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blue pipes

Posted: Sat Aug 01, 2015 7:09 am
by bernyboy
I've had my 1984 GL1200 Standard for about a year and a half. I went for my first longer trip ( ~ 1000 km ) a couple weeks back. I am still working on the " won't start when hot" issue, but that is not my concern today. This season it seems to me that my pipes have become more blue. Also I detect a strong gassy smell around the bike, particularly for a time after riding. The bike runs well, too me, though I have no other experience to compare it to. It will pull strongly enough from low revs.The engine sounds smooth, though there is a little backfiring occasionally when decelerating. I get 17 km/liter on the highway with just myself on the bike. I have been using the best gas available, like chevron supreme. Should I be concerned? Does the bluing mean too lean? too rich? I'm not worried about the appearance but what are the serious consequences? What should I do or check?

Re: blue pipes

Posted: Sat Aug 01, 2015 8:37 am
by HawkeyeGL1200
When chrome gets hot, it changes color. It isn't abnormal for some bluing to occur... if the pipes get purple or brown, it's probably a fuel/air mixture problem. If you have access to a set of gauges, it wouldn't hurt to make sure the carbs are balanced.. I think things are probably okay

Re: blue pipes

Posted: Sat Aug 01, 2015 8:39 am
by wingman12
good morning, the blue pipes are caused by running to lean. this could also have something to do with the popping when decelerating , change from premium back to 87 oct, you will find the bike runs better on 87. use brand name station, run seafoam in your fuel for 2 or three tanks of fuel to improve your carb performance. :D :D

Re: blue pipes

Posted: Sat Aug 01, 2015 5:04 pm
by RoadRogue
These bikes were designed to runn on regular gasoline, 87 octane. Running them on supreme wont hurt it any but really is a waste of money. Higher Octane is needed in High compression engines to prevent pinging or predetonation. These engines get no benefit from high octane fuel. Backfiring on deceleration is usually caused by a leak in the intake ,allowing more air into the cylinders under high vaccuum conditions like a closed throttle when engine braking. Air in after the carbs gives the unburnt fuel in the exhaust the oxygen it needs to ignite and you get popping in the pipes.
The gas smell after you stop usually is because the bike is hot and the vapors in the tank are slowly vented out the cap. This is normal.
I live in Castlegar, only 3 hrs west from you. Next time you are out this way look me up and we can compare notes on your bike PM me for my number. 8-)

Re: blue pipes

Posted: Sun Oct 11, 2015 6:23 pm
by knowhoweman74
I have an 86 GL1200A that is backfiring exactly as described. Is there a vacuum line I need to check and if so where do I find it or is there something else I need to do?

Re: blue pipes

Posted: Sat Oct 17, 2015 8:51 pm
by f1xrupr
Blueing is ok-try starting hot engine at 1/3 throttle.