Best Prop Size For Johnson 140 4-Stroke

[glastron50gl]

Re: Best Prop Size For Johnson 140 4-Stroke

Who makes the Prop??? What is the prop number? Thanks Nutinbitin

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

It's a Michigan Match prop, 14" x 15p. It works great, I was pulling 2 tubes with 2 people on each one, could not do that before. Put up the enclosure today (thought it was going to rain) was still able to do 31 mph with me 2 teens and full tank of fuel. Main thing is to see where your wot rpm's are and go from there. mine were way too low before, and I had to wait a while for the 14" diameter prop to be back in stock, did'nt want to go with a smaller diameter than what I had at the time.

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

Who makes the Prop??? What is the prop number? Thanks Nutinbitin

I think you need to go with the same prop I got. 3 blade, 14x15p. I just checked, they are out of the 14" diameter.

 

[glastron50gl]

Re: Best Prop Size For Johnson 140 4-Stroke

Thanks. I think I will give it a try. Nutinbitin

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

Well I messed up that nice new prop last weekend, first time in many years. Anyway, bought a stainless prop that was 14 7/8 15p, I had an aluminum 14x 15p. Installed the prop last night and was not very happy at all. I was hitting 6200 rpm wot with the last one, was only getting about 5500 out of the stainless, why? Because it's heavier? I'm gonna try to return it and get the aluminum prop again. Any ideas why the rpm was lower?

 

[Sixmark]

Re: Best Prop Size For Johnson 140 4-Stroke

Well I messed up that nice new prop last weekend, first time in many years. Anyway, bought a stainless prop that was 14 7/8 15p, I had an aluminum 14x 15p. Installed the prop last night and was not very happy at all. I was hitting 6200 rpm wot with the last one, was only getting about 5500 out of the stainless, why? Because it's heavier? I'm gonna try to return it and get the aluminum prop again. Any ideas why the rpm was lower?

You installed a prop that was almost an inch bigger in overall diameter which will change things quite a bit

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

Sorry, my mistake, the stainless was 13 7/8. Was no diff. against my origional aluminum 14x17p

 

[Sixmark]

Re: Best Prop Size For Johnson 140 4-Stroke

Ok there seems to be a lot of prop questions regarding size and pitch and what to use on a particular boat, so here is a link to a good tool I have found for a starting point:

http://turningpointpropellers.com/

Just go there and put in your info such as engine size, boat size, approximate load, etc. and it will give you a good idea of what you should have on your boat

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

Man, I have been there and they are not right for all boats out there. My simple ? was why the stainless would not perform as good as the aluminum. The best prop for my boat is a 14x15p aluminum prop. Which I bought off this site a few weeks back and it worked like a charm till it got ruined. I thought the stainless would be a little better performance wise since they don't flex like the aluminum. I'm guessing the weight is why I could not reach 6200 rpm wot.

 

[Sixmark]

Re: Best Prop Size For Johnson 140 4-Stroke

Man, I have been there and they are not right for all boats out there. My simple ? was why the stainless would not perform as good as the aluminum. The best prop for my boat is a 14x15p aluminum prop. Which I bought off this site a few weeks back and it worked like a charm till it got ruined. I thought the stainless would be a little better performance wise since they don't flex like the aluminum. I'm guessing the weight is why I could not reach 6200 rpm wot.

Taking that into account, you may have just answered your own question.....usually when you go from alum to SS it requires a small tweak in size, Basically because the alum doesn't stay "true" whereas the SS does because it doesn't flex. So in a realtime scenario where the alum is distorting the SS is holding it's original shape thus changing the performance envelope just a bit.

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

I guess it's possible, but I lost everything, super hole shot, mid and top end power and speed. It is only a 140 hp, feels like a 90 with it om there.