Regular gas in my 235 Johnson

[PHISH]

I have taken my boat to two different mechanics in the last year and both told me that I can run regular pump gas in my early 80's OMC, even with the higher compression heads. Any experienced OMC friends or people on the net have warned me to run at least 91 Octane.
Its not the money, its just that I am on a 23+ mile lake and there is no gas stations that carry 91 or over so I have to bring my own fuel up every weekend and it would be easier to fly the whole weekend and not worry about running out.
Also - I have been told to mix 50:1 with oil, but others tell me 40:1. Is 40:1 too rich?
Cheers
Matt

I know this should be in tech talk but I wanted some quick answers.

[vector mike]

Check your compression and see what it is. If it is a little high just back off the timing a bit. You will scrafice a little performance but be able to run the cheeper gas.

[NicePackage]

Sorry for the off topic but I don't recall seeing you post in the thread about the bogbash on scugog tomorrow. They don't know me and I'm invited, so you should come.

[PHISH]

Check your compression and see what it is. If it is a little high just back off the timing a bit. You will scrafice a little performance but be able to run the cheeper gas.

I am not worried about sacrificing perf but I don't want ot mess with the timing too much right now. Also, that kind of defeats the purpose of the good heads. i have the stock ones still... hmmmmmm



Sorry for the off topic but I don't recall seeing you post in the thread about the bogbash on scugog tomorrow. They don't know me and I'm invited, so you should come.

I posted there. I would love to be there as it is suppose to be +32 tomorrow but I am away at my sister in laws wedding. I am not pleased.

[Lockjaw]

Al told me not to run anything less then super unleaded with any flow with the good heads.

I think if you use good oil 50:1 is fine.

Plus let me ask you this? How do those mechanics make money? By fixing broke stuff. ;)

[PHISH]

How do those mechanics make money? By fixing broke stuff. ;)
that is always in the back of my mind, but I would like to think it isn't true.:o

[NicePackage]

I hate it when other people schedule my summer for me! Friggen weddings, birthdays.

Have you done a compression test with both sets of heads? That'll shed a lot of light on things.

[Action Dave]

Simply put, if you want to run the tight heads, you need at least 91 octane. If that is too much of a hassle, go back to stock heads. Then you can use 87 all day long w/out having to worry.

[Action Dave]

Plus let me ask you this? How do those mechanics make money? By fixing broke stuff. ;)

If you have to worry about your mechanic giving bad advice to get more business, you should look for a new mechanic

[PHISH]

Simply put, if you want to run the tight heads, you need at least 91 octane. If that is too much of a hassle, go back to stock heads. Then you can use 87 all day long w/out having to worry.

This boat is new to me so I am encouraging all the help I can get. What is the horsepower and mph gain with the tighter heads?

[Action Dave]

It really depends on how much compression you are getting with the tight heads. The biggest difference in performance would be on accleration. You might loose a mile per hour or two at the most on top.

[NicePackage]

On my former 2 stroke toys, the top speed wasn't really affected by the heads, it was more the hole shot and mid range acceleration. It was noticable for sure, but it depends what you're used to. Change them before you ride one weekend and you'll maybe never notice.

[Action Dave]

I couldn't agree with you more. If the heads were really radical, you might notice a difference. However, if they are that tight, I don't think 91 is enough octane. OMC+high compression= real fast and then boom.

[PHISH]

Its been recommended to run the higher Octane even if I have the loose heads back on. If I go back to stock heads and expect to pull a skier or put 800lbs in the boat then the old OMC might heat up on the lower Octane due to the heavy load. I might just have to continue with the high comp heads.