Newbie Question about a cold pipe.

[goingtothedesert]

-1980 GS550E
-30,000 miles
-Has been running pretty good except it will not idle without me giving it just a little gas or turning the idle up high for me since I bought it a few months ago.
- Recently done: Oil change, Spark plugs, Brake light lever switch (front), verified that tank is clean of rust. put high test gas in and some octane booster.
-Searched the forum for same questions

Issue- Bike is running okay but I know there is more power in her. I read a lot about cold pipes in these forums and after checking my bike I found out I do in fact have 1 cold pipe. That may be why I have such a rough time keeping her going at anything below 2K RPMs without stalling (She runs fine though if I keep the idle set high) anyway, the left most pipe is cold. My question is does each pipe from the left 1 , 2 , 3, 4, correspond with the plugs from the left 1, 2, 3, 4 ? With that info I can troubleshoot the correct cylinder and carb.

Thank you very much for your help!!!

[J_C]

Yes. Remember that an engine needs three things to operate. Fuel (fuel/air mixture) compression, and spark.

Compression is easy to check off if you have a compression gauge. Spark is relatively easy too by holding it against the fin and checking for a phat blue arc. If these two things check out, start looking critically at the carb or the chance of any vacuum leaks

[goingtothedesert]

So each pipe , carb and plug run together from the back to the front correct?

[J_C]

Yes, there's no crossover or anything

[GS550joe]

where is the vacuum tube

Is your vacuum tube coming from the proper place?? mine was connected to the #1 vacuum nipple on the intake boot when I got it.. moved to the #2-3 tube where ther was vacuum from the carbs.. then blocked it off on 1 and later removed the tube bcuz of gas in the tube and blocked the vacuum..

check the vacuum takeoff and the petcock vacuum port as discussed in several postings

Joe

[goingtothedesert]

I just noticied that there is a little gas build up by that CARB dripping lightly from the bottom. Do you think something can be stuck inside the CARB?

[J_C]

Could just be a bad seal on the drain plug or a bad gasket or something, or maybe the float is too high... I'm not really sure what might be causing the problem but you may want to pull the carbs for a cleaning regardless.

Someone much more knowledgable than I will be able to guide you better.

[Basket Case]

I'd recommend NOT going with the high-octane fuel. My old GPz ran like crap on 91 octane... the old bikes seem happier with 85 or 87 (depending on altitude)

[jrciamacco]

My 450 had a cylinder cold and it had a horrible power loss. It is only a 2 cylinder of course but none the less...Just kept fouling plugs because of a lean mixture problem. Check the spark on that cylinder and make sure your carbs are synched and that your mixtures are all set correctly...around two turns out usually

[goingtothedesert]

This is how I fixed it.

This is how I fixed it.....After taking the carbs out and dipping them (following the directions you will find on this site) everything works fine.



Note: buy the o-ring kit you can find a link for in these forums somewhere. I had to rebuild my carbs 3 times because of leaking gas UNTIL I put in new o-rings.

Everything runs fine now.