Bent jet needle

I recently acquired a 1977 kz1000 A1. It was not running. The carbs were all stuck solid like someone painted all the parts with varnish, assembled them, and then left it sit for 10 years.

I cleaned and reassembled, set floats, and reinstalled them. Set the points and timing. VROOM! she fired right up. Synchronized them. Didn't idle too well, but went OK when revs were up. Sparks were all OK. 125-130 psi all across. Number 4 exhaust pipe was cold at idle.

Suspected pilot circuit so I took off the carbs again. Now this is the bad part. I dropped one of the slides with needle on the concrete floor and the needle bent about 1/4 inch from the point.

I've straightened it as best I could.

Should I get a new one, or would it be OK to reuse it?

Galactica wrote:

I recently acquired a 1977 kz1000 A1. It was not running. The carbs were all stuck solid like someone painted all the parts with varnish, assembled them, and then left it sit for 10 years.

I cleaned and reassembled, set floats, and reinstalled them. Set the points and timing. VROOM! she fired right up. Synchronized them. Didn't idle too well, but went OK when revs were up. Sparks were all OK. 125-130 psi all across. Number 4 exhaust pipe was cold at idle.

Suspected pilot circuit so I took off the carbs again. Now this is the bad part. I dropped one of the slides with needle on the concrete floor and the needle bent about 1/4 inch from the point.

I've straightened it as best I could.

Should I get a new one, or would it be OK to reuse it?

Get the number off the needle. I might have one. If I do, I'll pm you for your address and throw it in the mail.

Larry C

needs replaced....i d bet 50 bucks its whatever the manual says is the stock needle.......

yea i got a few layin around too if Larry cant help

My eyes aren't too good any more, but I think the number on the needle is:

5CN8

I believe the bike is 100% stock. It's in pretty good shape. The tank is out right now getting stripped inside and out down to bare metal. I'll get it, and the panels repainted the stock red with gold stripes. Of course it needs all the maintenance stuff, like wheel bearings, steering head, sprockets, chain, seat, chain guard, mirror, etc.. But the motor is really strong, and all the chrome is really good too, and the tock exhaust is excellent.

Thanks in advance if you have a needle.

R

Galactica wrote:

...1977 kz1000 A1...Didn't idle too well, but went OK when revs were up. Sparks were all OK. 125-130 psi all across. Number 4 exhaust pipe was cold at idle.
Suspected pilot circuit so I took off the carbs again. Now this is the bad part. I dropped one of the slides with needle on the concrete floor and the needle bent about 1/4 inch from the point.
I've straightened it as best I could.
Should I get a new one, or would it be OK to reuse it?

...Suspected pilot circuit.... Me too.
Especially on cylinder #4, which isn't combusting.

And the jet needle has virtually zero influence on idle performance.

Good Fortune!

Galactica wrote:

My eyes aren't too good any more, but I think the number on the needle is:

5CN8

I believe the bike is 100% stock. It's in pretty good shape. The tank is out right now getting stripped inside and out down to bare metal. I'll get it, and the panels repainted the stock red with gold stripes. Of course it needs all the maintenance stuff, like wheel bearings, steering head, sprockets, chain, seat, chain guard, mirror, etc.. But the motor is really strong, and all the chrome is really good too, and the tock exhaust is excellent.

Thanks in advance if you have a needle.

R

I'll check today.

Galactica wrote:

My eyes aren't too good any more, but I think the number on the needle is: 5CN8
I believe the bike is 100% stock.

Yes --- Per FSM, 5CN8 is correct jet needle for stock Mikuni VM26SS.

Good Fortune!

Thanks guys. I have purchased a FSM on ebay from Denmark. It will probably take a month or so to get here. The ones I saw on this side of the Atlantic looked like crap.

I understand that the jet needle has no bearing on the idle. The problem is that it got bent, and although I straightened it, it is not perfect. I suppose it is possible that, as it rises and falls, the cross section of it may be affected and not meter the fuel precisely enough.

I've left the #4 carb and pilot jet soaking overnight in Seafoam. I'm heading out to the garage now. I'll blow it out, give it a shot of carb cleaner and blow it out again. When I get a replacement needle I'll let you guys know the results.

The plan is to do a fairly good job on this bike without taking out the motor. Then I'll ride it while I do a frame off resto on my 900.

Cheers,

R

Does any one have 5CN8 jet needle the would be willing to part with? It would be greatly appreciated. If so, shoot me a PM.

Cheers,

R