'86 Johnson 50

[fishnfun]

First off, great board.<br /><br />I have a '86 50 Johnny VRO(disconnected)on an 18' Lowe Fish-N-Fun pontoon. I am looking for a prop. Currently runs ~5200 rpm WOT with 3 people and gear with OEM 12 1/4 X 15.<br /><br />I know that some of the older engines in this class (2 cyl, small gear case) have a range of 5000-6000rpm and most (and I am guessing this one) are 4500-5500rpm. I have talked to several local shops and have yet to get a definitive answer. The locals don't seem to be Maggot Motors, but not the most helpful either. Therefore I intend to order the prop and motor manual and not grace them with my money.<br /><br />I usually cruise around 4500, but when pulling a tube (well it DOES say Fish-N-Fun) have to basically run WOT. I am thinking of a Hustler 12 1/2 X 13 but would like to know the specifics of this engine before I commit.<br /><br /><br />Can anyone give me the specs for this? Any comments on this line of motors welcomed.<br /><br />Thanks<br />fishnfun

 

[JB]

Re: '86 Johnson 50

Hi, Fishnfun. I particularly like the JohnnyRude inline loopers, but they don't like to be over-revved. I fear a 13" prop would result in over-revs in an incautious moment. You currently rev very near the 5500rpm level and a 13 would theoretically put you at 5600 with normal load. Too high.<br /><br />Perhaps a Hustler 13 or a cupped 13 or even a Comprop 4 blade 13 would still be safe, but I wouldn't do it if it were my motor UNLESS I used that prop only in heavy-load situations and went back to the 15" for normal use.<br /><br />Red sky at night. . .<br />JB

 

[fishnfun]

Re: '86 Johnson 50

Thanks, JB<br /><br />So you are saying that the operating range for this engine does top out at 5500rpm? I think I may go with a 15 pitch.<br /><br />I picked up a Stingray hydrofoil off ebay and will try it. May not do any good, but what is $30 in the boating world?<br /><br />Thanks,<br />fishnfun

 

[texacana]

Re: '86 Johnson 50

Hey fishnfun, I have a 1985 50HP Evinrude and it came with a 12 1/4 x 15 stainless steel prop. With my 15 feet Skeeter I was doing 35mph at wot. I replaced it with a Hustler aluminum props 12 1/4 x 15 and I'd gained 4 more mph. Then I bought another hustler props this time I went to 11 3/4 x 17, I didn't gain anything. As a matter of fact I lost on take off, my boat takes a while to plane after I went to 17 pitch. So I went back to 12 1/4 x 15. MY stainless steel prop is at the repair shop right now getting fix and cupped. When I get it back I'll let you know if there's any difference.<br /><br />Good luck to you!

 

[fishnfun]

Re: '86 Johnson 50

texacana, thanks for the info. What kind of difference in rpms did you see when going to the hustler 15 from the oem 15.<br /><br />fishnfun

 

[texacana]

Re: '86 Johnson 50

fishnfun, My rpm gauge is not the most accurate in the world. I installed an automotive tachometer. The rpm stayed the same around 5500 since the pitch are the same (15).. You'll probably be better off if you stayed with the same size prop and just have it cupped... MY stainless steel is very heavy.. It's probably four times heavier than the hustlers.. Could be why I gained 4 mph... Good luck!!