intake back on, carb mounted. When I went to start it. It did that EXACT same thing. It'd rev up super high, die. wait for the fuel pump to push more gas in.. (lather, rinse, and repeat).

not that it's run long. Do you have a new plug in there? If so, what color does it look? That should at least give some sort of indication of lean/rich..

the backfiring is a symptom of extreme lean conditions.  (If it ran good prior to the rebuild, this really makes me think you got an air leak somewhere)

[tcoop212]

Ok, well im not sure what I did, but I cleaned the carb and reset the air screws on the front of the carb, and not it runs. However, it still is backfiring link crazy when I rev it up it runs great and has all kinds of power. When taking off it sometimes will backfire/burp and will pop a wheelie running crazy. I am not to well read on the raptor carbs, do they have different jets for idleing/low rpms? Any help would be appreciated.

Tristan