Yamaha f300xca

Squire, The Rev4 and the OFS4 are quite similar in performance. Unfortunately the Rev4 is about the only prop that Yamaha does not recommend for their outboard due to some prop shaft seal problems they've had with only that prop. Seems strange, I know but....
 
I heard(read?) that as well but there has also been some speculation that Yamaha used the incorrect prop shaft seals for a period and after 2012 they went back to the prior seal and the Rev4 problem went away (Ken Reeves). I'd love to try the Rev4 but the questionable history and the unlikely event of finding the kind of deal I did at the time has me looking for an alternative. I really don't need to improve on the SWS II but it is in my nature to tinker and I'm easy to convince that I need a spare anyway.
 
Ordered the Powertech OFS4 in 16P from Olympic Propeller so now it's just a waiting game. It's coming direct from Powertech; it seems with all the variations they are just too expensive to stock.
 
Got my prop today, does anyone know if the thrust washer for the Yamaha SWS II prop with SDS can be used with the OFS4?
Thanks, I get my boat back tomorrow so I cant even check for myself and patience isn't my best quality.
 
Thanks Old Fisher, I'll check it out for fit tonight. It may be a week or two before I get to try the OFS4 prop. I had the motor raised one hole and wedges installed to improve the performance of the SWS II and hopefully address the porpoising by adding more negative trim. I'll see what impact these changes had for comparison with the SWS II then I'll try the OFS4. I'm afraid changing too many things at once will just have me wondering what did what. I'll collect some data on both and post it here in the near future.
 
Unfortunately, there will be a bit of a delay before I post results of the OFS4 performance. Got out yesterday and found that the wedges probably did help the porpoising although I needed a bit of trim to level the boat with a full water tank. Even after raising the motor one hole the cavitation plate is still buried on plane at 30 mph. I won't address this until I see if the OFS4 provides the stern lift to correct it. I found my best cruise at 3400-3500 rpm at 25-27 mph and fuel burn of 7.9-8.1 gph which gave me just over 3 mpg. I got up to 5800 rpm at WOT trimmed up and 50 mph (no reason to note fuel burn) then when I backed off the Yamaha speedo stayed at 50 mph. I didn't feel any impact but it stopped working. The bright side is the fuel economy I get at 3500 rpm and 50 mph ;).

I couldn't get the depth to show up on the chart page then my sonar went completely haywire and stopped reading the bottom on the sonar page as well. My system is a new HDS 12 Carbon with a P79 in-hull transducer.:mad:

On the positive side, I drug a line for the first time with this boat and 15 minutes in I was hooked up with a nice Chinook. I didn't want to harm him though so I released him about 40' from the boat:D
 
Gazza said:
So does porpoise mean that it lists to one side at times? I currently have a 1995 campion and at times I struggle to get it to run straight and balanced.
Click to expand...

wet foam possibly
 
I got tired of my speedo getting clogged with debris and rigged up the GPS input to my command link gauges. Suggest you look at doing the same!
 
ryanb said:
I got tired of my speedo getting clogged with debris and rigged up the GPS input to my command link gauges. Suggest you look at doing the same!
Click to expand...

If I can do that with the 6YC Multifunction Meter that just might be an option, thanks.
 
I finally got out for a run with the OFS4 16P and I must say I'm underwhelmed. The SWS II 17P edged it out in every way except time to plane and maybe maneuvering around the docks. It will make a good spare but I'm putting the SWS II back on. I went from best cruise at 25-27 mph at 3400-3500 rpm and fuel burn of 7.9-8.1 gph which gave me just over 3 mpg with the SWS II to 24 mph at 3500 rpm, 9.1 gph and 2.6 mpg with the OFS4. I tried up and down from here to see if it had a better sweet spot but no such luck.
Top speed at WOT was down from 50 mph at 5800 rpm to 47 mph at 5900 rpm. I expected the drop here but hoped for better in the cruising range and fuel economy.

The bright side was that it wasn't enough of a problem to head back to the dock and we caught and released a couple of nice Chinook.
 
Squire, it seems that you might have liked your OFS4 better with another inch of pitch. My 17P gives me 29-30 mph at 3500 and 2.8-3.1 mpg. 4000 rpm gives me 34-35 mph and 2.6-2.8 mpg. WOT is 56-5700 and 49-50 mph. My WOT is lower in the rpm range than yours but I doubt that I'm overloading the motor. Hope not.
 
Old Fisher said:
Squire, it seems that you might have liked your OFS4 better with another inch of pitch. My 17P gives me 29-30 mph at 3500 and 2.8-3.1 mpg. 4000 rpm gives me 34-35 mph and 2.6-2.8 mpg. WOT is 56-5700 and 49-50 mph. My WOT is lower in the rpm range than yours but I doubt that I'm overloading the motor. Hope not.
Click to expand...

I won't argue with that statement Old Fisher. It seems my results are about what I would have expected going down one inch in pinch with the SWS II. I expected to gain on the mid-range because of my previous experience with the Rev4 going down one inch in pitch from an Enertia on a Merc 350 MAG I/O. I lost 1-2 mph top end and gained everywhere else.

I don't think you're overloading your motor at all; those are fantastic numbers! Now if I can just find someone who needs a barely used OFS4 16P ;)
 
Have had several 4.2l 300's all hit close to 1000hrs with zero problems. Regular servicing every hundred hours and make sure to change impellers at 200hrs and your golden.

I trade in so haven't run any over 1000hrs but I know a few guys pulling 3000 plus hours with no issues still going strong.
 
Old Fisher said:
Squire, it seems that you might have liked your OFS4 better with another inch of pitch. My 17P gives me 29-30 mph at 3500 and 2.8-3.1 mpg. 4000 rpm gives me 34-35 mph and 2.6-2.8 mpg. WOT is 56-5700 and 49-50 mph. My WOT is lower in the rpm range than yours but I doubt that I'm overloading the motor. Hope not.
Click to expand...

I exchanged the OFS4 16P for the 17P and tried it out today. I didn't get to really open it up due to choppy conditions but I was impressed with the cruise performance. I had the trim right down (with wedges) and some trim tab and still got 27 mph at 3500 rpm and 2.6-2.8 mpg. I would likely get the same numbers as you did above in calmer waters where I could trim up a bit and back off on the tabs. My numbers with the SWS II 17P were comparable but in much better conditions with less tab and higher trim. I really liked going down to 3200 rpm and staying on plane at 23 mph; I didn't fall off step until below 3000 rpm.
 
Squire said:
I exchanged the OFS4 16P for the 17P and tried it out today. I didn't get to really open it up due to choppy conditions but I was impressed with the cruise performance. I had the trim right down (with wedges) and some trim tab and still got 27 mph at 3500 rpm and 2.6-2.8 mpg. I would likely get the same numbers as you did above in calmer waters where I could trim up a bit and back off on the tabs. My numbers with the SWS II 17P were comparable but in much better conditions with less tab and higher trim. I really liked going down to 3200 rpm and staying on plane at 23 mph; I didn't fall off step until below 3000 rpm.
Click to expand...

Excellent. I love that prop and I think you will too when you get a chance to run it in better conditions.
 
Squire said:
I exchanged the OFS4 16P for the 17P and tried it out today. I didn't get to really open it up due to choppy conditions but I was impressed with the cruise performance. I had the trim right down (with wedges) and some trim tab and still got 27 mph at 3500 rpm and 2.6-2.8 mpg. I would likely get the same numbers as you did above in calmer waters where I could trim up a bit and back off on the tabs. My numbers with the SWS II 17P were comparable but in much better conditions with less tab and higher trim. I really liked going down to 3200 rpm and staying on plane at 23 mph; I didn't fall off step until below 3000 rpm.
Click to expand...

When you changed the 17P three blade to the 17P four blade, did you stay at the same prop diameter with the four blade? Or did you have to go down?
 
Barman said:
When you changed the 17P three blade to the 17P four blade, did you stay at the same prop diameter with the four blade? Or did you have to go down?
Click to expand...

They are almost the same diameter; the SWS II 3 blade is 15-1/2" and the OFS4 is 15-1/4". Conventional wisdom suggests that you would go down in diameter or in pitch for similar performance from a 3 blade to a 4 blade prop but there are other variables in play. These include blade shape, blade area, rake, cup etc... Conventional wisdom and prior experience is what made me go to the 16P first but it spun a little too easy for my liking. Although the mid-range numbers are almost identical now, I am slightly quicker to plane (the motor doesn't growl as much overcoming the prop) and I can stay on step at lower rpms. I have to wait for a better day to check out the upper range but it just feels smoother overall. In this case, with this boat and motor, the same pitch is better.

When I went from a 3 blade 18P Enertia(14-1/4") to a 4 blade 17P Rev4(14-5/8") on a prior boat the drop in pitch was the right choice. It is more art than science, but science can narrow it down for you.:D
 
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