Exhaust temperature ?

[shesseltine86]

I just finished putting my bike back together and it runs great. I was checking the temp of the exhaust pipes and the outside two run cooler than the inside two, is this normal ?

[Mr Jensee]

I believe on any 4 cylinder they should all be equally warm. I had an air cooled GS that did what yours. The cold cylinders weren't firing. I ended up replacing the coils and wires. Hopefully you wont have to do the same but check the plug caps. They unscrew off the wires. You can take them off, cut a 1/4" off the ends and screw the caps back on to see if this improves spark. First pull the plugs and make sure the gaps are correct and turn the engine over with all the plug caps removed. Make sure you are getting spark and work backwards from there. Remember spark, air, fuel. check anything that affects that.

[Tonyvdb]

I do believe that only 2 of the 4 exhaust pipes at the rear of the bike are actually real the other two are just show. There may be a small crossover pipe to the other two but they do not all go back the motor as one might think.

[Tim in NC]

The parts diagram for the Exhaust System shows that cylinders 1 & 2 pipes join into a single pipe on the left, and same on the right for cylinders 3 & 4. Then the single pipe go into the muffler, which has two tail pipes coming out of the muffler on each side. Also a crossover pipe under the engine.
As long as your pipes are hot at the engine exhaust port (don't touch them... don't ask), you should be good.

[ghostler]

Wasn't quite sure what shesseltine86 meant, if pipe portion that exited the cylinder head or tail. If both inner exhaust are cooler, suspect either not firing or getting significantly less fuel air mixture from corresponding carburetors.

Don't think he was meaning the muffler tips. On my 2001, the two outer are the real exhaust, two inner are chromed dummies. Each side is 2-into-1 exhaust, as Tonyvdb stated.

Some time back without thinking, I found out the hard way. I was wondering why no exhaust output on two inner muffler tips.
"Hey, she's only running on 2 cylinders during idle."
Then I noticed the 2 into ones.

[Mr Jensee]

You can use a digital thermometer on the exhaust pipes coming out of the engine head to see if any are cooler than the other. It makes no difference that they all converge further down the line into two mufflers. As long as there are no constrictions you have no issues. What I posted above is accurate if your exhaust manifolds are considered cold. A four cylinder engine with run on 2 cylinders often times without you hearing the difference. Performance at idle and at speed will be sluggish if any cylinder is not firing and burning fuel as efficiently as the others. Check the plugs first. Cold cylinders will have wet dark looking plug ends. Normal plugs will appear light brown in color.

[shesseltine86]

Thanks guys , I was looking at it with a digital thermometer right as they leave the heads. I know the # 1 is getting spark, so it would be a fuel problem. On another note, I can't seem to get the rear brake pedal bled down like I would like to see. It will lock the rear tire up, but it takes a lot of travel on the pedal.

[Mr Jensee]

Before bleeding any of the brakes, if you haven't already ordered a set of speed bleeders I recommend doing so. It is a one way brake valve that allows you to bleed disk brakes without any air from backing up into your system. These will replace the existing bleeders. This should simplify changing out brake fluid without the hassles. go to http://www.speedbleeder.com" onclick="window.open(this.href);return false; for details. You will need one for each brake, plus one for the hydraulic clutch.

[Lucasind]

" On another note, I can't seem to get the rear brake pedal bled down like I would like to see. It will lock the rear tire up, but it takes a lot of travel on the pedal."

To fix this quickly...pull that rear caliper back off,remove the pads,get a c-clamp,and squeeze the piston all the way back into the caliper and leave it there,repeat the bleed process, your trapped air will come out in less than three bleeds.Your brakes will return to normal ,with a nice high pedal......................Tony

[shesseltine86]

Thanks! I will do that today!

[shesseltine86]

Lucasind, that worked great, thanks!

[Lucasind]

Happy to help ! also PM sent to you.

[Lucasind]

Hey all right Scott ! I just noticed that your user name has changed from red to GREEN
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