57 evinrude 10h.p.

[LCjerk]

I have a few questions i need an answer to. The first question is what is the correct fuel mix for this motor. I assume it is 50:1 but i just want to verify. Another is the motor has an old metal pressurised tank. It has an air line and a fuel line running off the tank and to the motor. And a three prong fuel connector that leaks pretty good. The tank also has some rust in the bottom of it. Is there anyway to convert this to the new evinrude single hose two prong system. I doubt there is but if possible i would like to do so. And last. Is there anywhere i can find another tank or atleast the fuel line connectors both female and male end so i can replace those??

 

[Chinewalker]

Re: 57 evinrude 10h.p.

Hello,
Why not clean up the tank and repair the connector? The o-rings for the connector are about a buck apiece and not too hard to replace. And the top canister assembly comes off the tank allowing you to clean the rust out pretty easily.
If you'd rather convert it, check the sticky post at the top of the Johnrude page...
- Scott

 

[tmcalavy]

Re: 57 evinrude 10h.p.

The OMC recommended mix for a 57 is either 16 or 24:1, can't remember which. OMC didn't go with 50:1 as the standard until the 60's. Give it more oil to avoid problems. Check the top post/thread in the Evinrude/Johnson forum to find out how to do the fuel tank/pump conversion. Costs less than $100 if you're lucky and elimnates the old two-line pressure tanks...if you want to do that. Chinewalker is right though, the older system is just as reliable...just requires some tank maintenance.

 

[Texasmark]

Re: 57 evinrude 10h.p.

2 cycle engines used to use 4 cycle crankcase oil back in the early days (16-1 days) cause there wasn't any 2 cycle oil. Today you have TC-W3 which is a superior lubricant and is made to run at a lower fuel-oil ratio.

Don't be misled by the technology improvement in lubricants. I'd run 50:1 in a heartbeat.

Example, back in '65 I had a McCullough outboard and one day at the dealership I saw 50:1 oil on the shelf and next to it in a can half the size (and red) was 100:1 oil, both made for ALL their (and probably everyone elses.....why would their engines be any different) engines available at the time under the house brand name. So if the difference wasn't improved technology in the oil, what was it?

Mark

 

[Chinewalker]

Re: 57 evinrude 10h.p.

I would NOT run 50:1 in that motor. I've got several blocks here that were run on 50:1 and they all have significant wear to the crankshaft main bearings and the wrist pin bearings in the rods showed wear, too. That motor is only about 50-percent needle bearings - the other 50-percent is bronze bearings which require a bit more oil volume to properly lubricate...
- Scott

 

[pgdignan]

Re: 57 evinrude 10h.p.

Converted my '58 5.5hp from dual line to single using a mikuni pulse pump and some additional fuel lines. Repair your old tank and sell it on ebay, there's a big market for those old pressure tanks and fittings and the fittings alone would probably cover the cost of the upgrade. On one of the previous posts someone had a scanned diagram of how to replace the o-ring assembly on those pressure connections. As for the cost to change from dual line to single, I think the pump cost me about $20 from aircraft spruce and you'll need to get new intake gaskets (not very expensive I bought mine from NAPA) and fuel connectors and probably about 5 feet of fuel line. Good luck with it, I run mine at around 32:1 figuring that the improved lubricity of modern 2 stroke oil doesn't require the initial 24:1 recommendation but I don't think I want to risk the motor running 50:1 (just seems to lean.)

 

[LCjerk]

Re: 57 evinrude 10h.p.

You guys have been very helpful i really appreciate all the input. I saw that the top of that tank came off and would make for easy cleaning i was just scared that when i removed it there may be a gasket or something under there i could not replace. If anyone has any ideas for me on what kind of problems i could run into in removing please let me know. Also i know everyone has different opinions but would it be better to convert or to run as is??

 

[F_R]

Re: 57 evinrude 10h.p.

For every yea opinion on the conversion, you will get a nay opinion. Frankly, if I were doing the conversion, I would do it differently than the Mikuni deal. There IS an easier way. Several, in fact. Evinrude even made an accessory conversion kit. Do it the Evinrude way and keep your motor "original".

Now about the fuel mixture: As you see, thre are many opinions on that too. However, I want to tell you that those pre-1961 10hp motors had a lot of trouble with beating the wrist pins out of the pistons, even with the correct 24:1 mix. Why take a chance on making it wear out even faster?

 

[Scaaty]

Re: 57 evinrude 10h.p.

You guys have been very helpful i really appreciate all the input. I saw that the top of that tank came off and would make for easy cleaning i was just scared that when i removed it there may be a gasket or something under there i could not replace. If anyone has any ideas for me on what kind of problems i could run into in removing please let me know. Also i know everyone has different opinions but would it be better to convert or to run as is??

Laings Outboards has all the stuff required to repair the old tank. Gaskets, hose, etc. The female fittings are pricey, but its usually just the oring's. Pick them out and replace. Run 24-1...NOT 50-1...wrist pin bush's like the extra oil. (I think its a bushed wrist pin anyway..might be rollers, but 24-1 still the best bet

 

[Texasmark]

Re: 57 evinrude 10h.p.

To each his own. It's not the amount of oil perse; it's the oil's ability to provide a film between moving metal parts. Oil that doesn't breakdown (squish out) under high stress loads is the requirement and that is in the chemistry of the product.

Mark