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1998 Mercury 135 Gasoline:Oil Ratio

Posted: Sun Jul 09, 2017 11:23 am
by Toddee30
Hello. I've read a lot of great info on here about the oil injection bypass on the older mercury engines. I just bought [1998 Boston Whaler DAUNTLESS] with a 1998 Mercury 135 offshore engine. We bought it from a woman who recently lost her husband. She was able to tell us about the bypass but wasn't sure on the ratio. I couldn't find a specific answer to the ratio for a 135. I assume it's the same 50:1 that everyone is talking about but was curious if someone could confirm this. Thanks for the help--Todd

Re: 1998 Mercury 135 Gasoline:Oil Ratio

Posted: Mon Jul 10, 2017 11:55 am
by jimh
The gasoline-oil ratio is mentioned in the article in the REFERENCE section at

http://continuouswave.com/whaler/refere ... ction.html

The original oil mixing system aimed for 50:1 at full throttle. If the mixer has been disabled and pre-mixing is used instead, the mix ratio would have to be 50:1 if you ever ran at fill throttle.