How Low Can I Go?

[joey nathan]

On oil-fuel mixture that is! 1975 70HP Evinrude. Runs very well, however I'm thinking of backing off on the 16 ounces of TC oil for each 6-gallon tank.

Significant smoke when idling, and if I'm trying to fish while idling and the wind is from the stern it is pretty bad. Can I safely go with say 2-3 ounces less per tank without harming my vintage 'Rude?

Thank You in advance for any and all wisdom...

 

[jimdd810]

Re: How Low Can I Go?

I wouldnt 50:1 is where you need to be. Firts try a decarb on the engine. Sounds as if your burning to rich it may be time for a carb rebuild.

 

[kenmyfam]

Re: How Low Can I Go?

Stick with the recommended mix. Decarb is a great idea.
Would you run your car with less oil than it should have in there ?? Do you keep the brake fluid level deliberately low ???
Hope you see where I am going with this one.
You are asking if it is O.K. to run with less lubrication !!!!

 

[tx1961whaler]

Re: How Low Can I Go?

Decarb.
Then run 50:1 with a full synthetic oil.
Also, make sure the thermostat is operating properly.

 

[Chris1956]

Re: How Low Can I Go?

The gas-oil mix for Two cycle motors is calculated for WOT usage. Motors used at lower RPMs can use less oil in the gasoline. So can you add less oil to the mix w/o damage? Yes, but only if you keep the engine speed down.

You could easily run 100::1 if you stay at idle. If you remember, OMC built variable ratio oiling (VRO) units on their early oil injection motors.

You could mix one tank at 50::1 and run to the fishing spot. When you switch to idle speed, switch tanks to a 100::1 mix. Of course if you forget to switch back to the 50::1 when you want to leave, you may have problems.

 

[Lion hunter]

Re: How Low Can I Go?

2-3 ounces less is gonna put you around a 55:1 ratio. I doubt it would make that much difference in the smoke at idle at the risk of harming the motor at WOT. Those big 2 strokes don't like to be lugged around. My 60 will only go about 15 min before it starts loading up and running erratic. Get a cheap electric or a kicker and you be much happier.

 

[kenmyfam]

Re: How Low Can I Go?

I agree completely with the VRO statement however I would not like to have the bother of remembering which tank is which or the hassle of changing tanks for different purposes. Fried motor waiting to happen in my humble opinion.

 

[jimdd810]

Re: How Low Can I Go?

yep what he said!

 

[F_R]

Re: How Low Can I Go?

Use Pennzoil 100% Synthetic TCW-3 outboard oil at the correct 50:1 ratio. Great stuff and smokes less. Less oil sheen on the water too. And bio-degradeable. It's all I use any more. I get it at Wal-Mart.