CARB Needed

i am looking for i 29mm smoothbore carb for a 78 kz 1000. One of my jetblocks are stripped out and i only need that part but will buy the whole carb.

still needing this carb

I have a set of spare kz650 carbs, not sure if they are the same or not. PM me if you think they might work. I could take pics if needed.

i still need a jetblock

look in the classified parts section. i have 2 i'll sell you for 200

keithnra wrote:

i am looking for i 29mm smoothbore carb for a 78 kz 1000. One of my jetblocks are stripped out and i only need that part but will buy the whole carb.

One of my jetblocks are stripped out -- does this mean only that the small threaded hole in the bottom of the jet block is stripped, or something more serious?

The little screw going into the small threaded hole in the bottom of the jet block is mostly for positioning the jet block in correct orientation inside the bore and also holding the thin paper gasket in the correct position (if I'm remembering correctly).

The little screw is not intended to tightly hold the jet block against the bottom of the bore. If over-tightened (meaning tightened much at all), the jet block becomes slightly tilted (like the Leaning Tower of Pizza) and begins scraping against the throttle slides (not a good thing). Note that the screw hole is not centered in the jet block bottom.

Am wondering if a tiny dab of JBWeld into the stripped hole could afford enough grip whereby the little screw could hold the jet block in place without hardly any tightening at all.

Seems there would be no harm in trying. When found, a new replacement jet block is very expensive.

Good Luck!

P.S. Am trying to add some info about a possible source, if not already known.

Ian Williams Tuning (Australia) lists this part (also called Venturi Block)

002-500
VM29/10 JET BLOCK
$120.00

Website
Ian Williams Tuning

Contact info
Email, etc.

Have never dealt with them, but it's an interesting website with some good info and parts diagrams.

www.iwt.com.au/mikparts2.htm

www.iwt.com.au/

Patton, A stripped jetblock means that the jet block thread where the needle jet screws into it is stripped. This is common. The needle jet is about 1 1/2" long and goes through the main jet well and carb body and screws into what this fella is calling the jetblock. The jetblock is fitted into the venturi and the part that is threaded fits into a corresponding hole in the base of the venturi. The jetblock is held in place by a M3 x 6mm long screw in base of the carburetor. Once you remove the jet block, there is a very thin gasket between the venturi and jetblock that needs to be replaced most of the time because the carb won't idle right without it. You can't make a new gasket very well as it is very thin and hard to do.

My company is attempting to figure out a way to repair stripped jet blocks. Will make an announcement if we figure this out. One of the problems is lack of material for an insert and the insert will need to have unusual thread pitch which you just can't buy off the shelf somewhere.

The problem is caused because the thread is very shallow and there isn't much thread and if the needle jet is overtightened a bit, the thread will just let go. There isn't much money to be made repairing the things due to low volume of the carburetor type but there are a LOT of smoothbores out there that could use this repair.

You CAN fix the problem by JB Welding the needle jet in place. You just wouldn't be able to remove it again and I don't think that is a great way to repair the problem.

i have found a good jetblock for my 29mm smoothbores, does anyone know what type of gasket paper is used for the jetblock or know anywhere i can get a gasket from, i am almost ready to get these smoothbores on my bike. if anyone knows the dimensions of the paper i think i could makeit.

You can't make a gasket that goes under the jet block. It is too thin and you will end up with the jet block not fitting correctly. These gaskets are now available from www.z1enterprises.com - I am sure you will need to call them as I doubt it is in their on-line catalog. wg

Z1 has these gaskets for like 2 bucks.

FWIW,I did make my own gaskets when I first got my 29's,about 3-4 years ago now(can't remember exactly),and they're still working.
The only reason I DIDN'T buy new ones,is because at that time,they weren't available,even through Sudco.
I do plan on getting a set of factory ones,so the next time I have to pull the carbs apart,I'll be able to replace them with nice new ones.(yippee)
I made them out of writing-paper...soaked the paper in oil first, and used one of the originals to trace and cut from.
Like I said...at least 3 seasons now,and no problems.
But hey...if they're available,get them.Don't go through the hassles that I had to.

finally got all the parts needed, thanks keith