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what is gas to oil mix ration on a 89 yamaha ysr 50

Started by fed585, May 27, 2009, 03:51:44 PM

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fed585

i need to know what this is people please help me out
G-fed
#554 ASRA
#554 CCS

Doctor

Wisconsin SportBikes Racing Team, Zone Photo, Dunlop, MotoVid.com, Blackhawk Farms Raceway

Jim Lilly
CCS Ex #703

Super Dave

Quote from: resuscit8u on May 27, 2009, 05:53:46 PM
I believe those are oil injected.
I'm with Jim on that.  Should be a clear reservoir there someplace.  Can't remember if it's under the tail or where.

If it doesn't have it, it has been removed.  Then, I'd start at 32:1.  You could add more and get more power (20:1), but you'd want to increase the jet size to maintain your air:fuel.

You just got it?  How much?  Hopefully a good price.
Super Dave

fed585

no ive had this thing for ages my dad bought it brand new in 89 and now i have it and i ride it around in the pits at the mid atantic races while he races. but he forget the mixture for it so i posted this thread it is so loud man because he got rid of the stock pipe and but a aftermarket one on along with alot of other things
G-fed
#554 ASRA
#554 CCS

Noidly1

Can't go wrong with 32:1. Best all-around ratio. 1/2 cup per gallon.

Sorry Dave but 20:1 will smoke like a sive and kill power.
For best power, run the least oil but, don't expect it to live long...
'08 R6, CCSGP44EX

Super Dave

Quote from: Noidly1 on May 28, 2009, 11:11:17 PM
Sorry Dave but 20:1 will smoke like a sive and kill power.
For best power, run the least oil but, don't expect it to live long...
Best power is actually at around 13:1.  Even Rich Oliver ran 20:1 on his TZ250's when he was beating everyone.  20:1 is generally a really good compromise that doesn't foul plugs as bad.  A two stroke can still run with a 6:1 ratio.  It will struggle, but it will run.  Finally, the only concern IS life of the engine.  Smoke is only a proper byproduct.
Super Dave


Woofentino Pugrossi

32:1 is whats recommended for premix in a YSR 50.
Rob
CCS MW#14 EX, ASRA #141
CCSForums Cornerworking and Classifieds Mod

Noidly1

Quote from: Super Dave on May 29, 2009, 05:35:00 AM
Best power is actually at around 13:1.  Even Rich Oliver ran 20:1 on his TZ250's when he was beating everyone.  20:1 is generally a really good compromise that doesn't foul plugs as bad.  A two stroke can still run with a 6:1 ratio.  It will struggle, but it will run.  Finally, the only concern IS life of the engine.  Smoke is only a proper byproduct.


oil doesn't burn as fast as gas, so yes, it will slow you down.
'08 R6, CCSGP44EX

Super Dave

#9
Quote from: Noidly1 on May 30, 2009, 06:42:52 PM
oil doesn't burn as fast as gas, so yes, it will slow you down.
Well, how many btu's does two stroke oil have?

Next, one will have to recognize that as lubrication goes down, friction increases.  I'm not going to make your decision for you, but I will not support your push.  Might be worth looking at yourself and certainly many others used to try going short on the mix ratio but changed.
Super Dave

Noidly1

BTU's? Heck, I don't know...

While yes lubrisity does go down at higher ratios, there is a sweet spot between wet and slow.

Here's a good Q; What ratio do all of the fast dirt racers use? Bet it's at least 32:1.
'08 R6, CCSGP44EX

Super Dave

Well, they are on four strokes. 

I'm not gonna help you anymore.  You've got your ideas. 
Super Dave