Im pulling my hair out......argh

ok, my buddy just picked up a sweet 3800 mile 77 kz 650b1. Motor is quiet as all, the carbs are 26mm off a kz 1000 im guessing, 4 into 1 vance and hines with the baffle chopped half way, pod filters (the oval type). The bike runs ok idling but is spitting and popping like crazy out of the pipe, and has no top end rpm's, it has 112.5 mains, 17.7 pilots, and the needles clipped to the 4th slot. Im thinking on going to 110 mains. It is running way to rich because if you stand behind the bike when it's running your eyes tear from the gas smell.. Also if you turn off the choke it dies.

Make sure it's not flooding over and the float levels are set right before you change the jets.

Also if you turn off the choke it dies.


Plugged low speed jets and passages? Has it been parked for a while?

ya, it was parked for a while before he got it, but we took the carbs apart and cleaned everything.

Would think that the plugs would be wet... yes/no?

The following chart is for larger displacement engines but the carbs should be close to the same in OEM jetting... I think anyways, other KZ650 owners can chime in for sure....

Actually, where's Blue Meanie or Kawisakiman.. PM them...

as you described the popping i also thought idle circuits got some clogs......

TexasKZ wrote:

Also if you turn off the choke it dies.


Plugged low speed jets and passages? Has it been parked for a while?

Ya im going to pull the carbs again tommorow and cleand them again.. I knoticed the battery was almost dead on it also, so i will charge that tonight, also it has b-8es plugs, maby that is part of this problem? I alkways run the b-7es in my 650 and never a hickup. The bike has theses shitty emgo pod filters on it....maby that is whey its not running great eather?

With those carbs, pods, and reduced baffle pipe that bike should be jetted at least at 115 main and 17.5 pilot. Running the same set up I was at 117.5 mains, 17.5 pilots and #4 clips and had perfect plug chops on all three circuits (idle, midrange, and WOT). The rich I'd guess almost has to be bad float heights. Also, check the valve clearances before trying to dial the carbs in, if they're not right on tuning those 26's correct will be a bitch.

I have a set of 4 115 mains in my tool box. I will adjust the floats tommorow. I checked the valsvs and they were good. He called me and told me he ordered a set of those APE hi flow air filters. Here is the link www.kzzone.com/carbs.html . Part # 005-122

Have you done a compression check on this engine???
If compression is way off it will never run right.
maybe adequately, but not right.

Make sure to perform a good bench sync on the carbs after cleaning them out with carb-cleaner and compressed air.

Check all the fuel heights with the carbs on the bike, as fuel height is absolutely critical to performance.

Oh yeah, get a manual. It pays for itself in the first repair!

Cheers, and goodluck.

Put the 115 mains in and it ran better. Then i figured for shits and giggles i would check the timing. It was way off.........i adjusted it and holy crap it idles so nice throttle is perfect and it runs like a red heded step-child. The only problem it has is when i run it at high rpm's it braks up and dies. I got it back home pulled the point's cover and found out the 3 screws for the points plate were completley rounded, thought i had them tightened enough......but i guess not..... so the plate would move around and make it run like crap. Going tommorow to get new ones.