Where to find Carb Kits

I drive...well fix for now a 80' KZ750G1. For the life of me, I can find the stupid carb kits anywhere for this bike. The Bike has been sitting at my father in laws place for 16 years...has not ran since that long ago. So as you can tell, I have LOTS AND LOTS to do on it before it is road worthy again. I have been successful in actually taking the carbs apart and cleaning them up with just a toothbrush, and some gas just to clean all the gunk out of it. I got a new battery and to my surpize the thing started up. However, it does run a little rough at idle. Now I am not sure if the timing is off...I am pretty sure it is though since I know my brother in law tried to get it running a while back and ended up messing with the points and hosed it by putting the lead to the coil on backwards causing it to ALWAYS be grounded. Obviously because of that, he never would have gotten it to start. I am getting the manual for this bike but am getting kind of anxious to get it running so hopefully I can find someone on here that has some good knowledge with this bike. I guess the first few questions are:

1. Where can I find the dang carb kits?
2. Is there adjustment screws somewhere and if so, how should they be set. (I ask this because for the life of me I cant find anywhere to adjust these things except for the sync.

3. Prob need to be asked in the Electrical section, but how in hell do I adjust the timing correctly on this? The under the seat it gives me instructions about setting the F mark with the ignition mark, but I dont see either. All I have is this, and as you can see I dont think it is right since the plate is turned ALL the way to one side.

I don't know for sure but I think the F mark will show up in that hole on the points plate if you rotate your engine a bit. It should be stamped on the advancer mechanism. The other mark is in the hole also, right below the top screw on the points plate.

I don't know on your carb question.

You got it to run... fantastic and congrats. Great to see an old bike being resurrected.

Ditto to what aarons80kz650 said.

I don't have your type of bike but I and many members here get our carb kits from Jeff at Z1 Enterprises... good prices, fast shipping and outstanding service. I found your bike listed here:

www.z1enterprises.com/catalog.aspx?pid=KZ750-G1-1980-CF0

Hmmm, I did not see a carb kit but they have more than what is shown on the site... so send them an email at:

parts@z1enterprises.com

Best of success.

PS
Could you add your year, model and location directly to your signature. It will help members respond better... and it is considered very friendly too.
Bill

Good luck finding a carb kit for a 1980 KZ750G

I looked for a year, plenty of kits available for the 76-79 KZ750B, but none listed anywhere (that I ever found anyway) for the 80G.

Strange, in that 76-79 uses Mikuni BS38 carbs, and the 80G uses BS38 carbs, you'd think the parts kits would be the same.

PM a member by the name of WiredGeorge, he knows a bit about carbs, at least if he can remember it, being over the hill and everything

www.wgcarbs.com is his website, and he has a forum there that he checks more often than he does this one.

steell wrote:

Good luck finding a carb kit for a 1980 KZ750G

I looked for a year, plenty of kits available for the 76-79 KZ750B, but none listed anywhere (that I ever found anyway) for the 80G.

Strange, in that 76-79 uses Mikuni BS38 carbs, and the 80G uses BS38 carbs, you'd think the parts kits would be the same.

Is it possible the kits for the B models are the right ones but they just don't list the G model?

Anybody ever go to the kawi explosion drawings and see if the part numbers for the pieces in the carbs are the same?

Very interesting find...the part numbers are different but they appear to look exactly the same. I might have to go look into this...

In any case...here is my update.

I was having a problem getting it running earlier so I took the advise of the above people for getting it timed and now that is right on however it was still not starting. I took the carbs down again and cleaned them all out again...still waiting to find the right kit. Luckily it started this time, HOWEVER it only runs in choke and once I give it just a hair of gas it dies. It will bump start and idle just like I want it to, but if I try to move it out of choke, even warmed up or try to give it any throttle it dies. Does anyone know what could be causing this? I dont think I missed anything putting them back together.

Probably a serious vacuum leak, or maybe not enough fuel to the carbs, or possibly service fuel level (level of fuel in the float bowl) to low.


I tried using 76-79 carb kits in 80G carbs, never could get it to run right, took the kits out of the 80G carbs and installed them in 79 carbs and the bike ran perfect.

I think WG told me what the difference was one time, but then CRS kicked in

All VM26s are NOT the same. All VM28s are NOT the same and so the same can be said of the BS38:

Type BS38 1976-1979
Main jet 125
Main Air Jet 1.0
Needle Jet Badge # Z-4 or Z-4
Jet Needle 4JN19-4 or 4HL12-3
Pilot Jet 45 or 40
Pilot Screw 11/2 + - 1/2t turns out
Starter Jet 110
Fuel level (from bore center) 31 ± 1 mm
Fuel Level 4.5mm ~ 6.5mm

BS38 1980 KZ750B4 and 1980 KZ750G1 models
Main jet, 125
Needle Jet Badge Y3,
Needle Jet 4HL14
Pilot Jet 40
starter jet 45
Service Fuel and Design Fuel Level the same, pilot screw -blank
main air jet 1.0

Note the difference in the needle jet/jet needle combo? If you used everything from the 76-79 KZ750B kit in a G EXCEPT the jet needle and just retained the old jet needle, the kit will work fine. It includes the dainty little main jet and a #40 pilot jet and mix screw and bowl gasket so you should be FINE. Just don't use the jet needle on a KZ750G. Needle jets have a badge designation and the designation indicates the size. There are 10 sizes in the Y range which is smaller than the 10 sizes in the Z range so as you will note in the specs I posted, there are the B needle jet is 11 sizes larger than a G so the jet needle MUST be matched. On other carb sets this may not be the case when the size differential is only a couple of sizes.

wiredgeorge wrote:

All VM26s are NOT the same. All VM28s are NOT the same and so the same can be said of the BS38:

Type BS38 1976-1979
Main jet 125
Main Air Jet 1.0
Needle Jet Badge # Z-4 or Z-4
Jet Needle 4JN19-4 or 4HL12-3
Pilot Jet 45 or 40
Pilot Screw 11/2 + - 1/2t turns out
Starter Jet 110
Fuel level (from bore center) 31 ± 1 mm
Fuel Level 4.5mm ~ 6.5mm

BS38 1980 KZ750B4 and 1980 KZ750G1 models
Main jet, 125
Needle Jet Badge Y3,
Needle Jet 4HL14
Pilot Jet 40
starter jet 45
Service Fuel and Design Fuel Level the same, pilot screw -blank
main air jet 1.0

Note the difference in the needle jet/jet needle combo? If you used everything from the 76-79 KZ750B kit in a G EXCEPT the jet needle and just retained the old jet needle, the kit will work fine. It includes the dainty little main jet and a #40 pilot jet and mix screw and bowl gasket so you should be FINE. Just don't use the jet needle on a KZ750G. Needle jets have a badge designation and the designation indicates the size. There are 10 sizes in the Y range which is smaller than the 10 sizes in the Z range so as you will note in the specs I posted, there are the B needle jet is 11 sizes larger than a G so the jet needle MUST be matched. On other carb sets this may not be the case when the size differential is only a couple of sizes.

On the topic of needles: my 1979 KZ750 B4 has the stock BS-38's. When I bought the Keyster rebuild kits allegedly for this engine and carbs, the kit needles did not match the stock needles. The Keyster kit needles are about 1/8" shorter than stock, but can be installed in the carbs (obviously will run much richer). I believe if you use the kit needles at the leanest clip position (top slot) they would be pretty close to stock.

Great...thanks for the info guys. However, I found my problem. The problem was as simple as just cranking up the idle speed and then not putting the choke on all the way when cold. Apparently it is warm enough here that I dont really even need the choke at all. I am not sure why the dang thing even ran when I had it in full choke. But as soon as I idled up and lets the butterfly's open a little and then cut the choke. It fired up just fine and ran great. Now all I have left before I can ride is tires, chain and sprockets.
:woohoo: