Big Sigh......input needed

[azr]

If you don't have a vacuum gauge to do the vacuum synch then the only other thing you can do is a bench synch, a very good, accurate bench synch. This could be your problem, there is so little vacuum being pulled on #3 it's not firing properly?? that makes sense why playing with the mixture screw makes no difference. Pull them off and do the bench synch.

[520eek]

Where would i find the procedures for doing this bench sync? I will try looking around in the carb forum and see what I can come up with.

[jsandidge]

youtube

Where would i find the procedures for doing this bench sync? I will try looking around in the carb forum and see what I can come up with.

There are a few videos on youtube showing it done. Search for mrmaxstorey. I don't recommend his method of cleaning, it's not a strip and dip. But the bench synch he does is ok.

[Nessism]

Bench sync is just to get the engine running. I don't even bother with this most the time. Set the pilot screws at 2.5 to 3 turns, get the engine running, then vacuum sync. and tweak the pilot screws at the same time. Put a fan in front of the engine so you don't overheat the thing. Sometimes the engine speed doesn't change when you tweak the pilot screws and this is okay. Just make sure the total number of turns open is in the same range as the other cylinders.

[520eek]

So....I read that people leave a carb in the berryman dip for a day, then clean. I would guess I would do that as well if it had barnacles in the bowls or nastified looking stuff. The bike I got ran okay, but I decided to dip/clean them anyway so I would have a good baseline. Now I figured a brand new can of this stuff should work wonders. I dipped each carb about 20 minutes, cleaned and assembled, and installed on bike. There was the problem on #3 so I tried to swap things around a bit but to no help. Problem stayed with #3.

Off came the carbs again and I stripped and soaked #3 only and this time it was in for about 2.5 hours. Cleaned and assembled. I have read through bench sync now and apparently I had done that. I wanted to see how things worked and got it to where a sliver of light was all that was showing for my bench sync. I just wanted the bike to fire up and get running at a reasonably close setup.

So far..as you can tell by my posts. The #3 cylinder is seemingly corrupt by a failed idle circuit in carb. How long is to long for a soak in the berrymans carb cleaner? Are there o-rings on the throttle shaft that I should be concerned about if I leave carb in dip to long?

I plan to get #3 off the bike and start to soak overnight...or longer? Any other thoughts?

I do like the idea of comparing another carb to this one as I go about this cleaning process, so that will be something I can do easily and have results that will prove things one way or another.

[Big T]

Hmm

I have to guess, but I would say you either never got a Megawelcome, or you didn't read it

All carb mysteries are solved there

http://www.mtsac.edu/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

also, you're spending more effort trying for the easy way. Go down the list and see what you can check off

http://www.thegsresources.com/_forum/showthread.php?t=171846

[Gorminrider]

yes, have a look there.

A dirty main jet will also cause a cold cylinder- ...on the cv type carbs I have, those tiny holes in it got plugged with corrosion ...

With a carburetor issue, I can only be happy if I know these are ok.
If you haven't already,see if you can get them out per the tutorial that applies to your carbs without wrecking them. If they don't come out"properly" with safe persuasions, that would also be an indication of corrosion and you will have to find some magic liquid to do it. I don't know what that is, because mine came out and I was able to work on em ok.
and then there's the valves...vacuum passages only work where vacuum exists

[520eek]

Well....I pulled the carbs and I can see that my bench sync by eye wasn't very good. Perhaps I moved the sync screw on bike the wrong way one to many times...But, thanks to the miracle of internet and paper clips, I have what I believe to be a much better bench synced set of carbs.

I was going to strip it down but it is so clean and I checked passageways and compared to #4. I just figured this might be the ticket. It was fairly clean to begin with bit did a dip and replaced o-rings, diaphragms just so I would know that it was done.

Stay tuned as I go out in the garage to install.....

[520eek]

Yea!!! Put the carbs on and got it all together and fired it up....and its worse! F**k this. I am getting quite good at taking carbs off and putting back on..... now 1 and 2 wont fire at idle...swapping wires does not help. Squirting brake cleaner around carbs and boots reveals no air leaks. Looks like at this point trip is now a done deal for a no go and I hope it rains. At least I will have plenty of time to bang my head against a wall!! Aarrgh...

[520eek]

Update...made appointment for local independent to sync carbs ( and get another pair of eyes on it ).

Number 3 would not respond to idle mixture, nor would #4. Bench sync was pretty close though. Wound up getting a used set of carbs that seem to be period/model correct. I have stripped them down and dipped them and that is as far as I have gotten. Hopefully this will clean up my idle and I can move on to other things.

Any thoughts on rerouting crankcase breather out of airbox and into something specifically for that only?

[mrbill5491]

So....I read that people leave a carb in the berryman dip for a day, then clean. I would guess I would do that as well if it had barnacles in the bowls or nastified looking stuff. The bike I got ran okay, but I decided to dip/clean them anyway so I would have a good baseline. Now I figured a brand new can of this stuff should work wonders. I dipped each carb about 20 minutes, cleaned and assembled, and installed on bike. There was the problem on #3 so I tried to swap things around a bit but to no help. Problem stayed with #3.

Off came the carbs again and I stripped and soaked #3 only and this time it was in for about 2.5 hours. Cleaned and assembled. I have read through bench sync now and apparently I had done that. I wanted to see how things worked and got it to where a sliver of light was all that was showing for my bench sync. I just wanted the bike to fire up and get running at a reasonably close setup.

So far..as you can tell by my posts. The #3 cylinder is seemingly corrupt by a failed idle circuit in carb. How long is to long for a soak in the berrymans carb cleaner? Are there o-rings on the throttle shaft that I should be concerned about if I leave carb in dip to long?

I plan to get #3 off the bike and start to soak overnight...or longer? Any other thoughts?

I do like the idea of comparing another carb to this one as I go about this cleaning process, so that will be something I can do easily and have results that will prove things one way or another.

A twenty minute dip will not work, Has to be at least 24 hrs.This will not affect the throttle shaft orings Then use a carb spray, compressed air and a wire to make sure all the little bitty holes are open, then spray and blow out with air again. . I'm hoping when you tore the carbs down, you took out the idle mixture screws and the oring.

[520eek]

A twenty minute dip will not work, Has to be at least 24 hrs.This will not affect the throttle shaft orings Then use a carb spray, compressed air and a wire to make sure all the little bitty holes are open, then spray and blow out with air again. . I'm hoping when you tore the carbs down, you took out the idle mixture screws and the oring.

Yes...I stripped them down as far as one could go without removing throttle shafts. I will soak the "new" carbs" the 24 hour soak and go from there. At least I have all new o-rings on clean jets ready to go!

[Larry D]

Sounds to me like you may have broken the air screw tip off in #3 and while trying to fix the other carbs you may have broken them off as well.

Take a look at your air screws and see if the tip is broken off. If it is, it is probably stuck in the carb body. Good Luck.

http://www.thegsresources.com/_forum/showthread.php?t=212852&highlight=tip+broken

http://www.thegsresources.com/_forum/showthread.php?t=201242&highlight=tip+broken

http://www.thegsresources.com/_forum/showthread.php?t=144701&highlight=tip+broken

[520eek]

The mixture screws looked good when took them out. I will examine them more closely tonight when I get home. I was not all that aggressive when I was trying to adjust them. I will see this evening if that could be a possibility.

[520eek]

Update: Picked up a used set of carbs with unknown history. Stripped them down and dipped each one for 24 hours. Thorough cleaning and compressed air. Reassemble with good cleaned parts, o-rings. Got it running and took it down to the independent shop where the carb sync was done and mixture screws responding. Bike runs much better and even smells better at idle now! Hooray!

Just got to get the gear indicator to stop leaking oil. Looks as if its coming out of the post where the electrical wire hooks up. Is there a good known fix for this? Can I just plug that sucker up and not use the gear indicator display? I mean I usually know what gear I am in.....