TOPIC:

Hey guys. I am hoping to get some help here. I am looking at a carb that seems to be for my model bt it looks a little different than mine.

Compared to my carbs and another bank I bought for my bike, on the one I show below are 2 things different.

- The float looks different. But I guess that doesn't make any difference.

- What really interests me is the fact that those carbs don't seem to have any screw to adjust the idle mix. Im not sure if there is something inside there that is in a fixed position but how would I be able to adjust that or clean? Doesn't seem to have any opening where it usually is:

Hi
They look like the Keihin CV34 carbs that are on my bike and which I believe are stock on the 81. There'snot much of the float bowl showing in the pictures but from what I can see it looks right.

The mixture screws are covered by a metal cap or plug. We didn't have those caps in Canada but from what I read here they can be removed by carefully drilling to maybe 1/8 of an inch and screwing in a self taping metal screw and pull up and out. Careful not to bugger the head of the screw underneath.

The idle speed screw/knob is underneath and looks to be there if you enlarge the first pic. I edited your pic to show the above.




If you can post a picture of your current carbs we might be able to identify them. Possibly Mikuni BS 34 from a later model

why would they cover it and make it so difficult to access? i remember buying one similar one and we couldn't get it running because i couldn't access the screws or didn't even knew what was going on inside there.

the floats look more square compared to the regular ones i know and the ones i had in 3 banks which are more roundish. anyways that doesn't matter. but the thing with those screws is just weird to me. the fact that they have to be drilled open.

I believe the Caps were there because of the US emissions thing and people were prevented from adjusting the mixture. . In Canada and the rest of the world we didn't have that snorkel type mess of tubing under the tank between the head carbs and air box either. Many in the US removed that stuff.

JR is correct --- EPA reg stuff. Not only did they not want you messing with them, but the manual may not have adjustment info. It may not matter, but before messing with them, turn them in until they just seat, counting the number of turns, then remove them. Jot down the numbers. You may find that they are all over the place, which seems to be fairly common.

What is wrong with your current carbs? Those look well used and rusty. Are they even for your bike? If not year specific, you may be buying more trouble that they're worth. Those are CV carbs. When they work, they work well. Tolerant of altitude changes, good on gas etc. Not the hot setup for HP though and rebuilding them means $$$. Be careful.
Steve

Yeah that makes total sense. No, I won't buy them. Too much trouble like that.

So do your carbs work?

He already has his carbs for sale, I believe he said he's "upgrading" or something, too lazy to check but I believe he said it 'starts so easy he removed the chokes' which IMHO means its jetted too rich.

swest wrote: So do your carbs work?

He already has his carbs for sale, I believe he said he's "upgrading" or something, too lazy to check but I believe he said it 'starts so easy he removed the chokes' which IMHO means its jetted too rich.

Yes they work. I want them for a new project. But I found something better. Little more pricey but better and with the idle mixture screws.

They are not too rich and thats not the bank thats for sale. They are both perfect set up. Sparks are in the ideal range.

floivanus wrote: He already has his carbs for sale, I believe he said he's "upgrading" or something, too lazy to check but I believe he said it 'starts so easy he removed the chokes' which IMHO means its jetted too rich.

If it's jetted too rich, he can be "washing out" the rings. I'm still trying to find that "sweet spot" where I need the choke and still have the power across the RPM range. This is where it gets complicated, throttle cutaway, nossel and needle size, etc.
"Lean is mean".
Steve

You just remove the plugs and then you can adjust the idle mixture. It's not a big deal. You do need to make sure the small o-rings that seal the adjuster screws are good and not leaking. You'll find that those idle mixture screws don't make a big difference in the tuning though. On my 81 kz1000 they are out about 3.5 turns. The most important thing is to get the 4 carbs synchronized properly and the engine will run nicely as long as you have good compression and no cylinder leakage. Of course the carbs need to be clean and the ignition system working properly.