rebuilt 28's. poppin thru pod filters! why?

I got a 79 kz motor on a 75 frame. Just had carbs rebuilt and I have pod filters and a baffeld vance and hines true sidewinder exhaust. Problem is I have some poppin coming through the filters at cruising speed in all gears. doesn't do it when im on the throttle. I have 127.5 mains and I think 117 pilots. Anyone let me know why this may be and possibly a solution to fix? Also i put brand new carb boots and clamps on the motor, so no air leaks from there.

was it fine before the carb rebuild?
poppin back through the filters is tellin me the intake valve isn't closing at the right time or properly.
any other symptoms?

leon holmes

Are you running a vaccume style petcock?

Check the vaccume tube for cracks. Is it hooked up properly?

If you are not running a vacume style, is the vaccume port blocked off properly?

If not already done, would assure valve clearances being to specs.

And also assure that automatic ignition timing advancer is fully functional, readily moving back and forth without sticking or hanging. Might need cleaning and lubing.

Good Luck!

old_skool_77 wrote:

I got a 79 kz motor on a 75 frame. Just had carbs rebuilt and I have pod filters and a baffeld vance and hines true sidewinder exhaust. Problem is I have some poppin coming through the filters at cruising speed in all gears. doesn't do it when im on the throttle. I have 127.5 mains and I think 117 pilots. Anyone let me know why this may be and possibly a solution to fix? Also i put brand new carb boots and clamps on the motor, so no air leaks from there.

these are vm series carbs? 28 mm?....it could be me or that its late, but those jet numbers dont seem right.....sounds like the ghost of wg fishing....

carbs are stock from the 79 motor. as far as I know, the 79 and 80 model came with the acc pump on thes carbs. But I'm not 100% on that. all vaccum lines have been replace with new ones and as far as I know they should be working properly. petcock is a dual feed. carbs have only one fuel intake line on them, so only one of the feeds on the petcock is being used and the other is blocked of. it does leak a little from the blocked off side, from the clamp not being tightend. possibly the culprit? I have dyna 3 ignition and coils. also when I hammer on the throttle, I get this pinging type noise coming from the engine, hence maybe an outtawack valve?:huh:

old_skool_77 wrote:

carbs are stock from the 79 motor. as far as I know, the 79 and 80 model came with the acc pump on thes carbs. But I'm not 100% on that. all vaccum lines have been replace with new ones and as far as I know they should be working properly. petcock is a dual feed. carbs have only one fuel intake line on them, so only one of the feeds on the petcock is being used and the other is blocked of. it does leak a little from the blocked off side, from the clamp not being tightend. possibly the culprit? I have dyna 3 ignition and coils. also when I hammer on the throttle, I get this pinging type noise coming from the engine, hence maybe an outtawack valve?:huh:

are you sure about previously stated main and pilot jet numbers?

yeah im sure. the shop that rebiult them told me the size should be fine. they are stock for that carb. i was actualy gonna raise em up to 130 mains and 120 pilots but the carb guy told me that the stock ones should be fine. but i was kinda sketchy.

old_skool_77 wrote:

yeah im sure. the shop that rebiult them told me the size should be fine. they are stock for that carb. i was actualy gonna raise em up to 130 mains and 120 pilots but the carb guy told me that the stock ones should be fine. but i was kinda sketchy.

130 mains and 120 pilots on a vm series 28 mm carb
mounted on a 1000 cc motor? sketchy is an understatement....maybe another member can help.......
am i the only one this doesnt make sense to?....?????????

old_skool_77 wrote:

... when I hammer on the throttle, I get this pinging type noise coming from the engine, hence maybe an outtawack valve?:huh:

Pinging -- Pinging under load ???

Possibly predetonation (spark knock)? If not already done, would read sparkplugs (any tiny aluminum balls?) Possible incorrect ignition timing? Wrong plug heat range? Might burn hole in piston. :pinch:

Good Luck!

the plugs are stock which and they are B8ES NKG brand. they are new. i dont hear anything out of the ordinary when i ride normaly. only when i lean foward to hold on and hit the gas is when i hear it. when im toolin along at cruising speed in any gear is when i get some poppin outta the air pods. doesnt do it when im under load.

took this bike to have carbs rebuilt and tuned properly at a bike shop. should I take it back???