Yamaha 130 two stroke compression

[Cajun Salt]

I have an extra pair of 1998 Yamaha 130 2strokes. They have about 1000 hrs on them and have been well used and well cared for but I have upgraded. I have a guy who may be interested in buying them but he wants compression numbers. I am no mechanic but I want to be sure to give the guy accurate reports. I have borrowed a compression gauge and am charging the boat batteries. Is the correct process to remove all spark plugs and install the compression gauge in one of plug holes then turn the engine over with the starter until the gauge tops out showing me the maximum compression of that cylinder? Then repeat the process for each cylinder? What compression numbers should I expect from these motors if there are no issues?

Thank you


Cajun Salt

 

[Scout 175]

Re: Yamaha 130 two stroke compression

I think that subject is covered in the FAQ section.

Good Luck
Scout 175

 

[crb478]

Re: Yamaha 130 two stroke compression

That is the correct process.

 

[yamatech43]

Re: Yamaha 130 two stroke compression

The numbers aren't so important as not wanting a variation between the highest and lowest compressions of more than 15 percent....if you have not run the engine for many months you should run it first as you may have some sticky rings in there....may affect test if so.

 

[99yam40]

Re: Yamaha 130 two stroke compression

Don't forget to pull the kill switch to keep from having spark jumping everywhere while turning over with out the plugs and wires attached