Overproped=Overheating

[jpv]

A short while ago I posted about my Hunter 37' with Yanmar 3QM30 running hot/overheating,, 3200rpm unloaded and 2200rpm loaded ! What is the correct dia/pitch for a 3 blade unit for the boat ?? I need to get this in gear RPM about 2850-2900 RPM ,, Tell me what you think the pitch/dia should be !! thanks joe

[never monday]

Joe,
Get with a reputable prop shop in your area. They will be able to do any fine tuning for you if necessary. Your engine needs to achieve 3200 RPM underway.

[SkiprJohn]

Aloha jpv,
I don't know if our search engine is working properly but we've covered this subject in several different threads. You might try searching for "proper prop size."
The right diameter and pitch are dependent on your prop shaft speed so hp and transmission ratio have a lot to do with it.
What diameter and pitch do you have now?
Kind Regards,
JohnL

[SkiprJohn]

http://www.cruisersforum.com/forums/...size-5972.html

Try this.

JohnL

[jpv]

I've sent the prop of to Admiral /C&B prop service in Tampa and Am waiting for a call back with their recomendation and I'll post the talk. joe

[jscott]

If I remeber correctly 1 inch less pitch increases the RPM by 10%.

You should run the biggest diameter you can for low speed thrust.

[never monday]

Originally Posted by jpv

I've sent the prop of to Admiral /C&B prop service in Tampa and Am waiting for a call back with their recomendation and I'll post the talk. joe

Their one of the better prop shops around W.FL