Jetting question

Hi everyone!
I'm restoring a KZ650 D2 It was going along great until the carb cleaning. While reading and studying this site, it seems that the jets in these carbs are huge! 17.5 and 120 mains. Does that seem way to big for a little 650? Even considering the pods and 4 into 1. I thought when you increase the jet size you only increase like 2 sizes.
Does anyone have any personal account of jets this size in one of these? It starts and idles fine but as soon as you increase the throttle it stalls or falls on its face. Any insight would be greatly appreciated.

what position are the needles in and from the sounds of it the carbs might be from a 1000 are they 26mm. as far as jetting goes there is no hard and fast rules it depends on a lot of variables where you are having the most problem is in the needle circuit so pull the needles out of the slides and figure out where you are at first.

Thanks Timebomb for the reply.
So I pulled the slide on my #4 carb and it is set in the middle of the 5 slots. Should i move the clip? will that make it a little bit leaner?

Mines a D1 with the vm24's. My jetting is in my sig.

Thanks,
I think that this thing severely over jetted.
It makes me wonder WTF was the previous owner thinking?
any advise on what size to order with what looks to be an old Yoshi header and pods?

I have the same jetting, pods and a lousy four into one. It remains to rich in low rpms an good in mid and top. Runs easily into the 10K

Is there a baffle in the pipe? That'll make about 1 size (maybe 2) difference on the main jet. With pods and 4-1 it should for sure have 17.5 pilots, the needle should be moved one step down (second to the bottom). The 120 sounds like too much for the main though. I'd go with a 115 if you only want to order one set of jets. If it was me I'd get both 112.5 and 115s though. If that pipe is baffled I'd start with the 112.5 and see how it runs up in the high rpms. You may have to bump up to the 115s though. I've never had a Yosh pipe so I'm not 100%, but with no baffle MAC 4-1 and pods I was running 17.5 pilots, #4 clip, and 117.5 mains. When I put the baffle back in I had to go down to 112.5 mains.

When you say 4th groove are you counting from the needle side?
Please pardon my ignorance.

Do you think that if i took the baffle out and drop down one groove it may help? I know its kind of a stupid question but i had to throw it out there.

Only stupid question is one you don't ask. Don't worry about that. Yeah, when I say the #4 clip I mean the second from the bottom (pointy end of the needle). I think the 120s would still be too much jet even if you pull the baffle out.

Thanks Anarki650 I'm going to take your advice and order the two sets of jets. it sure beats ordering and waiting twice. is there something I should know about the accelerator pump system on this thing? I've looked and not too much mentioned about it. I am so frickin excited to ride this thing its making me crazy!! But I want it right before I get too far from home.

zbandit12 wrote:

...KZ650 D2...starts and idles fine but as soon as you increase the throttle it stalls or falls on its face. Any insight would be greatly appreciated.

If not already done, would use strobe-type timing light to assure advancer unit is properly functioning and not stuck in low rpm idle position.

Good Luck!