Compression numbers for a 2007 bf225

Purchasing a Everglades with Honda bf 225 on it, I had a compression test done on the motor and the numbers are as follows; #1 180, #2 180 #3 210 #4 200 #5 190 #6 195. The motor has 498 hours on it. Are these compressions numbers in an acceptable range?

Within 10% is generally considered acceptable. Youre just on 10%. Was the engine warmed up to running temp before performing the compression test?

Not sure if the engine was warmed up before performing the compression test. The compression test was completed by a local mechanic. I have concerns about the variance between the cylinders compression. Am I overly concerned? Should I consider having a second mechanic preform a second test for accuracy. Thank you for any feed back as I am a new member and hopefully will be a Honda owner soon.

If it was performed cold you may find the numbers even out a little once warm. Ideally all the numbers would be the same but within 10% is generally considered within tolerance. The lower of your numbers seem a bit low to me, ideally they would all be over 200. Things you could try to bring up the compression (and hopefully even it out):

compression test the motor warm.
if motor hasn't been used for a long time then run it on boat for a few hours first.
Run a decarboniser through the engine like Yamaha ringfree (at same time as above)
get the valves adjusted.

if the motor is running fine and none of the above have been done to try and get better compression readings then Id say there is still more to do before giving it a final diagnosis. It could all be rectified with a $25 fuel additive.

if after all that you still have low comps in some cylinders then a leakdown test will help your determine where the problem is.

Yep - numbers are slightly low - all should be over 200 and no more than 10% difference between the highest number and lowest number. I agree with Skronkman on how to improve them. Valve adjustment would be at the top of my list. It should be done every 400 hours anyway. If that doesn't get you within specs, then decarbonize the engine using a concentrated decarbonizer like the Yamalube Ring Free.

Ditto....only I would decarbonize first. If you adjust valves first, then decarbonize (and it has carbon buildup), that may change the clearances on the valves. Then you should check/adjust them again.


Mike