First service and a question

[workerbee606]

I just had my first service done on my 2012 yamaha f115 and got a good to go from the mechanics. My question is this, the compression test was 215 psi on #1 thru #3 and 210 on #4 cylinder. This motor has 12 hours on it and I followed the break in schedule to the letter. Is it normal to have one cylinder have lower compression than the others?

 

[tpenfield]

Re: First service and a question

They won't be absolutely the same and the method and tools of measuring is not 100% accurate. . . so the numbers are good if within +/- 5%. Yours are about +/- 1% . . .