Carb still pops after rebuild - Printable Version

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Carb still pops after rebuild - Guest - 08-27-2008

Hi Everyone

I have a 1985 GL1200 Interstate. I just finish rebuilding the carbs with Randakk's carb kit, I also syncronized the carbs and I must say it does run better but I do not know for how long. I still get the carb to pop at about 2000 to 3000 RPM's but not all the time.
I sure could use some suggestion's about now, I really don't have much left to pull out.
So far since my recent purchase of this machine, I have rebuilt the front forks (Seals and springs), I have replaced the timing belts. then of course the carb rebuild. My investment is getting out of hand in repairs, and the time it has consumed has been also been as great.
My mechanic told me that there was a small exhaust leak but I haven't found it.
I don't know if a leak in the exhaust could cause this problem I am having with the carbs, or maybe something else.
Any suggestions?

Re: Carb still pops after rebuild - Oldman - 08-28-2008

I found a small exhaust leak once by using flour. The leak blew it off the pipes at the hole, but an exhaust leak usually causes backfire out the end of the bike in a loud "bang". A cough is from the carbs. Have you checked all the electrical connections involved with the ignition? A little bit of corrosion can cause resistance with can lead to a case of the carb coughs also. I'd stop throwin g money at it and spend some one on one time with the bike and a manual.

Re: Carb still pops after rebuild - MikeM - 08-28-2008

A piece of hose ( Garden hose etc.) Is great for finding exhaust leaks. Place one end of the hose to your ear and move the other end along the exhaust system. You will know right where the leak is. :wink: My 84 was popping at a idle intermittently and it turned out to be the plug wire ends were touching each other. I separated the wires a bit and the popping stopped. I'm guessing the spark would jump to the wrong plug and fire when that cylinders intake valve was open? Never got a chance to investigate it farther. When I started the 85 this AM I could hear a ticking noise similar to a valve tick on the left side. I looked down and saw the same thing. The plug wire caps were touching and arcing between the wires and caps.

Re: Carb still pops after rebuild - cjh - 06-21-2011

been thru this . I changed pilot jets to bigger, didn't work, changed them back to stock. Ended up putting a .045 inch shim under needles . bike never ran so good.

Shim? - MRGONE - 10-23-2011

The shim mentioned under the needles, is this like a washer put under the diaphragm to lift the needles ?
Regards Len