92oct. vs 87?

[sunman]

My 20ft Pontoon w/83' 50 hp. Johnson calls for 92 oct/gas. The way gas is going up, I'd like to run the 87, I mainly just putt around the Suwannee River, not too much WOT!<br /><br /> If the Timing is 19-21, what should I set it at inorder to run 87 oct.<br /><br /> PS: I have never ever had any cooler keep Ice, "Ice" for 5 day's I keep opening it up, and go fish'n for a COLD 1

 

[Dhadley]

Re: 92oct. vs 87?

Are you sure it calls for 92? I dont recall seeing an OMC that calls for that in the US. Some international models may as they rate their fuel differently.

 

[rickdb1boat]

Re: 92oct. vs 87?

Run the 87 and you will be fine... Fuel has changed a lot in 20 years and that may have been the recommendation back then.

 

[sunman]

Re: 92oct. vs 87?

I believe I saw it the factory repair manual, in any event a friend that is "Factory trained in S.D.Calf." and was passing through Fl. said "We turn the total timing adjusting screw in 4 turns" that will allow you to run 87#<br /> He did it while I was at work, do I leave it, as I only putt around the Rivers, or change it back 4 turns, and set the plugs at .040, and run 87#<br /> BTW, I just look'd at my plugs, w/2 days on'em an the ignition line on the ground electrode is just about in the middle of the 90 deg bend. In racing we use that line as a guide to the total timing that the engine will tolerate vs a timing light only method, You all ever use this method?