Carb Advice

So I want some opinions or advice on the engine build on my '76 KZ900. The motor has 59,xxx miles on it, so I am going to start with a fresh rebuild and most likely a bore job. I will most likely do a 1015 big bore kit, bump the compression up, Dynatech Ignition, full exhaust, pods, and possibly a camshaft with adjustable timing gears. It will have all the supporting upgrades as well (valve springs, timing chain, studs, wleded crank, etc...) So my questions are:

1. What are the power and engine limitations on running a tuned set of VM26's that were on the bike? What are the benefits?
2. Is converting to the later BS34's worth the money and effort? What are their limitations?

I wouldn't mind giving up some top end power for a smooth and torquey powerband. I kinda like the thought of a mechanical carb instead of a diaphragm. Thoughts?

Cory

VM28's from a KZ1000 would be a lot better than the BS34's. Or a set of Keihin CR29's if you have the cash for that.

No eBay APP ID and/or Cert ID defined in Kunena configurationNo eBay APP ID and/or Cert ID defined in Kunena configurationHere are some 28mm Mikuni's, 29's would be a nice touch to the motor if you can even find a set.





Here is a set of "Pumpers"

I have almost every Kawi Mikuni carb set on EBay on my watch list. So the VM28's or Smoothbore 29's are what people are recommending?

Cory

29s would be best, followed by 28s. Your 26s will seem weak up high, but do pull well from a dead dig up to about 70mph. But dont recommend 26s with a modified engine. I think WG carbs can bore out your 26s if so desired

Bored out stockers might be a way to do it... Has anyone tried CVK36's from a Kawi ZRX1100? I have a ZRX and wonder if the carb spacing is the same? Thoughts?

Cory

NakedFun wrote: Has anyone tried CVK36's from a Kawi ZRX1100? I have a ZRX and wonder if the carb spacing is the same? Thoughts?

Cory

The ZRX uses a side camchain setup while the old Kaws use a center camchain setup. The spacing will be close to equal on the ZRX carbs but the KZ carbs will be paired left and right....if that makes sense.

Later, Doug

I wouldn't go teh boring route. Much cheaper/easier to get a set of 28's.

T_Dub wrote: I wouldn't go teh boring route. Much cheaper/easier to get a set of 28's.

X2

VM29's may be a risky buy on ebay. many will be worn out or have toublesome parts.

I would put a set of Mikuni RS34's on your ebay list as well. if u come across a set, they will work well. some will say they r too big, but lots of guys r using them om KZ810"s.

I am interested in the boring out of the VM26's. Since they will probable need a rebuild anyway, instead of buying extra carbs, have them taken out a bit. I have looked at the radial side 34's, but they are on the expensive side of things for a carb that may be a little on the sloppy side of responsive with the potential engine combination I am planning.

Yeah I figured the side chain vs. center chain of the KZ woud play a role in the carb spacing, but didn't know how much. I should actually measure it up tonight and see. Those carbs are plentiful and easily modded.

I'll keep my eyes open for a decent deal...

Cory

personaly, i think if u want to gain performance, boring a carb is a bad move.
u just end up with a bigger carb, not a better carb. a 28 pumper would be a better choice than boring.
there is a reason that smoothbores perform better, and it is not because they r bigger.
u can find used rs34's for less money than $530 for bored carbs. and the rs34's will work better.

Just my opinion.

From Georges website "works as well as a VM29 smoothbore WITHOUT the high price"


I am with Mark on this one. Works as well I doubt it, Sales and Marketing is what it sounds like to me. $539 is on the expensive side to me. Just saying