looking for a carb

[b1pig]

Anyone have a carb they want to part with for cheap? My wife's bike will NOT run off idle.... getting sick of the on/off game with it. Looking for another one to clean and put on it.

[derbydave]

Have you tried rebuilding the current carb? They are really easy and cheap to rebuild

[b1pig]

I've had that thing apart numerous times. Last summer, I had that sucker running like a champ. The idle was a little unsteady... I thought it may be related to an improperly set float level. Wife rode it to her "job" which is about a 25 mile one way ride. 7 miles from home, she was coasting/downshifting to a stop sign from 60mph and when she pulled the clutch in, it died and would not restart.

After I trailered it home, I put the petcock on Prime and it started up. PERFECT idle, but any throttle kills it. Won't run above ... uh... just off-idle. However, if I pull the enrichment, the engine speed comes up. Twist the throttle, it chokes off. It SEEMS to me that the idle circuit is clear, but the circuit(s) covering midrange will not flow fuel. So far as I know, if it unscrews from the carb, I've removed it, cleaned it, soaked it, scrubbed it and sprayed it.

I don't have the money... and this little bike isn't really worth the cost to me... but I've been thinking about just buying one of those 28mm fuel injection conversion kits.

I just don't have the room to take it apart and leave it apart while I soak it for days in solvent. Thinking I might just have to roll it out on the back porch from the garage and put it under a tarp for a couple of weeks while I tinker with it and let is soak in... things.

[derbydave]

When you had it apart did you replace the seals and O-rings? How is the diaphragm for the slide? If it has any holes or is torn it won't run right.

[blaine]

When you cant get it to rev without choke is most times a Idle circuit/mixture screw problem......How many turns do you have the idle mixture screw turned out?

[b1pig]

The idle is perfect.
Once warm, "choke" can be turned off. Slow application of throttle will increase RPM slightly... by a couple hundred, then it begins to miss. Starving for fuel. Pull the choke and the RPM climbs progressively with the choke lever. Additional application of throttle will again increase RPM slightly until it begins to miss and or/falls off. Rapid open/closing of throttle can get the RPM up significantly higher, but not reliably.

Its NOT the idle circuit. I did wonder if the slide is not coming up. The diaphragm appears fine. No damage. No holes. No stretches or wrinkles. The bike is fully together. I tried to pull the airbox out of this thing once and I as I recall it was a complete PITA. Obviously I was missing something.... or maybe it will only come out if the engine is out. (???)

[derbydave]

The carb will come off without pulling the air box or engine. Did you replace any of the seals and o-rings? It sounds like an air leak, or blocked passage in the carb body.

[b1pig]

Believe me, I have the carb removal/installation perfected to a science.... I spend more time getting the tools out and the bike positioned to to the job than actually working.


Video for reference
https://youtu.be/FJlz_VJ1zXI

I realize this “parts wanted” thread has morphed into a troubleshooting thread if any moderator wants to move it to the appropriate forum..... 🤣

Not that I don’t appreciate the effort, guys.
I’ve removed the carb NUMEROUS times. If you check my forum activity, I’m sure it will be reflected in the threads/posts. The only things I have NOT tried are soaking/heating in lemon juice or PineSol.... both seemingly popular internet fixes for crappy carbs. I soaked it for a couple of days in that Berryman’s stuff a couple of years ago. Since then, it had a weird idle that would creep up if the bike sat with the engine at idle.

In ref to o-rings.... the only one I changed was the one I think on the pilot jet? Did that one a couple of years ago. Really no issue with it at this point. Still pliable with no cracks. I mean seriously. This thing is CLEAN. I’m kinda convinced the midrange fuel/air tracks are plugged. The day it started this was a sudden onset last summer. Now the wife won’t trust the little **** past the front yard. Meaning she won’t ride it. Not that I blame her.


Sent from my iPhone using Tapatalk

[derbydave]

It sure sounds like it is starving for fuel. The blued exhaust pipes even indicate running lean. How is the petcock? have you tried running it in the prime position?

[Vegas Street Rider]

I would check the petcock and make sure the vacuum hose on the back side of it is good and snug just for starters. Like Derby Dave mentioned, try running it on the prime setting. If that checks out, you might even want to pull it out and check the inlet screens to make sure something didn't slough off from inside the tank and plug the screens.

[b1pig]

Yea, it was running on prime in that video. The blued pipes are from an earlier incident a few years ago.... That was what started this whole thing. After I took the carb off and cleaned it the first time, I turned the idle mixture screw out a little and enriched the mixture. That cleaned up most of the engine's bad habits. Wife rode it quite a bit around that time. Only issue it had THEN was the idle was kind of erratic and would creep up on you. Which it doesn't do now at all. As a matter of fact, the idle is dead steady.

If I had the $700 or so to swap in a fuel injection kit, I'd do it.

[derbydave]

If It was me I would completely tear down and clean the carb and install a complete carb rebuild kit like this one.

https://www.allballsracing.com/26-1659.html

[b1pig]

I fixed it......


Removed it this evening. Completely disassembled it again. Took good care to lookat EVERYTHING as I took it apart. The silver collar that goes above the main jet holder was upside down. Last time I assembled it, I did it off memory. The collar would not go into the hole no matter how I tried, so I figured I had it upside down. Flipped it and dropped it in and it fell right into place like it was meant to be that way.

That silver collar... the FLAT side goes towards the bowl and the side with the tapered internal goes up towards the bore. When in doubt, refer to the dang manual. I STILL could not get the collar in. Dropped the slide/needle in from the top and held it in place as I held the carb upside down.... dropped the collar in... still didn't drop in. BUT. Once I threaded the main jet holder in, it fell right in to place. Revs good. Idles perfect. Probably the cleanest Mikuni on an 11 year old bike.

I am amazed that the collar just being upside down was the only dang thing that I found wrong and it was this serious.

[GWIFF]

I know this thread is a year old, but I am having almost the same exact problem, is there any way you could post some photos or more explanation of exactly what silver collar you are talking about ?

[b1pig]

replied to your PM.

let me know if you need anything else.

[b1pig]

..... and its clogged up again after sitting for a few months... and after the carb was drained.

i hate this thing.....

[Vegas Street Rider]

Are you treating your fuel with anything when it sits idle for some time b1pig? I usually run Seafoam through the system before I store the bike for any time. If there is fuel in the tank, I also add Stabil to the fuel so it doesn't go bad.

[b1pig]

I got a new ultrasonic cleaner. Removed and disassembled the carb (again) and dropped it into the new cleaner along with a nice mix with some Mean Green... three 5 minute cycles in the cleaner.

Put it back together and its running great.

I keep Sta-bil in this bike. I also try to keep nonethanol fuel in it. There are a couple of stations that have "marine" gas at the pumps. That, and any time I know the bike it going to sit more than a couple of weeks, I drain the carb, disco the vacuum line and try to make sure the carb is as dry as it can get.

I'd rather put a non-vacuum petcock on it so I can cut it off and let the carb idle it dry. I have done this with every other motorcycle I've owned and had zero issues with the carbs fouling up like this thing.

The wife just doesn't want me to change anything on it. Also, she has told me three times to sell it, and every time I clean it up and get it running right again, she rides it a few times and changes her mind. LOL

[Vegas Street Rider]

Sounds like you go above and beyond in the maintenance department. The only other things I would look at is if the fuel tank has some built in sediment in it or the filter screen on the petcock is damaged causing gunk to leak through to the carb.

Not wanting to stick my nose in your business, but maybe your wife wants a different bike. Just sayin.

[b1pig]

She did. We tried. Honestly, I think after her back surgery she's done... with the exception of the occasional jaunt on the GZ.

I have a feeling it will be on sale again soon. We have too much going on right now. It's a bad time for a lot of people. We've got our fair share of less than happy stuff, so....

It's all good.

Thanks for keepin the traffic goin on the forum. Forums are a dying form of chatter and information exchange. I have been a moderator on another forum, and its been a ghost town for a few years. We still keep it up and running. The archive of info on there is an asset to people who need to do research on Jeeps.

[Vegas Street Rider]

Things are pretty tough in the Vegas valley too for a lot of people. Not a good time to be selling things as all the websites like Craigslist, Offer Up, and others are glutted with things people can't seem to give away.

As for the forum traffic, things have really slowed down here. I help within the realm of my expertise which is not very deep. I usually try to share what I do know and the issues I have had with my bike, but beyond that some things are just over my head.

Many of the original members here have either upsized to another bike or have quit riding altogether. Being that the production of the GZ stopped in, I believe, 2010, those that are acquiring these bikes are converting them into cafe racers or rat bikes. I will keep mine stock as the style fits me and is the perfect ride for me at this time in my life.

I hope your wife's back heals and maybe tries to get back to riding. I have back issues too and it can be overwhelming sometimes. I just can't give it up yet after 56 years in the saddle.