question with performance yamaha F50 vs suzuki DF 50 please help me

[kenairiver$$$]

I had a 2007 DF 50 pushed my boat great would travel about 30-34 mph downriver, i recently switched to a yamaha F50. lost a lot of top end i travel about 25 - 30 mph downriver. both situations i was by myself..now the big issue is when i have 4 people in my boat i am now having trouble getting on step where as with the suzuki i never had an issue. curious if i should go larger pitch or smaller pitch to push the load. or should i buy the T50 lower unit (high thrust). the gear ratio for the F50 is 1.85:1 the suzuki that i no longer have is 2.27:1 the T50 is 2.33:1. I think buying a prop would be easiest and most cost effective solution but im also looking to gain my top end that i lost. If anyone has any ideas or questions please help me out thank you​

 

[99yam40]

what were and are the RPMs?
what props were being used?

 

[charleso]

You may want to check the height the Yamaha is mounted at versus the Suzuki. I have an F60 on my boat. Have been researching options because it will not run over the low 5000 RPM range. I have determined that not only is the motor over propped, but also mounted too low on the transom.

 

[ondarvr]

I can't imagine buying a new lower unit would be cost effective at all, easier to sell the Yamaha and buy another Suzuki.

​There was a test comparison a while back on 50 hp outboards, and from what I remember the Yamaha was at the back of the pack in power and speed.

 

[kenairiver$$$]

i couldn't tell you the exact rpms but at full throttle trying to get on plane with a load it be anywhere from 4700 to 5500 i could hear the motor wanting to go but it just wont push. and i just plow a huge wake.. ive been guiding for 8 years and fishing professionally for 15, and i could literally hear the motor hit its max rpm while i was trimming out to no avail. I also have a jack plate and i have adjusted the height of the motor up, and down. there is a sweet spot i find and it will eventually get me on plane after about 5 minutes of pushing water. this is only happening with a heavier load of ppl... say 4 guys over 200lbs..... the prop i have is an 11 5/8x11 on the yam, and the suzuki i had a 11 5/8 x 12. the Suzuki was a **** motor with a **** dealer in my area they never had time to help me i drive by their shop all the time im surprised they are still there looks like a ghost town..... they were overpriced and had no clue about anything thumbs up there asses. im so glad i switched to the yamaha they answer the phone and actually give input. but before i go in there i just wanted a little more help and knowledge before making a decision on what to do. the way i see it theres two choices find the right prop or go with the T lower unit. what do you guys think?

 

[ondarvr]

You can't tell the RPMs by listening, you need a tach.

A new lower unit is probably more than a $1,000.00 , plus another prop, if you can't do the work then it's even more.

 

[99yam40]

what boat do you have this motor on?
what HP is it rated for?

seems the T motors are high trust and used on heavy boats/loads

 

[kenairiver$$$]

my boat is most similair to a willie predator...its a 20 ft aluminum river sled with a slight V kenai river regulations allow only a 50 hp maximum. Its rated for a 110 hp. The T lower unit is 2700 and some change. i may just buy the 9 pitch prop see what happens its about 127 on amazon.... i know people can talk about propping for days. i might get a tach installed but those are 350$ and i looked at the wiring diagram and i will have it professionally done. the older tachs are easy but these new ones look like a nightmare..

 

[ondarvr]

You can buy a simple tach on eBay for about $11.00, the pricier ones are $30.00, it takes about 2 minutes to mount it. Or you can borrow a timing light from someone.

 

[99yam40]

my boat is most similair to a willie predator...its a 20 ft aluminum river sled with a slight V kenai river regulations allow only a 50 hp maximum. Its rated for a 110 hp. The T lower unit is 2700 and some change. i may just buy the 9 pitch prop see what happens its about 127 on amazon.... i know people can talk about propping for days. i might get a tach installed but those are 350$ and i looked at the wiring diagram and i will have it professionally done. the older tachs are easy but these new ones look like a nightmare..

yea, sounds like your way under the proper HP for the boat.

less prop pitch or size like you said would be the less costly,
the T motors turned a larger prop at less RPM to keep the motors RPM up in the higher torque range of the motor with the different gear ratio

probably should have bought the T 50

 

[ondarvr]

Since the change from 35hp to 50hp on the Kenai happened several years ago, the locals should know exactly how to set up a Yamaha for your type of boat. There are hundreds of boats similar to yours on the river and a good number have Yamaha's (I've been on them), so they will know.