100:1 mix ok in Yamaha 1999 3hp?

[cprodave]

My recently-acquired near-mint condition Model 3MSHY (transom plate is marked 3MSHX--but i cant find parts diagram for 3MSHY) has a decal indicating 100:1. I know OMC did 100:1 for a couple years with bad results, went back to 50:1.
Anybody aware of problems that eventually resulted on single cylinder Yamahas running 100:1? First sea trial we are going to run 75:1 Johnson Evinrude Premium Oil (but not synthetic) and non-ethanol gas (until we can find some Yamaha oil).
Or would it be best to use 75:1 (or 100:1) full synthetic? Running in water tank for less than 5 minutes motor smoked a lot, but might not have been warmed up yet

 

[tpenfield]

I have a similar engine and run 50:1 . . . I don't know if I would trust 100:1 even though it is specified.

 

[cprodave]

Thanks for quick response recommending 50:1

Please disregard comment about 3MSHY vs. 3MSHX, it seems both might be valid Model Numbers .

 

[Sea Rider]

100:1 might be fine for long trolling purposes, once opening the throttle up will need 75:1 or 50:1 if preferred.

Happy Boating​

 

[boscoe99]

Many Yamaha two strokes in the smaller HP are rated for 100:1. Not a typo. You think that Yamaha is going to offer a recommendation that might be damaging to the motor and their reputation?

Many nervous nellie's might run 50:1.

I suppose there are some that will run 25:1. On the theory that more has to be better.

 

[boscoe99]

Thanks for quick response recommending 50:1

Please disregard comment about 3MSHY vs. 3MSHX, it seems both might be valid Model Numbers .

Same motor. Just a different year. Y = 2000. X = 1999.

 

[cprodave]

Thanks all for the input. Currently running it at 75:1.

 

[99yam40]

just what I have read before, but
long lay up of the motor run at 100 to 1 might let rust sneak in during that no run time

 

[ct1762@gmail.com]

100:1 is fine for normal operation, but only if you use it often. never lay it up with only 100:1 film coating the bearings and cylinder walls.