Proper gas/oil ratio? Also gear ratio on this motor?

[josh_scci]

I have a 2 cylinder 2 stroke 1988 40hp Johnson. I am thinking it should be 50:1 but not sure my dad whose boat this was before passing was told 80:1 buy a mechanic when he had to bypass the automatic oiler when it quit.

And does anybody know the gear ratio on this motor?


Also what would be the best way to clean out the old metal gas tank?

 

[Travis798]

Re: Proper gas/oil ratio?

Re: Proper gas/oil ratio?

It's just a guess, but I'm going to say 50:1. There's no way I'd mix anything 80:1. Remember 80:1 is less oil than 50:1. 50:1 is 50 parts gas to 1 part oil.

As far as cleaning out old gas tanks, I've always used marbles/bearings/etc. Put them in with some fresh gas, slosh around a while, repeat. I'm sure there's a better way, but it's always worked for me.

 

[josh_scci]

Re: Proper gas/oil ratio? Also gear ratio on this motor?

Anybody got an idea on the gear ratio on this motor?

 

[josh_scci]

Re: Proper gas/oil ratio? Also gear ratio on this motor?

Anybody know this and is sure of the gas/oil mix ratio?

 

[trendsetter240]

Re: Proper gas/oil ratio? Also gear ratio on this motor?

Anybody know this and is sure of the gas/oil mix ratio?

I'm not sure on the gear ratio but I would guess it is 2:1.

I am however 100% certain that your fuel mix should be 50:1.

Cheers.

 

[wilde1j]

Re: Proper gas/oil ratio? Also gear ratio on this motor?

50:1 TCW-3. Don't know the gear ratio. Would be in owner's manual.

 

[ezeke]

Re: Proper gas/oil ratio? Also gear ratio on this motor?

Probably 2.42:1, or 12:29 propeller gear ratio in your manual.

 

[rjezuit]

Re: Proper gas/oil ratio? Also gear ratio on this motor?

I believe 14:27. (1.93:1)Rick