78 mark twain ob with 78 evinrude 115

[78twainer]

I can try to find more info on weight and stuff, but it's a old heavy fiberglass boat. Wat do I need for a prop. Good all around. Will be towing kids on tube and fishing occasionally. What prop would u suggest?

 

[Scott Danforth]

at the top of the forum are 3 stickies http://forums.iboats.com/forum/general-boating-outdoors-activities/prop-questions-and-topics

most importantly is the one listed as "read this first"

ESSENTIAL DATA REQUIRED
When posting a question about propellers, you cannot get a reasonable answer unless you provide the following information in your post: Items 1-4 are essential for meaningful response to most questions.
1) Performance issue you are trying to correct.
2) Current prop manufacturer, model, aluminum or stainless as a minimum.
3) Current prop diameter and pitch (required).
4) Wide open throttle RPM and speed with an average load (very helpful)
5) Engine/drive make, model, year, and HP
6) Boat make model, year, length and weight

most importantly items 1-4 need an answer

here is a link to the mark twain specs (you didnt specify a model) http://boatspecs.iboats.com/Mark_Twain__1978/bp/34br1283s0y

here is a link to the engine specs http://boatspecs.iboats.com/Evinrude__115hp__1978/bpe/35br2231hy (there are three listed)

 

[ezmobee]

14x17 would probably be a good start.

 

[78twainer]

at the top of the forum are 3 stickies http://forums.iboats.com/forum/general-boating-outdoors-activities/prop-questions-and-topics

most importantly is the one listed as "read this first"

ESSENTIAL DATA REQUIRED
When posting a question about propellers, you cannot get a reasonable answer unless you provide the following information in your post: Items 1-4 are essential for meaningful response to most questions.
1) Performance issue you are trying to correct.
2) Current prop manufacturer, model, aluminum or stainless as a minimum.
3) Current prop diameter and pitch (required).
4) Wide open throttle RPM and speed with an average load (very helpful)
5) Engine/drive make, model, year, and HP
6) Boat make model, year, length and weight

most importantly items 1-4 need an answer

here is a link to the mark twain specs (you didnt specify a model) http://boatspecs.iboats.com/Mark_Twain__1978/bp/34br1283s0y

here is a link to the engine specs http://boatspecs.iboats.com/Evinrude__115hp__1978/bpe/35br2231hy (there are three listed)

I read em already and said I'd get more info... it was almost 11 at nite and I was in bed. I'm sry. I grew up on the river but never had owned or maintained a boat myself. I have tried looking at prop to see if there are any markings or stamps on it. But I didn't see any. Do I need to take the prop off to determine pitch? There is currently no real issue with the one I have I'd just like a new one and use the current as a backup on board just in case. I've never taken the boat out in the water so I can't tell ya much about rpms at wat speed or anything...sry for wanting my boat to be ready and safe pre boat season.

 

[Sea Rider]

Bad idea invesing on same new prop when current one has no data whatsoever. Remove prop, take to a prop shop to have it measured. Install a induction tach and go for a wot run as currently loaded. Report max wot rpm achieved. check if al least middle to max wot rpm factory range. From there can maximize a less prop pitch for OB to run happily at max wot range.

Happy Boating