1850ls / Rev4 19 pitch too big?

[Kevin23]

Originally Posted by zogman

I also run a 150 Yamaha on a 2014 1850LS. The 19 pitch Yamaha prop was not the answer. Right now I have a 17p Merc Vengence. The hole shot is great even when fully loaded however I top out at 5700 rpm which is 41 mph.
I will be trying the 17p Yamaha this next weekend.

With what I have now I can cruise at 33 mph which is 4600 rpm. I probably hold it there for about 10 miles at a time. Is that running it too hard???

On any motor, for long runs you should be in the optimum RPM range which I think for your motor is 5000-6000? 4800 isn't anything to worry about, heck your tac could be off by 200 easily. As for the length, 10 miles isn't going to hurt anything.. The bassmaster tournament on the st. johns I think it was, they were making 70 mile runs and having to fuel up half way each morning and afternoon.

Usually running at mid-range 38-4200 is the best fuel economy, but yamaha recommends 5000-6000 for a reason I suppose.

[SLE]

Originally Posted by Kevin23

...................................
Usually running at mid-range 38-4200 is the best fuel economy, but yamaha recommends 5000-6000 for a reason I suppose.

The recommended operating RPM for any outboard is based on the RPM you should see when running WOT. It doesn't mean they recommend you run it there all of the time. Anything below the upper posted limit (6000 in this case) is fine if you just cruising.

[Damascus]

You have a few options here depending on your needs. The rev4 17P will lift the stern if you frequently have passengers in the jump seats or you try a 19P Tempest. I have tried several props on my 1850RS 175ProXS. They included a 21P enertia, 19P Tempest (blueprinted), 19P Rev4 (blueprinted) and finally a 20P bravo1 FS. The Tempest ran at 53mph @ 6000rpm, good hole shot good bowlift great grip maximum use of jackplate and trim. Rev4 52mph @ 5950rpm, good hole shot good stern lift with good use of jackplate and trim. 21P enertia 52mph @5800 average hole shot prop blows out early with trim and height. The 20P Bravo runs 54mph @ 5950rpm has good hole shot carries load very well and grips very good regardless of trim and jackplate height the key feature is that i could still hit the same speeds and rpms with a full live well. Note i run at 900ft above sea level all speeds are GPS and rpm from smartcraft gauge.

[zogman]

Yep, Got to try the 17P Yamaha Reliance Prop. Guess I will stick with that.
It turned 6100 rpm and 43 mph. Still came up on plane quickly. Thanks Guys for all the info. I now cruise at 36 mph and 5000 rpm.

[Minnie Man]

Zogman, will you time how long it takes you to get on plane? And at what speed you are on plane? My boat came stock with the 19 reliance but I swapped to a 4 blade. Lost 3-4mph on top end but got my rpm up.

Sent from my SAMSUNG-SM-G930A using Tapatalk

[yarcraft91]

Originally Posted by zogman

Yep, Got to try the 17P Yamaha Reliance Prop. Guess I will stick with that.
It turned 6100 rpm and 43 mph. Still came up on plane quickly. Thanks Guys for all the info. I now cruise at 36 mph and 5000 rpm.

I'm a bit surprised you aren't seeing more speed. I'm running a 25 YO Johnson 2-stroke 120 outboard on a 19' Yarcraft and get the same WOT speed- 43 mph. The boat is rated for 185 hp, but jumps up on plane with the 120. Maybe your rig is a lot heavier than mine.

My typical cruising speed is 30 mph at 4000 rpm and I've been making 10+ mile rums at that speed ever since I bought this rig new in 1991. It's propped for near-max rated rpm at WOT and that has worked well for me.

[last chance]

yea get the 17p you'll be glad you did. the 17p will raise your rpm's about 400 and will work wonders on your hole shot.

[zogman]

Originally Posted by Minnie Man

Zogman, will you time how long it takes you to get on plane? And at what speed you are on plane? My boat came stock with the 19 reliance but I swapped to a 4 blade. Lost 3-4mph on top end but got my rpm up.

Sent from my SAMSUNG-SM-G930A using Tapatalk

I am at the Angle now so I should get a chance to time it in the next day or two. My boat came with the 19 P Reliance

[zogman]

Originally Posted by Minnie Man

Zogman, will you time how long it takes you to get on plane? And at what speed you are on plane? My boat came stock with the 19 reliance but I swapped to a 4 blade. Lost 3-4mph on top end but got my rpm up.

Sent from my SAMSUNG-SM-G930A using Tapatalk

I haven't timed it yet. Keep forgetting the watch. Seems to start leveling at 16 or 17 mph. It is always on full plane at 20 mph.

Timed it and it took about 7 seconds.

What 4 blade are you running???

[Minnie Man]

I am running a Rev 4 17p. Better out of the whole but I came from an etec so always wanting more.