1986 150hp Possible Low Compression??

[Rv8ter]

Hello All,<br />My apology in advance "JB" if I am in the wrong forum, however I am looking to upgrade from a 1995 115hp 2 stroke Yamaha to a 1986 150hp 2 stroke Yamaha (Yes, it appears that I am "upgrading" in the wrong direction), and have been looking at a supposedly recent rebuild, alleged 30-40hrs, however the compression is 90lbs on five of the cylinders and 89 on the last one. This seems low to me.<br /> What say ya'll? <br />Thanks <br />lonlynn@bellsouth.net

 

[rodbolt]

Re: 1986 150hp Possible Low Compression??

numbers look ok to me. could be your gauge or method, yamaha says 10 PSI bank to bank. its normal to see a spread from top to bottom. but they dont like to give specific numbers cause there is no gauge calibration procedures.<br /> you will need all the harness adapters to reuse your trim and oil pump and alarm wiring. the connectors changed from round to square about 94 or so on most and all by 95.

 

[Rv8ter]

Re: 1986 150hp Possible Low Compression??

Thanks Rodbolt for your quick reply <br />These readings came from the seller, as I have only seen pictures of the engine.<br />Sounds like I would have a lot of updates to accomplish the "Upgrade" as my 115 doesn't have oil injection and the 150 does. This may be over my head.<br />Thanks again