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15:1 or 32:1

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For break in? Yamaha reccomends heat cycle so imma do that for the break in but they also reccomend using a premix of 15 to 1 i mean i know that sounds excessive....ive got 1/8th of residual oil in my case so im sure i am okay on the lube part but i just want to ge6t some other opinions thanks a ton guys

P.S. I turned into a troll a little bit once i got a streetbike but this summer i plan on returning to my dirt roots a bit

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Run whatever ratio you normally run. There is no need for more oil during the break-in procedure.

agreed. if it is jetted for 32:1 and you put in a ratio of 15:1 that is kinda pointless dont you think ? Break it in with your normal ratio

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What he said.

Just take it easy on the bike for the first tank or so. Don't fire it up and then rip it.

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Here is one part I really do not understand. If 15:1 is better for a new engine, as Yamaha clearly states, should we not be using this all the time? Just trying to follow their logic.

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There is know reason to run 15-1 to brake in you're engine.Ive always used 32-1 or 40-1 with know problems.I agree with rcannon,if its so good to use 15-1 why not use it all the time.Another thing,I guarantee you no professional engine builders are using 15-1 on break in.

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It is just for extra lube for the lower suport bearings, and lower rod bearing, for the first revolutions of the motor while breaking in, which should only take about 5 min. a good cool down is just as important, then drain the rich mix out, and let'er rip!:confused:

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I was talking to an ex-factory mechanic and he said when they were running horsepower tests that somewhere around 8:1 gave the best horsepower in the YZ's, but he recommended that I run 32:1, it's cheaper and you don't have to go nuts with your jetting.

I'm not saying that HP is everything , just some pointless info I thought I'd throw out :confused:

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What he said.

Just take it easy on the bike for the first tank or so. Don't fire it up and then rip it.

On my new Gas Gas the dealer/owner, 40 years bike mechanic, told me ride it like I stole it at the beginning for proper break in.... He advised do not baby it.

Here is one part I really do not understand. If 15:1 is better for a new engine, as Yamaha clearly states, should we not be using this all the time? Just trying to follow their logic.

15:1 is crazy. Im running 50:1 with OPTI-2 pre mix. 40:1 was rediculously too rich with that stuff even, but it's a lot different than the premixes you guys use.

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I think I will end all of this talk of mixtures. If gasoline goes any higher , I think i will start running 1:1 and save a bunch of money. Plus, if 15:1 was actually depositing extra oil in the lower end (more than your using) it would eventually fill the low end any you would have real problems.

If you really think about it any benefit from extra oil would be negated by the extra heat of running such a gas lean mixture. I dont want to sound like "this is the final word on this"...I love the topic and want to see what everyone else thinks.

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coop,I understand your logic on extra lube for the bottom end,but I still think the 15-1 is not needed.Also, theres something that hasnt been mentioned here and that is the fact that when you run a mixture at 15-1 your actually leaning out the mixture which seems like it would require some jetting changes.Some people think by adding oil you richen the the mixture,but its not true.15-1 is richer with oil ,but less( leaner )fuel which is some ways cant be to good on your engine.I know people are only running the 15-1 for a short time,but I wouldnt do it.I ran 40-1 for years until I had some engine work done on my 97 yz250 by a well know engine builder and he said 32-1 is the best ratio to use.Ive used 32-1 since with no problems

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Thanks a ton guys, Never did I imagine such a turnout with info.

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less (leaner) fuel which is some ways cant be to good on your engine.

The quickest way to destroy any engine (2t or 4t) is to run it in an extremely lean fuel condition.

Anytime you do performance hop-ups, you need to address the amount of fuel that you are getting into your cylinders.

The first thing that you do when adding NOS to a car, is increase the fuel when the NOS is sprayed. Not doing this will cause all sorts of very bad damage to the pistons, heads, valves, etc, etc, etc.

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I think I will end all of this talk of mixtures. If gasoline goes any higher , I think i will start running 1:1 and save a bunch of money. Plus, if 15:1 was actually depositing extra oil in the lower end (more than your using) it would eventually fill the low end any you would have real problems.

If you really think about it any benefit from extra oil would be negated by the extra heat of running such a gas lean mixture. I dont want to sound like "this is the final word on this"...I love the topic and want to see what everyone else thinks.

Not sure you will save money just yet. Pre-mix is about $35/gallon and gas is slightly less....for now.

I appreciate this discussion though as I will be breaking in the new beast very soon. Having searched this forum and others, I have found that break-in procedures and mixing ratios are clearly established with a solid foundation built upon hearsay, well known but unnamed engine builders, and unexplained experiences. What are we to follow?:confused:

I just bought some R-50 and Klotz says 40:1 for their oil in a 250cc engine. Good ratio for MX?

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I have found that break-in procedures and mixing ratios are clearly established with a solid foundation built upon hearsay, well known but unnamed engine builders, and unexplained experiences. What are we to follow?:confused:

You know, you really can't go wrong following the manufacturer recommendations for breaking in a new or rebuilt bike. Worst case scenario you oil foul a plug or two.

I just bought some R-50 and Klotz says 40:1 for their oil in a 250cc engine. Good ratio for MX?

I run Castrol 32:1 in my 490, but that is just my preference (don't oil foul plugs, very little smoke, and no spooge out the end of the pipe). I don't have any data to back it up, and the manual recommends 24:1 Yamalube or 20:1 when using anything else.

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Run whatever ratio you normally run. There is no need for more oil during the break-in procedure.

i agree also, ive never changed my ratio for breakin!

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Plus, if 15:1 was actually depositing extra oil in the lower end (more than your using) it would eventually fill the low end any you would have real problems.

Wouldn't the excess oil build up to a certain level and then just be sent out the exhaust (either through the combustion cycle or ???). I mean a 2t isn't the same sealed combustion chamber a 4t is.

Once the intake and exhaust valves close, everything in the cylinder is either going to compress, be forced past the rings, or hydrolock.

A 2t, on the other hand, doesn't use valves to seal the combustion chamber. It uses the piston to cover and unmask the intake and exhaust ports. As long as one of set of them isn't completely covered by the piston, there is an "outlet" for any excess oil. Of course, once they are covered, you have the same options of a 4t.

But a 4t may have something approaching 90 degrees of crank rotation on the compression stroke from BTC to TDC(with the cylinder sealed), a 2t would have considerably less. The exhaust port isn't closed by the piston until what, 45 degrees before TDC?

I guess, I am trying to say that a 2t will have much more opportunity to expell excess liquid (oil in this case) without hydrolocking.

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I appreciate this discussion though as I will be breaking in the new beast very soon. Having searched this forum and others, I have found that break-in procedures and mixing ratios are clearly established with a solid foundation built upon hearsay, well known but unnamed engine builders, and unexplained experiences. What are we to follow?:confused:

A couple of the engine builders that Ive dealt with in the past are Terry Varner from Varner motorsports and Tom Morgan from Tom Morgan racing.Terry recommended 32-1 ratio and if I remember right Tom recommened the same.This is not hearsay this is fact:prof:

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