[outlawearl]

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Ok, I am going to try & do a comression test on my 1982 GL1100. I have never done one before & hope someone can explain how to do it accurately. The tester has instructions but sounds like for a car. Would it be the same on a bike.

Thanks & remember the KISS

Keep it simple STUPID!!!

 

[Tonys96]

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Yes similiar to a car, but you can use the kill switch to keep the engine from firing, rather than disabling the ignition.

 

[twisty]

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outlawearl wrote:

Ok, I am going to try & do a comression test on my 1982 GL1100. I have never done one before & hope someone can explain how to do it accurately. The tester has instructions but sounds like for a car. Would it be the same on a bike.

Thanks & remember the KISS

Keep it simple STUPID!!!

outlawearl, it's about the same as for a car.. Warm the engine,, let it cool for a few minutes,, remove all the spark plugs,, open the throttle & hold it fully open,, short out all 4 plug wires (or turn the kill switch off),, then install the compression gauge in a cylinder & crank the engine (do that for all 4 cylinders).. You want to see what the MAX compression is for each cylinder & how many puffs it takes to reach max compression..

You want to see the max compression between cylinders tobe 10 psi or less & about the same number of puffs to get it there.

If your compression is low or it takes many puffs to get it there check for a plugged air cleaner.

Twisty

 

[outlawearl]

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Ok I think I did it correctly. Here are my numbers. No.1=132, No.2=130, No.3=145, No.4=139. The reason I did the test was because my number 3 plug was fouling,( see the thread #3 plug fouling for more info) Am I safe with these numbers on my engine? Should I look toward the Carbs as the problem?

 

[twisty]

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outlawearl wrote:

Ok I think I did it correctly. Here are my numbers. No.1=132, No.2=130, No.3=145, No.4=139. The reason I did the test was because my number 3 plug was fouling,( see the thread #3 plug fouling for more info) Am I safe with these numbers on my engine? Should I look toward the Carbs as the problem?

outlawearl, yes, those numbers look pretty consistent. That higher #3 cylinder is probably either due to carbon build up in that cylinder from the mis-fire or the rings in that cylinder have more oil on them from not firing correctly.

As far as looking at the carb(s) possibly, either that or an ignition malfunction.

Twisty

 

[outlawearl]

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Thanks Twisty, What would I look for in an ignition malfunction?