26mm carb help

ok this should be easy for all you guys that love speed.i have 79 kz1000 ltd with vance and hines header[4 into 1]and pod filters.carb is not running good at all.bike will idle with coke on and half way down only,if i give it gas does nothing.what should the jets be with this set-up?thanks so much.

b.tracy79kz wrote:

ok this should be easy for all you guys that love speed.i have 79 kz1000 ltd with vance and hines header[4 into 1]and pod filters.carb is not running good at all.bike will idle with coke on and half way down only,if i give it gas does nothing.what should the jets be with this set-up?thanks so much.

Sounds like the pilot circuits are dirty to begin with. The V&H pipe can have a profound affect on stock jetting but it should idle without issue. I would clean them as the starting point and go with this jetting.

If carbs are original 26mm units:

Leave fuel pump rod alone.

Pilot fuel screws are on the bottom at the front of the bowls. Set them 2 - 2.5 turns out from lightly seated.

15 pilots are stock. Go with them to start. If still lean on the bottom after you lift the needles to 4th groove, try going 3 turns out on pilot fuel screws. If still too lean, go with 17.5 pilots. They are the long pilot type in those carbs. Not like the early carbs or the 29 smoothbores.

Needles will be 5CN19 with clip on 3rd groove, lift to 4th groove. Don't loose the plastic washers or the springs inside the slide when you take them apart.

120 Main Jet will get you in the ballpark there.

That should get you up and very roadworthy. Fine adjustment from there will depend on the health of the motor.

Larry C

thanks larry,ill try it.

o larry,i did remove pump rod.you know where it should be set,i have the little nut tured on about a 1/8'' on.

b.tracy79kz wrote:

o larry,i did remove pump rod.you know where it should be set,i have the little nut tured on about a 1/8'' on.

Sounds about right. I'll check my OEM Manual. There's a spec in there for it. In the meanwhile, proceed and you should have good results.

I found the V&H pipes were always fussier than Kerker pipes on KZ motors. Have V&H on my presently and I like it a lot. Nice sound, looks good. Had to dink with it to get the fit correct but I would not hessitate to suggest V&H pipe on a KZ...

Forgot to mention. Check the fuel level in each bowl. Not float height but the actual fuel level. That's got to be correct before you can nail the jetting down.

Larry C

Larry, would you suggest the same 26mm carb settings for a stock KZ900 with pipe and pods?

EricHa wrote:

Larry, would you suggest the same 26mm carb settings for a stock KZ900 with pipe and pods?

While I would defer to Larry C., will say the '76 Mik 26mm mech slide carbs are probably the most user friendly carbs around, and serve well in a variety of tuning applications.
I run oem 26's in 76KZ900-B1 LTD with 1015 cc, K&N in stock air box, and free breathing Kerker, all with excellent performance from the oem carbs, which may if necessary be jetted to accomodate the engine mods, but often unnecessary.
Pulls hard and even from idle through redline, jet needle clip in mid-position, plugs nice and dark tan.

Good Fortune!

Thanks Patton. I may have 117.5 mains instead of 120's in my VM26's. I'll have to check. I was going to run VM28's with Andrews 2X cams in this project, but scored another KZ900, so I may just run the stock carbs and cams.

I see that you have a GB. My brother has one of those little thumpers. He just got a 1976 CB400F as well. Fun little four!