Guests - If You want access to member only forums on HSO. You will gain access only when you sign-in or Sign-Up on HotSpotOutdoors.

It's easy - LOOK UPPER right menu.

Sign in to follow this  
Followers 0
Deep_Sinker

Props for 115 Yamaha 4-stroke?

14 posts in this topic

I'm looking for suggestions on prop choice for my Yamaha. I wasn't impressed with the over-revving of the stock 17 pitch aluminum prop, so I bought a 19 pitch stainless. The 19 lowered my RPMs by 1100 at WOT but didn't notice any speed gains and have a much slower hole shot. I am hoping to find a prop that doesn't rev out and would still be able to pop a skier out the water. Does such a prop exist? Any other suggestions?

Share this post


Link to post
Share on other sites

Maybe a 17P 4-blade?

What RPM's were you getting at WOT with these two props?

Share this post


Link to post
Share on other sites

What RPM's were you getting at WOT with these two props?

The information LMITOUT asks for above is information that's needed prior to any propping questions can be answered. Also, the RPM at WOT should be when you've got the boat running trimmed up to the optimum running position.

marine_man

Share this post


Link to post
Share on other sites

It's a tough motor to find the right stainless for. I tried several and gave up, went to the standard Yamaha 19P aluminum.

Northlander has this motor and he has a couple SS props he swaps out pending on what he's looking for.

Try Soderblooms and see what they have in mind for your specific hull.

Share this post


Link to post
Share on other sites

Maybe a 17P 4-blade?

What RPM's were you getting at WOT with these two props?

17P Alum hit the rev limiter at 6000

19P SS gets 4900 at WOT

Both get similar top end (39mph gps).

The SS was bought from Jay. He thought SS would lower RPM to 5600 and increase top end...

Boat is a 1700 Fisherman.

Share this post


Link to post
Share on other sites

I'd work with Jay and look at a 17P steel, that was what got me closest to the combo of speed and hole shot with decent RPMs.

Another option is the 19P alum, it works for me on almost the same lund hull.

Share this post


Link to post
Share on other sites

I was thinking raising the motor might help, but then again that will probably mess with your hole-shot. I'd try a 17P 4-blade. That'll get you hole shot and probably less RPM's. That motor should run between 5-6000 RPM's when lightly loaded and right in the middle would probably be ideal.

Share this post


Link to post
Share on other sites

17P Alum hit the rev limiter at 6000

Top end on RPM for that motor is 6k... were you going past, or are your sure you were hitting the rev limiter?

Your best best is to go with a 17 stainless 3 blade or the 4 blade as LMITOUT said.

marine_man

Share this post


Link to post
Share on other sites

Your best best is to go with a 17 stainless 3 blade

I agree. Not surprised your rpms and holeshot dropped so much going from 17 alum to 19 stainless --- you're bringing a lot of variables into play there. A 17 stainless or a 19 alum are probably going to give you better performance than the 19 stainless.

Share this post


Link to post
Share on other sites

Deep sinker send me a e-mail and you can come try some of my props out. I have a stainless that Jay cupped, holes and tweeked up a bit and I get 45 with a light load and hole shot and cornering is great. Average with full load and 2 guys is 40mph. Ill be around all weekend and we can test them out if ya like.

Share this post


Link to post
Share on other sites

Top end on RPM for that motor is 6k... were you going past, or are your sure you were hitting the rev limiter?

marine_man

6k is the rev limit. Motor would run up to and cut out.

Northlander, you have mail.

Share this post


Link to post
Share on other sites

6K is the top of the RPM spec.. I wonder if there's some variance in your Tach and you were running beyond 6k even though the tach didn't show it.

You should be able to run right up to (but not much over) 6k.

marine_man

Share this post


Link to post
Share on other sites

I have a similar set up as you deep sinker. 1800 fisherman with Johnson 2 stroke 115. It came with a 17 p 14 dia prop and @ WOT it was 5700 rmp. I did not have a spare so I replaced it with a 17 p 13 1/4 dia hustler aluminum and that gave a WOT @ 5400. I though with a smaller diameter prop I would gain rpm's but this one must be cupped differently. Now I get 39 mph (gps) and a hole shot that should have no prob popping a skier up.

Hope this helps. I know you have a 4 stroke so we may be talking apples and oranges?

Share this post


Link to post
Share on other sites

The gear ratio is most likely different too.

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  
Followers 0



  • Posts

    • If this crazy weather keeps up a guy might have to go to the mountains to have enough snow to ride.
    • I purchased a 20v 986 Dewalt brushless and used it with my Nils 8" and could not believe how fast it cut. Very close to my Tanaka motor as far as speed. My plan is to use it with my 6" Nils but wanted to give it a good test and it passed with flying colors. 
    • Pretty sure Bernie had that figured out. After the primaries I voted for "not Trump" You guys haven't picked up that liberals are still going for not Trump, even if that means Mike Pence (who from a political position standpoint is worse for liberals).   Instead you have Trump, a man incapable of taking any form of criticism regardless of how irrelevant it is to anything. Why do I post the crowd sizes? Because Trump, in a speech given only to members of the CIA, thought it was important enough to mention, as well as to have a team of his own people there to applaud when he mentioned the size of the crowds.
    • Here's the exact reason why I encourage everyone to buy the digital readout.  After getting holes drilled and everything setup, I always run my bathroom roof fan/vent to get rid of the moisture as the slush on the floor gets melted.  Yesterday I cranked the fan on max which moves some serious air, but I forgot to crack a window, which caused it to actually suction the CO from my water heater back into the house through a propane line pass through.  I looked up and saw 30ppm on the CO detector, which isn't high, but an indicator that something wasn't right.  All it took was cracking a window and turning down the fan for a minute and it was back to 0.  
    • You do realize the person you wanted to be president couldn't even understand the proper protocol for setting up a cabinet level email account don't you?    
    • I looked into fiberglass a few years back for a build.  I decided against it as it needed a wood backer.  Not sure if there is a different product out there now.  
    • finally got out Friday, put on 75 miles in the heavy drizzle, not the first time I have riden in the rain. the trails were OK, I rode in aitkin co. that doubles the miles I put on in the last two years.
    • they load tested the battery and said it was bad, everything else they said was fine, they put in a new battery. tried it today after sitting since Tuesday, and it started up fine, problem fixed.   I have a 2002 grizz carbed, and that sat for close to 3 months, went to start it this weekend, and it cranked for at least a minute (very cold blooded machine) and it started, it has the same battery that's in the Polaris.
    • Precious snowflake Trump needs a safe space from the media apparently.   I suggest you familiarize yourself with the word kakistocracy, because that appears to be the road we will be traveling down.
    • No,I am saying those who are left with jobs are working for those who Obama is happy to give money to for nothing. He was as bad as it gets in terms of getting people back to work after a recession especially when you factor in the amount of money he spent to do it.
  • Our Sponsors