Popping and backfiring

[kparkfan]

Thecafekid and I just adjusted my valves and synced my carbs to the best of our ability. The bike was running good and now it is back firing and popping again and the gas milage has gone down hill. What the heck could be causing this all of a sudden?

[TheCafeKid]

Popping and backfiring from where? Pipes or carbs? How many MPG are you getting? Dont say you only got 85 miles out of the tank, cause that means absolutely nothing. You need to track the mileage. Could be sediment in the tank...could be a bazillion different things..

[kparkfan]

Its coming from the pipes.

[TheCafeKid]

Well, generally, popping from the pipes is a sign that its lean. But if your gas mileage has gone high, that doesnt make much sense. Im assuming you've replaced all the orings in the carbs when you did them? Were you able to get the pilot jets out when you dipped them? I ask because i have a couple times not been able to when someone has trashed the heads on them, and had to soak the carbs with them in. Its ok, just requires an extra amount of attention to them to assure they are free and clear. You are certain your floats are set correctly and that that petcock is working? It looked a little funky last i saw it.

[kparkfan]

Yeah i got all of them out but had to replace one due to it being bent. I'm thinking the same thing about the petcock.

[chef1366]

Are the carbs all the way in the boots?

[TheCafeKid]

Are the carbs all the way in the boots?

Thats a good point too.. If they're old and very "short" as in they've dried up so much its at the very very end of its extension to get it on there, they could easily vibrate loose.. Ive also seen them "fit" but were just so old and sacked they wouldnt tighten...You might look into getting an new set..12 bucks or so a piece..

[kparkfan]

Yep all 4 boots are brand new.

[Larry D]

Are all the the sync screws back in tight ?

[kparkfan]

yep those are all tight. i'm going to tear back into it this weekend and double check my valve clearances.

[TheCafeKid]

yep those are all tight. i'm going to tear back into it this weekend and double check my valve clearances.

The AIRBOX boots are new???

[kparkfan]

no not those.

[TheCafeKid]

no not those.

ALLRIGHTYYYYY THEN.... Get on it... Its not your valve adjustment.