wot only 3200 rpm

[peedee]

I have a 50HP yamaha 2 stroke with a 11 5/8 X 11G prop on a 20 foot pontoon. I only get 3200 rpm. On the yamaha website in the performance bulletin on a similar boat has a prop of 12-1/4 x 9. Is the difference in the props that different that I would get that much closer to 5500 at WOT, or is there something else not working correctly.

[MPosey519]

*Beating the dead horse* Carbs?

[peedee]

my brother in law took the cards apart this spring and cleaned them all out. We did have an issue with the emergency enrichment valve. We have to leave it open or it stalls out. So you think the carbs are still clogged? It rides around fine, just can't get the rps up and it is slow anyway with a 50HP on it.

[MPosey519]

That's the symptoms mine had before I rebuilt the carbs. Not saying that's it, just what I got

[evinrude2stroke]

3200 rpm's doesn't sound right. Sounds like a prop issue. I have a 40hp and I get 4500 rpm wot. gets me up to 18 mph which about max for my boat. I'm not exactly sure about them but there is kind of a science to them. Try the search function, there are a lot of threads on prop sizing on here.

[shoundog]

peedee, I can only tell you that I saw a big diff in changing my prop. See my post about the 200 rpm rule.
Doug