ULTRA/XCR 680 Intake Noise Burble

[wwtbuick]

I have a question for the 680 pros I have a 96 engine I put in an 97 XCR chassis and it has what some have called a burble and slight popping at low speed has stock 97 XCR pipes and a SLP intake on it I am not familiar with these sleds to know if it is just intake noise and carb mixture or something else it constantly has the burble at slow speed but cleans out and runs great, I did do a compression test on the engine and it has 75 psi on all 3 so I ordered new rings for it, any ideas whether the lower compression will make this problem worse or just the nature of the lower speed not cleaning out? I different guy told me it was missing but I mostly sure it is not electrical. Tell me what you know any info is needed Thanks

 

[550iq]

The opening and closing of the reed valves at lower rpm's will emit a popping sound. Not sure what a burble sounds like. Sounds like the engine runs great though.

 

[wwtbuick]

Yeah popping sound also just wasnt sure how to describe it, just obnoxious sounding compared to my other stuff I know the airbox is supposed to muffle that, I think with the SLP intake on it makes it louder just wasnt sure what is normal.

 

[550iq]

When you do your rebuild, might just as well check your reed valve conditions. Broken, chipped, and worn out reeds won't be doing you much good.

 

[X2Freeride]

Ditch the SLP air box and go back to stock, only hurting yourself running that box.

 

[wwtbuick]

Yeah I had considered that also, I need to get one for it

 

[lurker]

Compression is way too low, don't know how it even runs, burble down low means rich, popping means lean!

 

[wwtbuick]

I got the rings in it and have 100 psi now, out of snow to do much tuning yet I will keep messing with it.

 

[CB.8]

Make sure are your choke plungers are free and in proper adjustment.