1977 250 SL

[Harvey Mushman]

Recently purchased a 1977 250 SL and have yet to hear it run. The fuel oil pump has been disabled and fuel must be pre-mixed. What is the suggested ratio, please? Thanks! (still waiting to get an owners manual)

[viclioce]

assuming it's not going through a break in period, a 32:1 with a good grade synthetic 2 stroke oil is usually recommended. Stick with non-ethanol 91 octane or better! ; D Victor

[dirty_rat]

Wow, a famous name from "On Any Sunday"

[Darrell]

What D. Victor said...

I was running a 35-36:1 ratio with 94 octane, mainly because that lean mix is what my 94 Wombat required or else it would foul plugs.

However, I've been getting exhaust side piston and cylinder scuffing using that ratio with my 250SL - so now it gets a 32:1 mix (Yamalube 2R, or Lucas semi-synthetic), and I've also dropped the needle clip a notch.

[Harvey Mushman]

Thank you for the advice. Any tips on getting a frame color number? It is the dark blue used on several models. I'd like to find (or have mixed) a can for touchup application by brush.

[Harvey Mushman]

Okay, new question...My 250 SL (white tank with a blue stripe) has a cracked oil tank. Is there a way to remove it, short of pulling the engine.
Next question, is there a best way to by-pass this system and plug all the connecting oil lines? I have yet to confirm the pump is disabled (or even there?) but the plan is to just run it on premix...for now at least. Thanks!

[Darrell]

I think you have to at least remove the head to get the oil tank out. Otherwise, If the tank is a total loss then maybe chop it up into smaller piesces with a Sawzall/reciprocating saw.

As for the oil pump, probably best to remove it and forget about it. SH has oil pump blank covers to cover the PTO hole.

[Harvey Mushman]

Thank you!