Prop stolen, need help determining size/pitch

[rbezdon]

Though not new to iBoats, I am new to the outboard forum. I have two boats, an I/O and an Outboard. have had MANY more issues with the I/O so I have not needed to post here before!!<br /><br />My issue is that I have been running my 15' 78 Arrow Glass Tarpon with its 78 Evinrude 55HP for a couple of years problem free. Yesterday we went to use it and it wouldn't go in gear. The boat has been in the water so we didn't notice but the prop and all of the hardware was gone!! I know to determine the best prop we need the WOT RPM but I have no tach and no idea what RPM it was getting to. Since I had trouble free operation I also never pulled and checked the prop size and pitch. Does any one know what size and pitch came standard on this engine?? At least if I can get the right diameter it is a start.

 

[CATransplant]

Re: Prop stolen, need help determining size/pitch

If you click Propellors near the top of this page, you'll go to the iboats propellor finder. That will give you a range of pitches suitable for your outboard. Problem is that it won't help that much picking a prop for your situation. You may want to cunsilt a local dealer.

 

[rbezdon]

Re: Prop stolen, need help determining size/pitch

Thanks for the input. Just as I already knew, every one wants to know "what I am running with now and what are the WOT RPMs. I did find the onwers manual and it seems to say the original engine was supplied with a 12 1/4 x 15 3 blade Aluminum. Does this seems reasonable?? The boat is roughly 900 lbs (fiberglass is heavy). I think I am going to just buy one of these as a starting point. What is the best way to get the WOT RPMs on an outboard?? Can I use my automotive tach??

 

[rbezdon]

Re: Prop stolen, need help determining size/pitch

Also, does anyone know what the prop mounting kit should include?? Thrust washer, cotter pin, nut (size/thread??) etc. and where I can get a complete kit??

 

[CATransplant]

Re: Prop stolen, need help determining size/pitch

I was going to suggest the 15" pitch prop. I think it should work pretty well with your boat. If you buy the aluminum one, it won't be too expensive, so if it doesn't work perfectly, you can keep it as a spare (a good idea in any case).<br /><br />I don't have the details on the attaching hardware, I'm afraid. You can go to the ishopmarine.com site, click Parts Lists, then drill down to your model. When you get there, click to see the Gearcase Group, and you'll see all the parts in an exploded view, with part numbers adajacent in another window.<br /><br />With the part numbers, you can pretty much go to any Johnnyrude dealer and get the stuff right there. You can get the prop there, too.<br /><br />You might find a better prop than the stock one, but without a starting point, you might as well start with the 15".

 

[rbezdon]

Re: Prop stolen, need help determining size/pitch

Started calling around to some local dealers as well and got a prop specialty shop about 10 minutes from where I keep the boat. They recommended the 15 or 17 and they had the OEM Johnntrude 17" in stock for $103. iBoats was 93 plus shipping so almost a wash and I get it right now!! They also had the prop nut kit ($8)and the thrust washer. That thing was $31 bucks!!!! Seems I'll have it back on the water in a couple of hours. Any ideas on how to hook up the tach to check the WOT RPM?? Do I need a special 2cylinder tach and where can I get at the ignition coil connections to hook it up?? A lot easier on the I/O where it just hooks on the coil - like a car and I cn use my automotive test tach.

 

[CATransplant]

Re: Prop stolen, need help determining size/pitch

Ask while you're at the dealer about tachs. They'll have them there and will be able to advise you for sure. Marine tachs are different from auto tachs, so you'll end up getting one at the marine supply place anyhow.<br /><br />I'd go with the 15" prop, though. If it's underpropped with that, then get the 17" and keep the 15 for things like water skiing and running when you're heavily loaded. I think everyone should have a spare prop on board anyhow. But take the advice of your dealer. You can always back off to the 15" prop if you buy the 17.

 

[rbezdon]

Re: Prop stolen, need help determining size/pitch

Thanks CAT. By the way, how you like livin in the land of 10000 lakes?? Looks like you moved there from Calif. I used to live in Eden Prairie back in the day when the Twins were World Champs and the Vikings were just learning how to take advantage of a guy named Randy.

 

[CATransplant]

Re: Prop stolen, need help determining size/pitch

I like it just fine here. About 10 lakes within 20 minutes of my house, and a small lake about three blocks. Yesterday, I went to the small lake after supper, and caught a 24" Northern Pike. I'm having it for supper tonight.