Seems like cylinder 1 and 2 are the only two firing...

[koolaid_kid]

Did you check compression with the throttle open? Your numbers are typical with the throttle closed.
And,
The most likely place to lose compression is through incorrect valve clearances. The clearances normally get tighter with wear, especially on lower mileage engines. There can be no compression if the valves are not closed. If you run it this way, you will burn valves.
Again, check the clearances. .03mm is the very minimum, .08 or even .10mm is better.

Good point. I suggested that he get the compression test procedure from BassCliff's site, but that may not have happened. IDK.

[tkent02]

On these bikes, if it still has low compression after the valve clearances are dialed in, you will need to pull the head and the cylinder block.

Maybe, maybe not. Sometimes the compression will come back up after everything is adjusted correctly and after the engine runs several thousand hard miles...
Of course it depends on what exactly is causing the problem.

[koolaid_kid]

Maybe, maybe not. Sometimes the compression will come back up after everything is adjusted correctly and after the engine runs several thousand hard miles...
Of course it depends on what exactly is causing the problem.

True dat. Of course, that is the "cross my fingers and hope it fixes itself" approach. I could see that if the valve seats are carboned up. If the rings are stuck, isn't there a method sometimes employed, like pouring a bit of Marvel Mystery Oil down the plug hole to try to free them up?
I am also confused by the "and it leaked down quickly" part. My tester has a schraeder valve in it to hold the pressure until I press the button.

[rustybronco]

Here's a DIY leakdown tester.

http://www.motorcycleproject.com/motorcycle/text/leakdown.html

I'll post my 'variant' of it when I get home tonight.

[koolaid_kid]

Here's a DIY leakdown tester.

http://www.motorcycleproject.com/motorcycle/text/leakdown.html

I'll post my 'variant' of it when I get home tonight.

I have this one from Harbor Freight: http://www.harborfreight.com/cylinde...ter-94190.html
I searched all around the web and found the exact same model carried under various brand names from $50-80.
With their 20% discount it makes it $28 plus tax. And it comes with a case.
Just a thought.

[BassCliff]

Hi,

Please visit my little website. You will find "how to" guides for most regular maintenance tasks and a lot more.

I forget, is the '82 GS550 a 16 valve engine? If so, use the 16 valve procedure to check the valve clearance and not the 8 valve procedure.

Thank you for your indulgence,

BassCliff

[tkent02]

I have this one from Harbor Freight: http://www.harborfreight.com/cylinde...ter-94190.html
I searched all around the web and found the exact same model carried under various brand names from $50-80.
With their 20% discount it makes it $28 plus tax. And it comes with a case.
Just a thought.

Where do I get the 20% discount?

[rustybronco]

I already had the compression tester, so I thought I'd combine it with a few brass fittings and make it a dual purpose tool.

I have this one from Harbor Freight: http://www.harborfreight.com/cylinde...ter-94190.html

[Defore]

Thanks alot!

[koolaid_kid]

Where do I get the 20% discount?

Car mags, bike mags, diy mags. I have even gone to the public library and "borrowed" them from their mags. They get tossed at the end of the month anyway.
Also, if you get Sunday's paper they are buried in one of the "ad sections" every week.
Not sure if they have them in South Park, but you get my drift.

[rustybronco]

http://widgets.harborfreight.com/wswidgets/common/displayCoupon.do?hdr=mag&week=5211&campaign=b&page=5211b_appends2.html&cust=99999999999&keycode=1007

[Defore]

Awesome so I just checked the clearance but I only had a .07 feeler and they were all a tad bit bigger on clearance id say a .09 or .10. Now what?

[rustybronco]

Open the throttle, add a teaspoon of engine oil to each cylinder and retest and pay careful attention to your compression gauge not holding pressure.

[tkent02]

Awesome so I just checked the clearance but I only had a .07 feeler and they were all a tad bit bigger on clearance id say a .09 or .10. Now what?

These are metric feeler gauges, yes?
And do a dry test before you add oil for the wet test, it's hard to do a dry test after it's wet.

[rustybronco]

Here's a DIY leakdown tester.

http://www.motorcycleproject.com/motorcycle/text/leakdown.html

I'll post my 'variant' of it when I get home tonight.

Variant posed in this thread -> http://www.thegsresources.com/_forum...62#post1559962