Bing Carb Tune up

[tmc3c]

After having my carb cleaned and all of the jets cleaned and the carb put back together by a local shop what kind of adjustments do I need to make to it and also while the bike is running ? When I first rode the bike it was smoking pretty good and I rode it for a brief time and it quit running and then I took the carb off and found the float needle laying in the bottom of the bowl,so I reinstalled it and adjusted the float and reinstalled the carb and cranked the bike and it would only stay running with me holding the throttle open,so I tried adjusting by ear and it cleared up and sounded good then it started reving to the moon so I hit the kill switch and took it to a local shop for some help and he said the carb is shot. This being said after he was the one who cleaned it and without looking in again. IDEAS

Thomas Carmichael

[Doug Wilford]

Tom;
It sounds like your bike needs new seals both on the primary side and the ignition side.   ??    Just trying to help.

[tmc3c]

Hey Doug,  Thank You for your input but the motor is Brand New straight from Kip Kern !! And I just installed the "NEW " PVL system.The carb slide is wore pretty good and I have been told that this can cause me problems also,and there is the carb barrel being wore and some build up at the bottom of the barrel where the slide bottoms out in the carb. Sure was nice when I could just push it over to my Dad and ask him to fix it. I feel I am so close !!

Thomas Carmichael

[Mike OReilly]

What you describe certainly sounds like an air leak. It could be at the seals or at the intake spigot. I don't know how much slide wear would be necessary to get it to rev to the moon, but slide wear will only usually make it difficult or impossible to get a good idle. The bike should be rideable otherwise.
Do you have access to a known good carb? (i.e. borrow one from a fellow POG'r). This would allow you to eliminate that as a question mark and isolate the problem.
Mike

[Mike OReilly]

...so then I go to "Wanted/For Sale" and see that that is exactly what you appear to have done.
Good luck,
Mike

[Jdbglover]

Hello,


You may also want to retorque the head bolts.  The following link is to a prior post concerning a similar problem and also included is a link on how to build a cheap air leak tester.

http://pentonusa.org/forum/topic.asp?TOPIC_ID=2323&SearchTerms=head,test

John

[tomale]

Thomas did you say that the bike has a reed valve? I think that it would be a good idea to check to see what kind of shape they are in. on the older bikes it is not as critical but i understand that it is critical on the newer bikes where the intake dumps directly into the crank case. none the less this could mess things up. Several people have had trouble with the bings. I never could get mine to meter correctly. I understand that the parts of expensive as well. I put a mikuni on mine and have loved it. It is easy to jet and easy to get almost anywhere. the total cost was pretty cheap as well. with everyting including the carb I have less than 150 bucks invested.

just something to think about. You can't win if you don't finish and if you fix a problem with out really knowing why how do you know that it won't do it again?

Thom Green,I own and ride a 76 250 MC5 MX which I bought new.

[wildman]

A little note about Bing carbs that I've never seen mentioned concerns the guide tab crimped into the carb body to guide the slide up and down. The guide will loosen in the carb body and leak air in as well as dirt. A dab of silicone sealer is all thats needed to seal it. This may or may not have bearing on your problem but every Bing carb should have this done, I used Penton orange silicone seal:). Keep checking, you'le find the solution. Bings are good carbs if not worn badly.Happy Trails, Dan Pagel

1975 250 Cross Country, 1974 175 Jackpiner, 1975 125

[tmc3c]

Thom, I have brand new Boyesen dual stage reeds. Everything is new except the carb. Kip Kern went through the motor from top to bottom, that is why I say it is "BRAND NEW" so I don't think it is in the motor. A fellow pogger is sending me 2 bings and with mine in hand we are going to have a telephone session and try and make one run right.

Thomas Carmichael

[tomale]

I was not sure and the thought crossed my mind so I thought that i would share it. hard to know sometimes. I did not mean to be critical. if i was please forgive me. Sounds like a good plan hope it works out for you. it is hard when you know you are so close and it still does not run like you know it should. take care and let me know what you find.

Thom Green,I own and ride a 76 250 MC5 MX which I bought new.

[firstturn]

Thom,
  I have sent Thomas 3 carbs in various stages of degeneration.  I'm hoping that we can get him running with this Heintz 57 selection.  If not Our POG Statesman Don Roth has one he can buy.  I think the Mukuni will be the ticket if we can't poor boy it.  Your input is valuable.  I just hate to see someone who has spent this much money and the thing still is not right.

Ron Carbaugh

[tomale]

Thanks Ron, as always you are a gentlemen. and a true and valued friend.

Thom Green,I own and ride a 76 250 MC5 MX which I bought new.

[tmc3c]

Hey Thom, I really value your input and I sure don't think you are being critical at all ! When you feel as close as I do about getting this baby running RIGHT you are open to any suggestions.Thank you again!! Say are you racing in Mid-Ohio?

Thomas Carmichael