Michigan 011003 prop specs?

[superbenk]

My boat (1980 Century 190 w/ OMC 140/400 Stringer) has a 3-blade Michigan aluminum prop with '0110Q3' stamped in the hub, but I can't find any specs about what it is. Anyone have any ideas?

 

[superbenk]

Re: Michigan 011003 prop specs?

Ok, I'm an idiot. That's not a 'Q', it's another '0' (zero) with a nick in it :redface:

Anyhow, I found the prop here on iBoats:

http://boatpropellers.iboats.com/Michigan_Wheel-Michigan_Match_Aluminum-Propellers/011003/

I'm looking at it since I'm hitting close to 5000 RPM with the throttle all the way down & I'm thinking that's too high for my motor. At 5000 RPM I get roughly 35 MPH & I'm wondering if I could either keep that speed while lowering the RPM to something like 4600 RPM or maybe even gain a MPH or 2 with a higher pitch prop?

This 011003 prop is a 13.25" x 17" pitch - should I look at a 19" pitch?

 

[bigrockets]

Re: Michigan 011003 prop specs?

I'll show how much I've learned on this forum in just a few days. You should post additional information as follows. What are the WOT specs for your engine. What do you use the boat for (fishing, cruising, watersports)? Number of passengers and extra weight. If you lower the engine speed by going up in pitch outside the manufacturers recomendation you cause stress to the engine by lugging it. It seems to me you are in the right ballpark but we don't know your engine specifications for WOT operation. As I have learned there are a lot of variables and each prop is a compromise between top speed, engine operating range and the ability to pull from a standing start. I now have two props, one for a loaded boat pulling tubes and one for light loads dashing to the favorite fishing spot with two people. You might also try one of the prop selection calculators that will give you more insight.

 

[superbenk]

Re: Michigan 011003 prop specs?

Well, to be fair, I said I was aiming for 4600 RPM. I think that's my spec'd WOT. Unfortunately I don't have the WOT specs for my drive.

I'm hitting ~5000 RPM according to my dash tach. I want to verify that with my shop tach, but haven't yet. This is with a light boat (just me), so I need to test with the family in the boat. Regardless, I'm looking for a tad bit more speed and/or (more importantly) bringing down that high RPM slightly. At this point I just run at 3/4 throttle and that's fine, but I'm exploring options. There's a 19p prop for my boat here on iBoats for $85 that might fit the bill. We don't waterski, but we do tube some (slow for the kids) so I'm not super worried about low-end torque & more interested in RPM & speed. Having a spare prop seems like a decent idea too.

 

[usskydvr]

Re: Michigan 011003 prop specs?

You are correct, 5000 RPM is too high for your motor (4400-4800). Get the 19 pitch prop. That should put you right at 4600-4700.