kz650 jetting

Curious what main jets anyone who has pods with 4-1 and 750 cams might be running. Currently i'm running 115's but I think I still need to go bigger. Pulls hard to about 5,500 then starts missing and acting like its running out of gas,

Plug chops?
Steve

Why the different camshafts? Are a 750 cylinder block & pistons installed or something?

I'm running the 1980 750 cams pods and V and Hines header along with the 700 kit...... 750 cams have .330 lift vs .304 and 10 degree's more duration ..... Ran 17.5 pilots...... clip on the 5th (stock is 4th) and 112.5 mains before the cam and kit .... 117.5s now and seems to be very close........

I had a 750 donor sitting around while putting this one together. I've heard some guys use the 750 cams as an upgrade to gain a little power. They were sitting there, so it was more of a why not use them kinda deal.

Thanks for the feedback. I think i'm headed in the right direction. We had a day about 25 degrees warmer then the last time I rode and the bike was better up top, but still missing quite a bit.

1977 KZ650, 810cc big bore kit, 10.5-1 compression pistons, Stock VM24 carbs, 82 GPz750 cams, RC header and ported head.
Mains- 118 Dynojet main I believe that is about a 110 or 112 mikuni
Pilot- 17.5
Needle clip in the 4th slot from top
Runs perfect.

Sounds like I might be a little rich then Baldy........ will need to do some plug reading this summer.

That has me second guessing myself..... I should have mentioned i'm using the OEM equivalent jets from jetsrus. They may flow a little less then the genuine jets. Pilots are 17.5 and the clips are in the 4th position down. I'm still going to try the 120's and see how it responds. Hopefully I can get rid of the miss and get some accurate plug readings. Thanks again for all the replies!!!

Looks like I have also been fighting an electrical issue. I ended up with the best results with 17.5 pilots, 110 mains(may be a hair rich still but need to straighten out the electrical system before I try to mess with the jetting any more), and the needle clip in the 4th position down. I found that the voltage would dip down below 12 volts when revved(battery is in good condition, only 2 months old and holds a charge with no issue). I've been going through cleaning connections(found a very questionable one at the field coil in the stator cover) and getting the voltage regulator adjusted to try to keep the voltage closer to 14v-15v. I haven't had a chance to ride it since the last round of adjustments. I'll report back what I find. I'm still suspicious of the ignition coils. They ohm out okay but I still think there may be an issue with them once they get warmed up. Might go ahead and order a set of the grey coils from z1(the bike has the electronic ignition and coils from the same 82 kz750 that I took the cams out of). We'll see how it does on the next ride... Thanks again for all the feedback.

Just wanted to post an update to maybe help anyone with similar issues. I have replaced the charging system with the one from my 82 750 ltd parts bike and installed a new regulator( this helped a ton but didn't cure the problem). It would pull through to about 7500-8000 rpm and start breaking up really bad. I swapped out my 110 mains for 105's and installed my new dyna s and green coils. Then it would pull hard through redline with no miss, but was down on power in the mid-range. Just lowered the clips on the needles from the 4th to the 5th position (richest setting) and went for a short ride and the power is back in the mid-range and it stills pulls hard through redline. Next step now that it will actually run without missing through redline is plug chops. I have a feeling I may need to bump the mains up to 107.5 or back to the 110's, I shouldn't have changed the mains and the ignition at the same time,

I have to keep telling myself ONE THING AT A TIME. :dry:
Steve