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Re: Popping anyone?

Posted: Fri Apr 08, 2011 12:10 pm
by spencer
I doubt your gaskets need to be replaced. If they are leaking, something is not clean, or they are not properly installed. It sounds like your needle valves may not be working as they should. That could account for the "leak" if one or more valves are allowing a carburetor to fill till it overflows. The complete valve, from Honda, is expensive - about $40 each. If the brass valve seat, the washer, and the filter are in good condition, you probably only need the needle valve. I don't believe Honda will sell only the needle, but you can get genuine Keihin needle valves from a couple of places, and if everything else is OK, they will fix your problem. I bought six of them from PJ Motorsports, and they fixed all of my needle valve problems. If you order from this page on the PJ Motorsports web site, you can get them for $12.95 each: http://www.pjmotorsports.com/vintage-mo ... lve%20assy They are item number 018-880. I believe Sudco also sells the same needle valve for less than $10, but I can't be sure, since I have not ordered from them. The needle valves from PJ Motorsports are genuine Keihin parts, as you can tell from this picture.

4564

Re: Popping anyone?

Posted: Fri Apr 08, 2011 6:29 pm
by Jeff Bennetts
Hey Spencer, there is a boat load of good carb tuning information on that website you posted above.

Re: Popping anyone?

Posted: Fri Apr 08, 2011 10:37 pm
by daves79x
The recommendation for your 'bowl' leak is to find out where the leak really is. Unless you pinched one, bowl gaskets that new are good for a long time. Jeff's suggestion is good also, as the float valves you described would not seal properly and overflow - a dangerous situation as it could quickly fill a combustion chamber. However, you should also see evidence of overflow out the drain tubes. Make sure they are not plugged.

Dave

Re: Popping anyone?

Posted: Fri Apr 08, 2011 11:32 pm
by spencer
Dave is right. The real danger is that a leaking bowl valve could allow a cylinder to fill with gas, and we all know what that can do. That was the reason I wanted to make sure I bought genuine Keihin needle valves. I just forgot to say so.

There is one other possible cause for the leaking. If everything else is good, you could have a cracked overflow tube in the bowl, allowing gas to leak out. But, from your description of the spring loaded plungers on your needle valves, that is more likely to be your problem.

Re: Popping anyone?

Posted: Sun Apr 10, 2011 12:08 pm
by SPLINTER
Am I paying the price for something I did in my youth? Have the carburator gods foresaken me? Do I need to start writing my will? or... is it time to buy a...Oh no!!! a Harley!!!! I'm running out of options and needless to say patience. I replaced the float needles and adjusted the floats as indicated. Thought for a moment that this would solve the problem...and presto! nothing! Same irregular idling. Popping every so often. I'm about to go through the electrical system in hopes that I'll find the culprit. I would hate to let this beast conquer my manhood. Thought of taking Mr Mike Nixons offer to send then to him for an evaluation...just hate to bug this man that is constantly getting requests for information. I'm sure he is overwelmed with them. Just hate to impose with my problems too. Any other helpful information that anybody can share, before my girlfriend decides to jump ship, would be greatly appreciated. Oh wait...looks like she's started packing her bags. May be too late. I'm still holding on to the possibility that the next thing I do will solve the problem. I will remain on standby for all suggestions, no matter how far fetched I may think they are. In the mean time I will double my order of Prozac to keep things bearable. :cry:

Re: Popping anyone?

Posted: Sun Apr 10, 2011 12:20 pm
by EMS
Could it be that the popping is caused by an air leak on the intake side? :?: :?:

Re: Popping anyone?

Posted: Sun Apr 10, 2011 12:42 pm
by SPLINTER
Very unlikely. Boots are new and clamps are nice and tight.

Re: Popping anyone?

Posted: Sun Apr 10, 2011 12:53 pm
by EMS
Are your cam chain tensioners working properly. A slight slack causing relative cam timing going off could have more of an effect at engine idle.

Re: Popping anyone?

Posted: Sun Apr 10, 2011 3:34 pm
by SPLINTER
To the best of my knowledge, yes. I try to stay on top of regular adjustment periods. Seems like the popping may be getting a bit worse. Brought the idle mixture screws back to 2 1/4 turns. Re-cleaned (or went through the motions) the idle jet that sits aside the 1st carb. Sprayed cleaner and compressed air. Drained all cleaner, reassembled and no change.

Re: Popping anyone?

Posted: Sun Apr 10, 2011 6:20 pm
by spencer
Well, you seem to have tried a lot of things, with no change. Are you sure the occaisional misfire is abnormal? One man's misfire and popping might be another man's normal idle. I know this might be hard to do, but is it possible that you could make a sound recording so that everyone can hear what you are talking about? Maybe a video recording, but all that is really needed would be audio. At least, that way, everyone would be able to hear what you hear.

Re: Popping anyone?

Posted: Sun Apr 10, 2011 8:11 pm
by NobleHops
Could cracked coils cause this? Or old plug wires?

Re: Popping anyone?

Posted: Sun Apr 10, 2011 8:22 pm
by SPLINTER
Nills, the wires are maybe 4 years old. Coils appear to be OK, visually. I'm speechless. Its even worse now, after I adjusted the floats and re-sprayed and compressed air cleaned the jet on carb#1, the one on the side. Going down the road at 5000 rpm's you can't really notice it but I know its still there. Its a real disscouraging process.

Re: Popping anyone?

Posted: Mon Apr 11, 2011 12:11 am
by spencer
SPLINTER wrote:Its even worse now, after I adjusted the floats and re-sprayed and compressed air cleaned the jet on carb#1, the one on the side.
There is no jet on the side of carb #1, but someone refresh my memory. What is the symptom of a bad air cut valve?

Re: Popping anyone?

Posted: Mon Apr 11, 2011 1:50 am
by Kool_Biker
SPLINTER wrote:Am I paying the price for something I did in my youth? ... I'm about to go through the electrical system in hopes that I'll find the culprit. :cry:
I have read your posts carefully and not sure your problem 'sounds' electrical...
However if you decide to delve in this direction, you might get some ideas from an earlier problem I had as below:
viewtopic.php?f=20&t=6970
It certainly solved my problem. Aris

Re: Popping anyone?

Posted: Tue Apr 12, 2011 11:05 am
by SPLINTER
I will check the coils this weekend and try and find a problem if any. Will post the results as soon as I can.. Thanks everybody for the input. I'm trying my best to get to the bottom of this.