Can I run my old Yam 50 above it's max RPM?

Pat · 10-10-2009, 01:46 PM

I have a yamaha 50 (1985) on the back of a Fletcher 13' boat. The manual says that acceptable top revs are between 4500 - 5500. Stupid question I know, but can I run it above this without changing parts? It's not really doing it's job, will NOT go up on the plane with 4 people on it (and the boat is rated for 40hp!), I don't have a tacho at the minute but suspect it might be running low. I presume there isn't a rev limiter?
Sorry if it's a daft question, I'm more used to chainsaw engines where you can run them right up, than old outboards. Need more power!

Pat · 10-10-2009, 01:52 PM

Oh, and more money.

Does anyone rate the Nauticus trim tabs at all? The boat feels like if it could just get up on the plane 4-up, it would sit there happily, but at the minute it just digs through the water like a gin palace.

daren · 10-10-2009, 02:20 PM

What is your idea of "4 up"?

My old 14' Fletcher with 55hp Yam used to get on the plane 4 up no problem so maybe yours in down on power, wrong prop or more likely 40hp just aint enough. Changing your prop will change your rev's but I dont think it is ever going to get you what you want and you'll shorten the life of the engine.

Put the right prop on for that engine at the recomended rev's and only have 2 adults in the boat - that is the answer but not the one your looking for.

Why not buy a nice Phantom 25 and have 5up with no worries about getting on the plane.

Pat · 13-10-2009, 09:14 AM

Oh, I'd love to - but suffer from skinny wallet syndrome! Don't think a 25" would like being launched where I launch my boat from, either - not much traction to pull it out!

hunton69 · 13-10-2009, 12:41 PM

My first boat was a 13'6" concord with a 50hp the only way that got on the plane 4 up was by all leaning forward.

Pat · 13-10-2009, 02:50 PM

Quote:

Originally Posted by daren

What is your idea of "4 up"?

My old 14' Fletcher with 55hp Yam used to get on the plane 4 up no problem so maybe yours in down on power, wrong prop or more likely 40hp just aint enough. Changing your prop will change your rev's but I dont think it is ever going to get you what you want and you'll shorten the life of the engine.

Put the right prop on for that engine at the recomended rev's and only have 2 adults in the boat - that is the answer but not the one your looking for.

Why not buy a nice Phantom 25 and have 5up with no worries about getting on the plane.

Not 4 chubbies, just four normal sized adults, 2 blokes 2 girls, maybe a small bag and 20l of spare petrol. The rear seats in it are rear facing as well, so that must help with weight distribution a bit? Still no getting up on the plane though.
I need to get my prop repaired and try it with a tach connected!
Prop is 11 1/4 x 14 as I remember, but I gave it a battering against a rock last time out and haven't had a chance to get it welded up yet...

Pat · 13-10-2009, 02:51 PM

Quote:

Originally Posted by daren

What is your idea of "4 up"?

My old 14' Fletcher with 55hp Yam used to get on the plane 4 up no problem so maybe yours in down on power, wrong prop or more likely 40hp just aint enough. Changing your prop will change your rev's but I dont think it is ever going to get you what you want and you'll shorten the life of the engine.

It's running a 50 - a 40 is what the hull is rated for!