Prop question - midrange yamaha 60hp

[mitserv]

Hey there everyone. I've been lurking for a while and decided to go ahead and post this. I was really hoping to get a few opinions about something that has bugged me since I bought my boat a couple months ago. I purchased a 2001 G3 Pro175 with a 1999 60hp Yamaha. The original alum prop was all banged up so I went ahead and purchased a replacement in (almost) the same size and pitch (13 1/2 X 15) but in a stainless. I installed the new prop before I ran the boat for the 1st time. The new prop is a Michigan Wheel Apollo model 13 3/4 X 15. I recently took the boat out for the first time and discovered my RPMs were easily able to hit 7000 if I were to push to WOT--obviously WAY too high. Recommended was 5000-6000. My cruising speed at the recommended 6000 RPM's was about 32mph and I was quite sure I had purchased the wrong prop. I checked online everywhere I could find (including here!) and cannot seem to find anyone who has ever had a similar boat/motor and asking about prop size. Now according to every prop size calculator I can find online, I should be running a 19p or 21p however the prop store I talked with said that this yamaha 60 would never turn that prop and I would never get on plane. My main concern is engine life but it would be nice to be able to get up around 40mph if it's possible in this boat. Okay, does anyone have any suggestions for me as I don't want to purchase ANOTHER prop that is the wrong size!
Thanks in advance to anyone who may be able to help.

[zooker]

A 13 3/4" by 15p toppin out on a 60??

Better check your tach. Stock yamahas have a 6150rpm rev limiter it will hit it and rev down. -sounds like a mis fire-..on my 50 i run a 10.685x14ish stainless. around 5800rpm.. I don't see how you can turn a 13.75x15p at 7000 on a 60 horse. That wheel is just too big most 50-70 horse yammers run 10.5 thru 12 inch wheels.

A 13.5 is a small hub 90 horse prop...

zooker

[mitserv]

Thank you very much for the info Zooker, I'll have to get the tach looked at next weekend to see if that is my problem I suppose

[1FASTLASER]

Zooker is dead on Accurate.......13 1/2 is for V4 engines not inline engines...Get I still cant figure out why you are hitting 7 on the tack. Double check that prop size again and as zook stated get your tack checked at a local boat shop. Something is amiss.

[Culln5]

Something doesn't sound right. My 130 is spinning a 23P at 5900 RPMS.

[Bub]

Originally Posted by 1FASTLASER

Zooker is dead on Accurate.......13 1/2 is for V4 engines not inline engines...Get I still cant figure out why you are hitting 7 on the tack. Double check that prop size again and as zook stated get your tack checked at a local boat shop. Something is amiss.

I've made arrangements to take the boat in for service to have everything checked out. I'll be sure to let ya'll know what the results were. I'm actually hoping that it is my tach and that I don't have any other issues. What you're sayin' makes total sense because if the limiter never kicked in, there is no way I could actually be reaching 7k, right?

[zooker]

Not use less they have been into the computer. This typically is not a good sign on a mid power motor.

zooker

[Bub]

I really don't think the previous owner would have had an interest in disabling the rev limiter (I didn't even realize that was possible). He and his wife used the boat for cat fishing at their local lake (very small lake) on weekends during the summer...they rarely even used the big motor. I guess it's possible though that something is wrong which is preventing the limiter from kicking in, I'll find out when I get it serviced next week. I'm glad I posted the question here in this forum though because I was on my way to purchasing a new 19" prop instead of checking out to see if I might have something wrong with the motor. You guys may have saved me not only money on a new prop ($400) but also a possible major engine repair sometime down the road (!!$$$!!). Thanks!

[1FASTLASER]

Bub I might have made a mistake. I went back and did some research on the Hammer props and it seems that everything I see listed is in the 13-13 1/2 " range as far as diameter is concerned. Now the 15p is definately wrong I will argue that point. I was running a 15 on a 40hp mariner that would scream. So did you get the tach checked out. Ifn ya did lets get down to the nitty gritty and get you to running correctly.

[Bub]

Mornin' 1fast, I ended up having to work all weekend this weekend but I'll be on the water from Wednesday-Sunday this week (KY lake!!). My father in law did use the boat this weekend tho' (filled the livewell on Friday) and said although the motor ran strong it still revs to 6k with more throttle to go... I am going to try to get the boat into service sometime this week to have the rev limiter and the check looked at to make sure both are working correctly. Till then, I'm going to just keep an eye on the rev's and just take it easy. I'm not making any long runs on Ky Lake anyway, I put in about 3 mi from where we will be fishing. I'll get back with you later this week though and we'll figure out what's going on and if need be, which prop may work the best. Thanks again for the effort!

[RichZ]

I run the same hull as you, but with a 50 Yamaha. I run 31MPH (on the GPS) at 5400 RPM with a 10 by 13 stainless 4 blade. I have a comprop the same size, and it actually runs a stitch faster than the stainless, at a hundred RPM less.

[Bub]

Originally Posted by RichZ

I run the same hull as you, but with a 50 Yamaha. I run 31MPH (on the GPS) at 5400 RPM with a 10 by 13 stainless 4 blade. I have a comprop the same size, and it actually runs a stitch faster than the stainless, at a hundred RPM less.

Thanks for the info Rich, I'm wondering what kind of difference I would see with a smaller diameter prop like perhaps a 11X17 or 10X19 etc...


I was able to get things looked at this past weekend and here's where I'm at...
30.2 mph GPS at 5800 rpm with my 13 5/8 X 15" SS Apollo prop. Of course, this is with 20 gal of gas, full livewell with almost 30 lbs of fish too, a lot of tackel and 2 people. I found out that my tach was bad which is why I originally thought I was under propped, but now it has been replaced and everything runs very well... but, I would be very open to any alternate setups that will make the boat faster without effecting the handling or the engine life. From what I've been reading though, this boat/motor combo really isn't made to go much faster.

Any thoughts?

[1FASTLASER]

I have a couple of things ya can do but first do you have a water pressure gauge???? To go any farther with performance you have to have a H20 gauge....... I am sure your probably dragging your leg.....{lower unit low in the water} but to effectively set this ya need a water pressure gauge.....then the next step would be to get your prop Balanced and blueprinted. Between the 2 you should get to the high 30's fairly easy.

[Bub]

I wish I did... This little boat doesn't have a water pressure gauge though. I checked how the motor is mounted and I am on the second hole from the top (I could lower the motor one hole or raise it two holes if that makes any sense). Anyway, I think I'll just leave it alone becuase the overall handling of the boat is just awesome. One thing is for sure, I have learned a LOT since I started reading the forums on this site and will now know more about what to look for in a boat. As I mentioned, this is the first boat I've owned and although I got a REALLY good deal, It's not exactly what I would select if I was going to do it again today. I think I'm just going to have to accept 30 - 35mph and just concentrate on catching fish! I'm going to hold on to this boat till this time next year, then upgrade to something a little bigger, better, and faster.