popping 810 (bs34s)

After the 810 build the bike rode like a dream (was a 650), anyway, now that the torture is over breaking in the pistons, i am starting to get on it a bit more and i notice that she pops quite a bit when i let off the throttle at 5000+RPM & 3/4+ throttle. She has a set of BS34 carbs with pods and 40/140 jets. They were super clean (my doing) when i first woke the beast after the rebuild and there was no popping at all.

I am of course going to clean them and then clean them again tonite. If the popping persists what should i look to do with the main jets? or any other ideas?

I think i didnt notice this before because i was breaking the pistons in as they say to (wiseco) not 3/4-full throttle.which by the way is extremely painfull!!

Thank you for any and all help.
-patrick-

The popping your getting is normal for a sudden lean condition that occurs at high rpm when the throttle (is released) returns to the pilot circuit.

You can turn the pilot mixture screws out (on top front of BS34s') 1/4 turn at a time (out) to add more fuel mixture into the pilot circuit. This is ok up to a max of about 4 turns.

This normally works, but if not, pilots will have to be changed to next larger size.

Cheers, good luck.



PS. Has the bike been properly re-jetted? Have you used different jet increments? With that setup, a larger main and raised needles may be required.

like tek9 said turn out your fuel screws abit at a time equally on all 4 carb's that should get rid of your problem

Air leaks in the exhaust can make them pop as well. Sometimes collectors don't fit properly.

A little popping is normal, if excessive you should try larger pilot jets.

If you have header exhaust leaks at the exhaust port (gaskets not sealed) the popping will sound WAYYYYY louder like firecrackers.

been there, heard that....:laugh: