1980gs450l no left cyl fire when cold

[edhuhn]

I am trying t get my sons 450l running after setting for about 2 years. When I first start it, only the right cyl will fire. lots of gas smell out of the left pipe, but it satys cold. After it warms up (about 3 min) then the left cyl will spit and sputter, then it will fire and all is ok. I pulled the plugs, and have good spark all the time (cold or hot). I didn't run a compression test yet. Does this sound like a carb issue ?

Thanks
Ed

[fabinator]

That happened to me. I synchronized the carbs, and adjusted the pilot screws, and all was groovy.

I don't have a set of carb sticks to sync them with, but I don't have an airbox either, so removing them is easy. I found that getting things close with the carbs off the engine, then re-installing the carbs got things pretty close. I didn't tighten down the linkage screw, and fine-tuned the carbs while on the bike. I did it by pulling one plug wire off at a time, and adjusting the carbs so the engine will idle at the same speed for each cylinder. However, for this to work, you need dead equal compression. I had 172psi on one cylinder, 173 on the other, I consider that close enough to sync carbs this way.

Also keep in mind, my methods are either what I see, or what I figure out with some thinking. I've been wrong before, and I may be wrong now. Don't let the engine run on only one cylinder longer than absolutely necessary, you may wash down the cylinder and kill the rings.

[mortation]

1) Check for vacuum leaks. May seal up when the engine gets hot.

2) Adjust your mixture screws using a colortune or highest RPM method.

3) Balance the carbs, I would say use the right EQ. Its like $60 from motion pro or if you live in CT you can come by my place and use mine.

You may have a bad boot o-ring.

[kb9lae]

Don't forget to change that air filter as well. It makes a HUGE change!

[fabinator]

Adjust your mixture screws using a colortune

What is this? I'm curious.

[edhuhn]

I ran the bike a little more today. It runs strong when warm, but when cold, it spits raw gas out the left exhaust. I think I'll pull the carbs apart this week and check them / clean them.

[doggscube]

I had this exact issue recently after a leaking petcock issue. I followed the advice to put a little oil into the problem combustion chamber to help free up the rings. Since the petcock replacement it had repeated problems with this, but this morning it started up on two cylinders just fine.

Jeff

[edhuhn]

It looks like the more I run it, the better it gets. I will drop the carbs and clean them, and do a set up on them. Now if I only had the time.....

Ed

[edhuhn]

I got the carbs torn down today. I found a bad float. It has gas inside it. If I shake it, I can hear the gas sloshing around in it. I moved it to the right side, and the problem moved with it.
Now I have to start hunting down a float for it. I think I will also look for a set of 125 main jets and 22.5 pilot jets. It has pods on it, and I might as well do it all while I'm in it.

Thanks

Ed

[R1209]

I got the carbs torn down today. I found a bad float. It has gas inside it. If I shake it, I can hear the gas sloshing around in it. I moved it to the right side, and the problem moved with it.
Now I have to start hunting down a float for it. I think I will also look for a set of 125 main jets and 22.5 pilot jets. It has pods on it, and I might as well do it all while I'm in it.

Thanks

Ed

Did u check the needle and seat

[R1209]

Also u might want to change your oil. because of the oil dumping into the cylinder. good luck

[edhuhn]

yes It looks like the float is bad