Setting the pitch on Maxprop

[drchpete]

My maxprop is set a B/Y and V/X. I am only able to get to 2700 or so RPM if I am to keep the temp in the normal range. If I push it up tp 2900 or certainly 3000 the temp rises. Cooing sytem has been cleaned so it's not the problem. I read somewhere (can't find it again) that someone had the same problem and dialed back one notch on the maxprop and problem was solved wihtout loss of speed, just higher RPM (3000). I'd be fine with 2700 cruise but would feel better if I knew I could push it harder for a while if needed. No reserve RPM like I am now. Anyone have any recall or info on this? Also considering the autoprop to replace this maxprop if anyone has any comment.

Thanks,

Chris

 

[Steve Dion]

Chris:

I don't know the specs on your engine, but typically you want the engine to be able to operate a the Max RPM while underway (assuming clean bottom, nothing to impede the exhaust flow, mixing elbow etc).

You may want to contact the mfg and see if they have the specs for your particular setup. With a traditional fixed prop you normally get about 250-300 rpm +/- additional for each degree of pitch.

I am also considering a new prop. Can you tell me why you decided on a Max Prop?

 

[Rick486]

My maxprop is set a B/Y and V/X. I am only able to get to 2700 or so RPM if I am to keep the temp in the normal range. If I push it up tp 2900 or certainly 3000 the temp rises. Cooing sytem has been cleaned so it's not the problem. I read somewhere (can't find it again) that someone had the same problem and dialed back one notch on the maxprop and problem was solved wihtout loss of speed, just higher RPM (3000). I'd be fine with 2700 cruise but would feel better if I knew I could push it harder for a while if needed. No reserve RPM like I am now. Anyone have any recall or info on this? Also considering the autoprop to replace this maxprop if anyone has any comment.

Thanks,

Chris

Best advice on Max Prop is to call Kevin Woody at PYI and discuss with him. He is very knowledgeable and willing to help. They have lots of data and experience with Yanmar engines.

 

[drchpete]

Steve, the Maxprop was already on the boat when I bought it (2nd owner). I switched my old Catalina 34 from fixed 2 blade to the Autoprop and wow, what power. My engine temp did creep up a few degrees on that boat but stayed in the normal range. My speed increased by almost 1 knot, and bogged down less in a head sea. If I didn't have this prop on the boat I'd get the Auto prop but since this one is already on I'm a little less apt to spend the $ on the Autoprop. Still considering it though.

Rick, thanks for the name. I have the prop off now and am sending it back to the factory for maintenance (surveyor recommended it due to a little too much play in the blades). It's a complicated thing this prop...a whole bunch of pieces and parts!

 

[Steve Dion]

Thank you for the feed back. I am evaluating different props and all of them seem to have their own set of issues.

 

[Kordie]

I was given a max prop with my boat. The owner told he he didn't like it when going astern.

I am guessing maybe he didn't have the pitch set right. I plan on getting it refitted on my next haul out, perhaps I need to find an authority on it.

Interesting read folks.

 

[Bowedtoothdoc]

I was given a max prop with my boat. The owner told he he didn't like it when going astern.

I am guessing maybe he didn't have the pitch set right. I plan on getting it refitted on my next haul out, perhaps I need to find an authority on it.

Interesting read folks.

There must have been something wrong with that prop... I have a max prop on my boat and it backs up beautifully. In fact a properly working max prop should back better than almost any prop including a standard prop. When shifting into reverse the prop rotates around and gives you a similar pitch to being in forward. However, I am having a similar issue to the OP in that at WOT I am only hitting 3100 rpm instead of the Yanmar rated 3600. I am starting to think that the issue is not with the prop but something with fuel or exhaust.

 

[drchpete]

I agree with Bowtooth that the Maxprop does back very well. Mine definitely has prop walk to to port until I get up some sternway, but that prop walk can also be used to my advantage. I will say that the Autoprop I had on my Catalina 34 was 2nd to none though and that includes backing. The power in forward was unmatched by any fixed blade as well. My problem here is not with WOT (actually have not tested that) it's with overheating beyond 2700 RPM and suspect the setting of the prop.

 

[drchpete]

Maxprop Correct pitch

Just spoke with Jerome at PYI. After evaluating my Maxprop 3-blade and looking into the correct settings, he concluded that the pitch was indeed set too high at 26 degrees...should be 24 degrees. He also said that it well could be the reason for my 466 with 4jh3te overheating above 27-2800 RPM. Will find out certainly in a month or 2 when she launches and will post the results

 

[artboas]

Re: Maxprop Correct pitch

I had a 3 blade max on my 40.5. It was excellent, and had zero prop walk on reverse. I was able to stop the boat in 1 boat length from full speed. I did tweek the settings 2 or 3 times to get it perfect.
On my 49 I have a 4 blade variprop. Serious piece of equipment . I went 4 blade as the boat is pretty heavy. Easilly gets 8 knots into head seas.
Zero prop Walk
Quite pricey, but necessary.

 

[Bowedtoothdoc]

Today I adjusted my prop down from 24 degrees to 22. I am launching tomorrow and will report back how much of an RPM increase this provides. It should put me right around 3600 @ WOT.

 

[drchpete]

Today I adjusted my prop down from 24 degrees to 22. I am launching tomorrow and will report back how much of an RPM increase this provides. It should put me right around 3600 @ WOT.

Thanks in advance for getting that info back to us. I'd rally like to know how that works out. Did you get any overheating at your current setting if you throttled up to 80% of max RPM?

 

[Bowedtoothdoc]

Thanks in advance for getting that info back to us. I'd rally like to know how that works out. Did you get any overheating at your current setting if you throttled up to 80% of max RPM?

I never had an overheating issue, just low rpms @ WOT. The boat was splashed yesterday and my adjustment appears to have solved the problem. On my run over to the marina she made between 3600 and 3700 rpm @ WOT. Not sure what speeds I was getting as the electronics were not yet hooked back up from the decommissioning.