# Oil mixture ratio '76 Yamaha Exciter 340



## bassman3006

What is the proper "mix" for these sleds. The oil injection has been removed, and I cannot find any literature that supports the idea. Right now I'm doing 50:1 Amzoil Saber. It seems a bit rich...but I don't wanna burn it up.


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## Burksee

Way back when 40:1 is what we used to run most of the time. When using todays oils, especially synthetics like Amsoil, Klotz, Marble, ect you can run at 50:1 all day long. Amsoil Saber is a very concentrated oil, for snowmobiles we've run their Interceptor oil as you can pre-mix it or use it in an injection system.

keep an eye on your spark plugs, they'll tell you everything you need know about how its running. If you think its running to rich jetting should be checked and adjusted. If your going slow, trail riding a leaner jet/mixture may be in order to help not fouling out plugs but if your running WOT very much it could result in a lean condition/melt down.


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## roger23

I had a 76 ,,440 I ran 50 : 1 Castrol snowmobile oil ,,never a problem ,,ran it for years ice fishing, until a couple years ago when the undercarriage rusted away,, lack of maintenance


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## sourdough44

Usually 50 to 1 with those machines, as in my 1980 John Deere(gone now). Some of the Amsoil stuff is O.K. at 100 to 1. So if just run of the mill mix I'd go with 50.


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## bassman3006

Thanks for the info. It's running great...just seems a bit smoky at times. Us newbies just need someone to reassure us we are going about things the right way sometimes! Thanks Again!!!

Bassman


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## sourdough44

With the choices of a yearly plug change or possible engine damage, I'll err on the side of the plug change. You could try some of that 100/1 Amsoil mix too. I've used it in my older John Deere & a few other things without problems, mixed 100/1. You can also mix it a bit on the richer side if desired.


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## roger23

I think a lot of people are so use to the new machines ,with no smoke ,,don't remember the good old days,,remember oil is the lubricant for the engine,,,once you damage the engine you can't fix it by adding more oil ,,,to late,,,stick with what works,,,I never tried Amsoil 100:1 but I have heard a lot of good reports ,,

Here are a couple pictures of the neighbors snow blower piston,,his wife did not like the smell of smoke he leaned out the mixture a little too much


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## ESOX

For 6 years I ran the snot out of a '77 440 at 75:1 with Amsoil. I had heard of people running it at 100:1 but just didn't have the guts or cash to be the test dummy.

BTW, those are great sleds for the technology available back then, very reliable as long as you left them stock. Try to mod them even a little bit and they get ornery and unreliable.


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## bassman3006

Those pistons look like they got a bit warm. YIKES! I'm good with the smoke. That's a good sign. I love the smell of 2 stroke in the morning. I haven't heard anyone knock those old yammies yet. For $100 I couldn't go wrong!


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