fuel/oil ratio question.

[smokeybacon]

I recently purchased a 10hp 1957 Johnson Seahorse. Model number QD-17. The previous owner said he had the powerhead rebuilt a couple years back and also installed new coils and points. <br />My question is, do I still need to run an oil fuel mix of 24:1 like the manual suggests, or can I run it on leaner 50:1 ratio since it has been rebuilt with new components. It smokes quite a bit when I run it in the tank at 24:1 and I'm wondering if a 50:1 would remedy this.<br /><br />I also noticed that one of the coils has a small crack in the casing. Should this be replaced right away or am I ok to go out on the lake the way it is?<br /><br />Thanks for any info.

 

[Josh Knapp]

Re: fuel/oil ratio question.

i think J/E is saying to switch to runnning 50:1 on these motors now. I always have. unless the fuel line has the three connectors on it where you have two hoses going down to the fuel tank. then I am not sure I have run 50:1 in those but I am not sure if it is good for those or not. as for the coil I would replace it. a crack in the casing is a sign that it will break down on you it just doesnt say how long before it does. just my $.02 <br />josh

 

[DJ]

Re: fuel/oil ratio question.

Smokey,<br /><br />50:1 was recommended in J & E engines after 1963. Those later engines were fully "jeweled" meaning they were all roller type bearings.<br /><br />I'm not sure about your engine. <br /><br />I have a 1957 7 1/2 that I run at about 35-40:1.<br /><br />I also run synthetic or partially synthetic oil. That cuts down on the smoke considerably. It's expensive, but you're not going to use enough of it to make a big differnce.<br /><br />Replace the coil. It will fail at the most unopportune time.

 

[Paul Moir]

Re: fuel/oil ratio question.

If the ignition coil has a crack in it, I would replace it. They're cheap. I find it odd that such a new coil would have a crack in it. You can get a new one from NAPA, PN 18-5181, should be around $20. Iboats has 'em too.<br />Your engine will, however, run on one cylinder. <br />Before wrenching your engine, get ahold of a service manual and read it. You can get an aftermarket one from Iboats, or perhaps borrow one from the library. You can still get OEM ones, and many here consider them superior:<br />TheOutboardWizard<br />Mastertech<br />Marine Engine<br />Ken Cook <br />Sometimes you can find a used OEM one on ebay for a fraction of the price of a reprint.<br /><br />On the subject of oil mix, first let me tell you that that is a contraversial subject here! Although many have had success running pre-'64 Johnny/Rudes at 50:1, your engine is not a good candidate. It employs a number of babbitt bearings in the powerhead, and I belive it also employs an oil slinger rather than a proper oil seal for crankshaft sealing. The oil slinger requires more oil to seal properly.<br /><br />EDIT: Looks like you beat me to the punch this time DJ. I was wondering if richly mixed synthetic would cut down on smoking...

 

[DJ]

Re: fuel/oil ratio question.

Paul,<br /><br />It seems to for me. I can notice a difference.