Just wondering

[Franky112665]

Took a compression test today on my Yamaha pro v 150g. The readings were 115,105,100,110,115,110. I know they are suppose to be within 10. I have one that is out of range. How long can I run with the compression below range. I don't have a repair manual so can anyone tell me what they should be at a normal reading.
Thanks for the help in advance.

 

[JB]

Re: Just wondering

Range is on the edge, Franky. Not serious. Many books say 10-15% and you are within that.

Do a decarbon treatment and check again. Let us know.

 

[Franky112665]

Re: Just wondering

How is the best way to decarb? Is it with ring free. Or do I use something else. I have the carbs off and apart soaking in carb cleaner. Waiting on gasket set to get here ( any day now). I found a PDF file of a owners manual and says spark plug gaps between .35-.39. Ive got them at .35. Is that okay? Thanks again. New to boating.

 

[JB]

Re: Just wondering

You are fine on the gap, Franky. Check the Engine FAQs forum for info on decarb. Basically, select any product and follow the instructions on the can or bottle. Seafoam is very popular, but there are others just as good.

Good luck.

 

[robert graham]

Re: Just wondering

The Ringfree at the "Decarb" dosage on the bottle, run about 12 gallons of gas through the motor at that dosage. Not much difference in running of the motor between .035" and .039" plug gaps. Also, if you run those compression tests several times for each cylinder, you could get slightly different readings each time. Sounds like you've got a pretty healthy motor to me! Maybe order a Yamaha Manual for your specific motor...lots to read and learn about! Install a fuel/water separator type canister filter(Walmart/Attwood $27), great preventive maintenance for fuel related problems. Good Luck!