Poor performing 4 stroke Yamaha

New here... I'm sure you get a lot of these but here goes. Any help is appreciated.

I own this boat:

http://www.g3boats.com/Angler_V162_T

Mine is a 2009 model, but you get the idea. Aluminum Deep-V, wide body. Don't know the exact weight, but it has to be close to 2000 pounds give or take. I bought it used. It came with a 2009 Yamaha 60HP 4 stroke.

This thing is a dog. Zero hole shot even with it lightly loaded (just me and my 10 year old and our fishing stuff), takes a long time to get on plane, and won't get above 24 MPH @ 5100 RPM's at that loading. When loaded close to capacity, the boat will not get on plane at all and the best it will do is 9 MPH @ approximately 4200 RPM's.

The prop is an aluminum 10 3/8x13. I don't know the manufacturer, but I suspect it is a standard Yamaha prop. Stamped on the inside is 10 3/8x13-G. I have no idea what the G designation is.

The motor is mounted to the transom in the lowest possible position. The only way to adjust is up. The cavitation plate is just about in line with the keel...maybe a tad lower.

I think I have a prop with too much pitch and/or the motor is mounted in the wrong position. I don't know squat about boat setup, but it seems to me that I should be getting better performance in terms of both top end speed and engine RPM's out of this boat.

Any suggestions are appreciated. Cheers...Jim

Re: Poor performing 4 stroke Yamaha

The ventilation plate should be even with or slightly above the keel. It may help to raise it a little. Also, where is the trim pin installed. You may need to trim out a little more than you are now.

Are you taking speed readings with a GPS? Fish finder speeds are horribly inaccurate.

Remember that weight distribution will have a large impact on a boat like yours. Is it a tiller steer as in the pic that you linked? The motor, gas tank, battery, and you all in the stern? See if you can get more weight in to the bow. If you can move the battery and gas forward, you might be better balanced.

Re: Poor performing 4 stroke Yamaha

All good suggestions above.Where is the built in tank?Live well etc.
Do you trim in(down) for hole shot?The 13" prop is way down the list with
only 3 smaller props.11 10 and 9.There are 12 props above.So its surely down in the load prop range.I think that setup should have at least a 10 sec. hole shot A pontoon prop would be a 10 or 11"And they are impossible to push. I think I would check that the carb opens all the way. Be sure it is tuned correctly.
All plug wires hooked up.

Re: Poor performing 4 stroke Yamaha

wifisher said:

The ventilation plate should be even with or slightly above the keel. It may help to raise it a little. Also, where is the trim pin installed. You may need to trim out a little more than you are now.

Are you taking speed readings with a GPS? Fish finder speeds are horribly inaccurate.

Remember that weight distribution will have a large impact on a boat like yours. Is it a tiller steer as in the pic that you linked? The motor, gas tank, battery, and you all in the stern? See if you can get more weight in to the bow. If you can move the battery and gas forward, you might be better balanced.

Click to expand...

Thanks for the response. The boat did not come with a trim pin. This is my first boat with hydraulic tilt. I didn't realize that I needed to have a pin inserted. As far as the speed, I am reading MPH from the GPS, but it's been my experience that this particular GPS is pretty accurate. I tested it against my car speedo and it is close enough that I'm confident with the numbers.

I have been concerned about the weight distribution. It is a tiller steer, so I am seated in the back. The battery compartment is towards the stern as you suspected. The fuel tank is long and rectangular. It is located in the middle of the boat and extends from directly in front of the rear seat position up to the beginning of the casting platform, so I do have a lot of weight towards the stern.

I was hoping there was a motor/prop setup problem that could easily solve my problem, but it sounds like you are going the weight distribution route which isn't nearly as easy to solve. I hate the idea of replacing the tank with a smaller unit that I can shove more towards the bow, but it makes sense. The battery relocation won't be much easier.

The motor is fuel injected with low hours on it. I had it inspected and it checked out okay. Will the poor weight distribution contribute to the engine not reaching max RPM's? My manual says operating range is up to 6000 RPM's, but I've never got close to that. To add insult to injury, I've looked at a number of performance bulletins published by Yamaha using boat and motor combinations similar to mine and they all show higher RPM's and more top speed.

Thanks again for the response.

Re: Poor performing 4 stroke Yamaha

steelespike said:

All good suggestions above.Where is the built in tank?Live well etc.
Do you trim in(down) for hole shot?The 13" prop is way down the list with
only 3 smaller props.11 10 and 9.There are 12 props above.So its surely down in the load prop range.I think that setup should have at least a 10 sec. hole shot A pontoon prop would be a 10 or 11"And they are impossible to push. I think I would check that the carb opens all the way. Be sure it is tuned correctly.
All plug wires hooked up.

Click to expand...

I have two livewells, one fore and one aft, but they never get used. I do trim down for the hole shot, then as the boat gets on plane I adjust the trim up.

Is it worth it to try a prop with less pitch or am I just throwing good money after bad since we've already established that weight distribution is an issue? Thanks for your response.

Re: Poor performing 4 stroke Yamaha

While weight distribution could help I think you may have a performance issue.
Compare boat styles and their prop sizes to yours.I feel that a 13" prop should easily reach
near your 6,000 max rpm rating. A V162 w a 70hp w a 14" prop over 2,000 lbs has a 5.35 second hole shot
and 30 mph at 6100 rpm Its hard to believe a 60 couldn't come close to that with a 13" prop.
Your 60 is 30 lbs lighter easing the stern weight a little.
I really feel the motor has an issue could be a dead injector,also just because its injected doesn't mean the throttle opens all the way.Motor may have timing issues.
I wouldn't be surprised it might struggle with a full load and may require a little less prop.

Re: Poor performing 4 stroke Yamaha

steelespike said:

While weight distribution could help I think you may have a performance issue.
Compare boat styles and their prop sizes to yours.I feel that a 13" prop should easily reach
near your 6,000 max rpm rating. A V162 w a 70hp w a 14" prop over 2,000 lbs has a 5.35 second hole shot
and 30 mph at 6100 rpm Its hard to believe a 60 couldn't come close to that with a 13" prop.
Your 60 is 30 lbs lighter easing the stern weight a little.
I really feel the motor has an issue could be a dead injector,also just because its injected doesn't mean the throttle opens all the way.Motor may have timing issues.
I wouldn't be surprised it might struggle with a full load and may require a little less prop.

Click to expand...

Thanks. You obviously looked at one of the same performance bulletins that I did and understand my frustration. Maybe I should get this thing to the shop.

Re: Poor performing 4 stroke Yamaha

You know I took another look and a 60 with about 1500 to 1600 lb. setup is running a 13.
Maybe you do need to go to a 11 or 12" pitch.I also notice they do run the V162C with a 90.
That puts your 60 on the ragged edge of the minimum suggested for a boat with a 90 rating.
If the tach is accurate you need to make up about 900 rpm Wouldn't hurt to raise the motor.
You should try to raise the motor to a point just before venting becomes a problem.
You could pick up a couple of hundred rpm and a very slight help with hole shot.
Once that is set then a prop selection. Consider a 4 blade 11"to improve hole shot and help to stay on plane with reduced throttle.The 4 may also resist venting better.The 60 has a 1.85 gear ratio while the 70 is about 2.33. A higher number ratio can turn a higher pitch.May explain why the 70 seems to do so much better with a 13" pitch.

Re: Poor performing 4 stroke Yamaha

steelespike said:

You know I took another look and a 60 with about 1500 to 1600 lb. setup is running a 13.
Maybe you do need to go to a 11 or 12" pitch.I also notice they do run the V162C with a 90.
That puts your 60 on the ragged edge of the minimum suggested for a boat with a 90 rating.
If the tach is accurate you need to make up about 900 rpm Wouldn't hurt to raise the motor.
You should try to raise the motor to a point just before venting becomes a problem.
You could pick up a couple of hundred rpm and a very slight help with hole shot.
Once that is set then a prop selection. Consider a 4 blade 11"to improve hole shot and help to stay on plane with reduced throttle.The 4 may also resist venting better.The 60 has a 1.85 gear ratio while the 70 is about 2.33. A higher number ratio can turn a higher pitch.May explain why the 70 seems to do so much better with a 13" pitch.

Click to expand...

Thanks again for your response. Lot's of good info in your last post.

As far as the prop goes, when I reduce the pitch, should I stay with the same diameter?

Re: Poor performing 4 stroke Yamaha

Diameter usually just follows the design. Generally as pitch goes up diameter goes down
and as pitch goes down diameter goes up. Don't sweat the diameter as long as the prop is intended for your motor. If a 4 blade proves difficult to find An 11" 3 blade should help as well.

Re: Poor performing 4 stroke Yamaha

Thanks again. I appreciate your input.

I forwarded this to G3 yesterday and they just got back to me. They are telling me that the standard setup for my boat/motor combination is a 10 5/8 x 12 prop with the motor mounted in the lowest position. The tech feels like this change will help me tremendously.

Me...I'm not so sure.

Re: Poor performing 4 stroke Yamaha

Its hard to believe that a 1" pitch change will make up anything close to
the 900 rpm you need. Might gain 200 maybe 300.Probably won't hurt anything but will be slightly less responsive with a load then an 11".He should know what he's doing.

Re: Poor performing 4 stroke Yamaha

That's what I was thinking too. From the reading I've done on props, a 1" pitch change moves the RPM's about 200.

Re: Poor performing 4 stroke Yamaha

I did some very rough numbers and it appears that if my figures are riight your 24 mph at 5100
is right. So the tach and speedo seem to be accurate.
I looked at the performance reports again and see that the 60 w a 13" on a V170 at about 2,000lbs turns 5900 rpm at over 30 mph.I don't get it; is the V162 a really deep V or poor weight distribution or does your motor have an issue.Even though most of the boats were lighter
they were all tested with a 13" prop with rpm close to that 6,000 figure.
A 50 w the same gear ratio on a V170 at 1998lbs runs a 12" at 5700 rpm and 31.9 mph
Again it appears the motor has issues or the V162 is some how much different than the V170.
I think a motor check before any prop changes.Maybe print out the tests and show them to the Yamaha dealer.

Re: Poor performing 4 stroke Yamaha

Thanks. We've gone full circle on this and came back to a potential engine issue.

I don't know how much difference there is between the deep V models. I'm going to get myself another prop to start with. Can't hurt to have an extra one anyway. If that doesn't help, then it's off to the shop to see what's happening. When I get more time (think off season), I'll try to redistribute some of this weight.

Thanks again. Hopefully I can get this ironed out with some of the things you've suggested. You've been about the only one willing to help me out. It's appreciated.

Jim

Re: Poor performing 4 stroke Yamaha

Cat- I just saw the thread and have read through it and it doesn't make sense to me. While that boat is very wide and quite heavy for a 16 footer I believe you should be getting much better performance out of it. My 16' SeaNymph, while not being anywhere close to the size your G3 is, still weighed in at 1370 lbs. With a 50hp 2-stroke my top speed was 35 and holeshot as such was fine. And I ran a 17 pitch prop!
While steele has obviously done some research and has data, I have to question the factory's advise to run the engine in the lowest hole. Since your anti-vent plate is below the keel, you are adding drag to the boat. If you bring the engine up on the transom and raise the plate to be about 1"to 1 1/2" above the keel that is the ideal location. The L/U is plenty deep enough to get everything it needs and you eliminate some drag as well. That can raise RPM by a couple hundred RPM believe it or not.
As for the rest, I'm not a 4-stroke guru but 60 horses are 60 horses, right???

Oh- forgot something. If you have hydraulic tilt you'll not have a pin so ignore that bit of info.

UFM82

Re: Poor performing 4 stroke Yamaha

As a follow up, I put a 3 blade 10 pitch prop on and it has made a big difference. The boat gets on plane in a few seconds even when loaded down with gear and stays there very nicely at reduced throttle. I can easily get the engine to rev to 6000 RPM's now and the prop just seems to bite much better and feels more suited to this boat/motor combination. The hole shot will now snap you back and towing people around on a tube works great.

Not much difference in top end speed, but I'm okay with that. I was more concerned with getting on plane and staying there. This prop has done it.

In an attempt to get a little more speed, I might still raise the motor up a notch and get a smaller gas tank that I can move farther forward once the snow starts blowing, but for now all is well.

Wanted to say thanks to those that have participated in this thread.

Re: Poor performing 4 stroke Yamaha

One other thing I didn't mention. I tried using a 4 blade 10 pitch prop and it was no better than the original 10 3/8x13 three blade. Slightly faster to plane...maybe, but lower RPM's than the original and less top end speed. That prop lasted all of one trip.