prop for yamaha 90 4 stroke on 22 cruiser

Prop the boat for correct wide open throttle RPMs [@6000] with your anticipated load. Most of the time it will be a 15 pitch if you carry a typical C Brat load on a 22 .
Marc
 
I have a 2005 90 hp EFI Yamaha on my 22, which is pretty heavily loaded.

The dealer started me out with a 17" pitch prop, and, while it performs OK, the WOT rpm is limited to about 5200, so the prop is really too steep in pitch, and lugs the engine at the upper throttle settings and WOT.

The 15 is better, and will get one up to somewhere in the middle of the 5000-6000 recommended max rpm range, depending on the load in the boat, etc.

The 15 inch prop seems best for most of the ~2:1 gear ratio motors of 90 hp range. (The 2.59:1 Suzuki 90, on the other hand, works best with a higher pitched 17-19" prop, usually with a slight increase in diameter.)

A 15" Solas 4-blade prop has some advantages over a typical 3-blade 15.

While it will lose 1-2 mph at WOT due to the increased friction of the extra blade, it will handle heavier loads better, have a better hole shot, and vibrate less, particularly at low rpm near idle, when you can feel the vibration of the individual blades turning.

Some folks with really heavily loaded 22's have tried 13" pitch props, but usually concluded the 13 is too low a pitch (over-revs), and they would like a 14" prop instead as a middle ground solution to the 15/13, high/low, problem, but such a prop is very hard to find. (I do think someone came up with one recently, but will have to let them fill us in.) Otherwise, a 15 or 13 can be re-pitched by a prop shop, but that's more additional cost.

Stainless steel props are slightly more efficient, producing better top speeds and mileage, due to smoother surfaces and less blade flexing. They also will survive impacts that knock blades off aluminum and composition props, which is a real advantage in remote areas where it may be hard for you to go ashore and change a damaged prop with a spare. They do, of course, cost a lot more, usually 3 to 4 times as much.

I personally don't like the louder "clunk" encountered when shifting gears with the 12-14 lb stainless prop as compared with a 3-4 lb aluminum one, but that's probably a personal choice, as I doubt it affects the life of the shift dogs (clutch), or it would be a commonly discussed issue, which it isn't.

The composition props and more about these and other issues can be researched here by looking up the Propellers Forum articles.

Ultimately, the prop you choose should be determined by your own boat loading, driving, cruising, and perhaps fishing habits, as well as your experience with your boat, and the sea conditions you boat in.

The best place to start is with a standard 15" 3-blade aluminum prop, and see how you like it over a reasonable period of time, then, if you're really dissatisfied, make a change in the appropriate direction.

Hope this helps!

Good Luck!
 
Sam & Susie,

I just repowered with a 2008 Yamaha 90 (which I'm delighted with). I have a '94 Cruiser typically outfitted (not real heavy, but not bare bones). I'm starting with a 13.5 x 15 aluminum prop. So far so good. The engine is not broken in yet (I've got about 8 hours) but so far I find that the 13.5 x 15 gives me adequate power out of the hole, nice top end speed (about 25 kts on flat water) -- and a comfortable cruise speed of 13-23 kts (15-25 mph). WOT is 5700, but I think that will come up as I haven't been able to really open her up on flat water yet -- too soon.

Here are some previous threads that you may find useful:

Prop Suggestions for Yamaha 90?
http://www.c-brats.com/viewtopic.php?t= ... sc&start=0

Sustainable Max RPM
http://www.c-brats.com/viewtopic.php?p= ... ht=#122936

Breaking in new motor -- and prop suggestions
http://www.c-brats.com/viewtopic.php?p= ... ht=#123566

Cheers!

Matt
 
I can also attest to the 13.5 X 15 though the Jenny B had the F75 Yamaha. Same results. Same engine,but the 90 is tuned for better high end HP. Also started with the 13.5 X 17 but immediately dropped down to the 15 pitch. It did a great job. Flat out with full fuel tanks and not much more than me, I'd see 30-32 mph @ 5600 rpm.

Don
 
Here's the report/ update on the new motor/ propeller performance. Tortuga is a '94 22 Cruiser, loaded with to a midrange weight (not sparse, but no cruising equipment on board beyond the dink). One person, 18 gallons of gas. 10 gallons water.

The engine is a 2008 Yamaha EFI 90 with eleven hours. The propeller is a Yamaha 13.5x15 aluminum.

Location, West Anacapa Island -- Ventura CA. Sea conditions: 1-3' wind waves, 2-3' swell at 9 seconds.

First, I noted that I could actually trim the boat with the new motor. With bow down full due to the chop, I was getting the following numbers:

4500 RPM -- 24 mph*
5000 RPM -- 25-26 mph**
5500 RPM -- 26 mph**
5700 RPM -- 29 mph**
5800 RPM -- 30 mph**
WOT -- 5800 RPM

* Surprisingly comfortable;
** In general this was not comfortable, but with the bow down there was little slamming.

Later, when the water flattened out more:

4500 RPM -- 26 mph
4700 RPM -- 27 mph
4900 RPM -- 28 mph
5000 RPM -- 28-30 mph
5100 RPM -- 29-31 mph
5500 RPM -- 31-33 mph
WOT -- 5800 RPM

In flat water there was no slamming, but the boat did become squirelly at around 30 mph. With the swell (which we were chasing) the boat wanted to round up a bit when the chines sunk in.

In summary, I would recommend the 13.5x15 aluminum prop to anyone running a Yamaha 90 on a midweight 22. In flat water I would expect comfortable cruising at 15-25 mph (4000-4500 RPM), in choppy conditions I would expect comfortable cruising at 12-15 mph (3000-4000 RPM).

I don't know how she'll run with 4 adults plus scuba/fishing gear, but I rarely bring that kind of weight along. I'll post numbers when that happens.

Cheers!

Matt
 
Great report and numbers. You migh consider picking up a back up prop in 13" pitch--may be better for heavy loads, and if you go to higher elevations, such as Lake Powell, will be a better prop up there.
 
I have broken my 17 pitch 3 blade prop and gone to my spare 15 pitch 3 blade on a 07 Yamaha 90 4str. I guess I must be considered lightly loaded. I have the following experience:
15 pitch alum 4700-4900 rpm 20 mph heavy gas usage (cruise) 9 gph
17 pitch alum 4400-4600 rpm 20 mph moderate fuel usage (cruise) 5 gph

Any one else have similar experience? at sea level.

Just ordered a new 17 pitch BS pro Prop.

Thanks
 
Should also mention the 15 pitch results had 3 adults, 2 children, a dog and a dinghy. The 17 pitch results 2 adults and fishing gear (typical use).
 
A Fishin C":1o3zou09 said:
I have broken my 17 pitch 3 blade prop and gone to my spare 15 pitch 3 blade on a 07 Yamaha 90 4str. I guess I must be considered lightly loaded. I have the following experience:
15 pitch alum 4700-4900 rpm 20 mph heavy gas usage (cruise) 9 gph
17 pitch alum 4400-4600 rpm 20 mph moderate fuel usage (cruise) 5 gph

Any one else have similar experience? at sea level.

Just ordered a new 17 pitch BS pro Prop.

Thanks
Click to expand...

A Fishin C-

I can understand SOME difference in gph consumption due to a change of 2" in prop pitch, but a change from 5 gph to 9 gph would make me rethink how I arrived at the gph numbers.

Do you have a fuel consumption rate / flow meter?

Any change the calculations or fill up numbers were off?

A 17" vs a 15" prop is a 1.133> ratio, while
a 9 gph to 5 gph is a 1.8 ratio.

Either (for that motor) the 17's a magic prop, or the 15 a dead end, or ??? :D

Joe. :teeth :thup (With all due respect!)
 
Joe, see my comments on loading. Maybe that in combination with tides...
Not using a flow meter just looking at the tanks.

Just out of curiosity are your experiences with props at sea level? or at a higher elevation?
 
A Fishin C":q5muihlt said:
Joe, see my comments on loading. Maybe that in combination with tides...
Not using a flow meter just looking at the tanks.

Just out of curiosity are your experiences with props at sea level? or at a higher elevation?
Click to expand...

A Fishin C-

Yes, the loading, tides, and estimations could account for a lot of difference!

Most of my experiences are at sea level in the ocean or California Delta, or at 1000 ft or so in the Sierra foothills. We also fish Eagle Lake (5200') and Lake Almanor (4200') quite a bit.

I don't mean to be disrespectful, it's just my sense that the 2" difference in props doesn't equate to the difference in ghp, without other factors involved.

Joe. :teeth :thup
 
In thinking about last season's Lake Powell trip, I took my spare 13 1/4 x 17 aluminum prop to the prop guy in town. Running Lake Powell with a Yamaha 90. 4 stroke efi and moderately loaded I saw 5100 rpm at wot. I could stay with Chris on Rana Verde but not much left. I'm having the prop repitched to 13 1/4 x 15. I'll be leaving a lot of stuff at home this season so will be lighter. Should give me closer to the better end of the rpm range wide open. Not that I'll run there all the time but should be better for the engine. If the waters flat it can be fun to rip along for a bit. George
 
Jacobsen is finishing install on a 2014 Yamaha 90 on my boat right now. I just realized I have not offered them any input as to what prop to start me out with. Any current information as to what might be good? Most of the time I am 2-3 guys and a decent amount of gear for fishing and cruising

1981 22 classic

It looks like a safe bet to start would be a 13.5" x 15 prop?

Any input would be much appreciated
 
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