[wingd]

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I have a 110+k on my 81 wing and just did a compression check and all 4 cylinders are running around 150 ish. Is this tolerable for a 27 year old wing? Mother Honda calls for 171 lbs psi. Is there some kind of spec on this? A plus minus kind of thing?10k milesagoI made a booboo on the timing belt change and just happend to bend a couple of intake valves on the right bank like a few of the other people that use this great site. Anyway I had the head done at my local honda dealer and now that I have arond 110k on the bike,I was thinking of getting the left side freshened upbut I wanted to compare the compression to see if I even needed to do it at all. If it ain't broke ya don't fix it kind of mentality if ya know what I mean. The bike runs great and I just rebuilt the carbs and this is something I should do now if it's needed while thier off.

 

[Hatchetman]

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Your compression is good for the miles on the wing. Many things will effect your compression reading like battery power for a good fast crank during testing, Throttle wide open is a must, Was the engine cold or up near running temp? quality of your engine oil to assist in sealing up the rings to the cylinder wall etc.

there are wings on this forum with lower readings yet they run well. If all your cylinders are within around 10 pounds of each other, your engine is doing very well!

keep the oil clean and ride!

 

[wingd]

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I did the test with the carbs off. Would that make a differance?

 

[Hatchetman]

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Ya got me on that one, I would think that you would get a true reading but I am not sure. I think others will lend an opinion on that one.

 

[wingd]

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Well you would think with the carbs off , it would be like having the throttle wide open and then some. After all you are getting a reading of the cylinder presure when the valves are closed so it probably wouldn't make a differance either way.

 

[chris in va]

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If all four have equal pressure, 150 is fine.

 

[wingd]

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Thanks for all the info!!!

 

[AirCutoff]

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All gauges vary - unless it's way-off you just want to see it close (5psi) between all cylinders. Remember, 10% gauge tolerance could be 15psi one way or the other.

Google "leak down test" and learn about how to do that along with compression testing to qualify engine condition for any piston engine.

My 1100 is +160k miles, heads never off - still shows the same 160psi on the same gauge that it did at 23k miles - 15 years ago.

 

[rayworx]

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You're GOOD! Checking the compression with the carbs off is the same as holding the throttle all the way open. 150 on each cylinder is ok...not perfect but face facts.... it's an older bike with many miles. It's not going to be perfect but it's good enough. I've seen older Wings with 130-140 psi run good.