What mixture.

[Franki]

Hi Guys, <br /><br />I have always mixed my fuel at 25:1 with standard unleaded (australia)<br /><br />Thats fairly low octaine fuel, but it seemed to work well enough.<br /><br />What mixture do you guys run?<br /><br />I get the feeling 25:1 is alittle to much oil.. I used to use 32:1 with my motorcross bikes, and I was wondering what the standard is for outboards..<br /><br />I have a 1972, 100HP Johnson V4.<br /><br /><br />rgds<br /><br />Frank

 

[62_Kiwi]

Re: What mixture.

Hi Franki, the standard mixture is 50:1 however I have no specific knowledge of your engine's requirements.<br /><br />In NZ our standard grade is 91 octane whereas in the states I believe it's 87. I imagine yours would be similar to ours ?

 

[Franki]

Re: What mixture.

ohhh, that would explain why I have a trail of oil down the leg, thinking maybe 25:1 is definatly to much oil.. and my engine is probably now hard to start from too much carbon in the plugs.. (only just got this motor 2 weeks ago..)<br /><br />I think our standard unleaded is 87 and our premium is 91 ish... <br /><br />rgds<br /><br />Frank

 

[Franki]

Re: What mixture.

just did some checking, our premium grade is 98 octane.. couldn't find out what standard was though.<br /><br /><br />do you use premium or standard?<br /><br />the difference is about 7 cents per litre here.<br /><br />rgds<br /><br />Frank

 

[62_Kiwi]

Re: What mixture.

Hi Frank<br /><br />Yes you could be right that the extra oil could be gumming up your plugs. 25:1 is generally used for breaking in new engines (first 10 hours).<br /><br />I use standard/regular which over here is 91 octane. Our premium grade is 96 but I'm fairly sure that Australia and NZ use the same fuel types.<br /><br />91 octane is closest to OMC's recommended and I don't think you get any extra performance out of 96, so you will be able to save on fuel costs there.<br /><br />I've noticed in my engine's operation manual that OMC had a product called "Carbon Guard" - I've never tried it and and am not sure if you can still get it. That or something similar might help with any carbon buildup?