Repowering 20' Weeres Pontoon... Need Advice

[FlyboyTR]

Hello,
I am a first time poster...long time reader. I continue to be amazed at the amount of knowledge that is available on these forums.

We have a 2006 20' Weeres pontoon. It was originally powered by a 50 HP Yamaha 2-stroke. With two of us on board, and properly trimmed it would run 20-21 MPH. No lifting strakes, etc and the bottom is not skinned. We live on the Gulf of Mexico and use the toon primarily for fishing, both inshore and occasionally in the Gulf. We wanted to repower the toon so we could have a little more top end speed if/when needed, and be able to cruise a little faster when loaded. ...there is nothing exciting about running from bad weather at 15 MPH with guests on board!

We sold our 50 Yamaha this past weekend...so now it is time for action!

This model carries a rating of 50-90 HP. There are no specs as to max weight of the engine itself. The little 50 weighed 189 lbs/dry. I have been looking at motors in the 90-100 HP range, both 2 & 4 stroke. I am looking at later model used engines and since I already have Yamaha controls, etc... I want to stay with Yamaha. Please take a look at the following numbers, based upon what I have found:

90 HP, 2-stroke, 261 lbs/dry
90 HP, 4-stroke, 370 lbs/dry
100 HP, 4-stroke, 356 lbs/dry

While I have no problems with pushing the HP past the rated 90, the 100 HP/4-stroke looks to be the better choice for weight, HP and fuel burn. I have also considered the fact that I may want to move my fuel and batteries forward for better static weight distribution...but that is a whole different subject. Your comments, questions and recommendations would be appreciated. Thanks!

 

[EGlideRider]

Re: Repowering 20' Weeres Pontoon... Need Advice

You didn't include engine years or prices which could greatly influence decisions.

Assuming the years and prices are similar, I would go with the 90 2-stroke. The extra 10 horses of the 100 will provide no noticeable speed increase and may present insurance issues. The 4-stroke would be a viable option but I happen to prefer 2 strokes because of lower maintenance costs.

Welcome to the forum and let us know your decision.

 

[halfmoa]

Re: Repowering 20' Weeres Pontoon... Need Advice

 

[FlyboyTR]

Re: Repowering 20' Weeres Pontoon... Need Advice

EGlide,
Thanks for the "Welcome" ...glad to be here!

All the engines are 2002 and newer with pricing from $2,500 - $4,000. I did not even think about the insurance thing by having HP in excess of its rating. Good point! Thanks! I am concerned about fuel burn with the larger 2-stroke.

 

[The Rooster]

Re: Repowering 20' Weeres Pontoon... Need Advice

That's kind of a tough decision "Flyboy TR". I agree w/ Eglide about being careful when considering overpowering your toon. I also prefer the newer direct injected 2-strokes or 4-strokes. I don't believe Yamaha made a direct injected (HPDI) 2-stroke in your HP range. The 90 hp 2-stroke you are looking at is , I believe, carbed. In your case, I'd look hard at the 90 hp 4-stroke. Good luck !!!

 

[FlyboyTR]

Re: Repowering 20' Weeres Pontoon... Need Advice

I don't believe Yamaha made a direct injected (HPDI) 2-stroke in your HP range. The 90 hp 2-stroke you are looking at is , I believe, carbed. In your case, I'd look hard at the 90 hp 4-stroke. Good luck !!!

Thanks Rooster. Correct, nothing injected in the 90 HP 2-strokes. ...although, that would be nice!

 

[The Rooster]

Re: Repowering 20' Weeres Pontoon... Need Advice

Be careful "FlyboyTR" of this path you are about to undertake. First the upgrade to the 90 hp, then maybe a "waterglide" underneath the deck w/ some underskinning. Before you know it, you're flying along over 30 mph looking down your nose at those with merely 40-60 hp!!! Next, the dark side of "SPEED" takes control of your soul, and you begin to think about triple tube boats w/ V-6 power!!! Beware the dark side "Flyboy". All it got me was 9 more years of boat notes !!!

On a more serious note, since you guys like the toon and plan to keep it awhile, you might consider the underskinning if you can find it for cheap. You'll gain 1-2 mph and help protect everything underneath. Good luck!!!

 

[lncoop]

Re: Repowering 20' Weeres Pontoon... Need Advice

Based on what you've said I think you'd be happiest with the four stroke ninety. Those prices sound pretty good. Don't know what your reasoning is for insisting on a Yammy (not that that's a bad thing), but if you wanted to broaden your horizon a bit you might consider an E-TEC. Welcome aboard.

 

[FlyboyTR]

Re: Repowering 20' Weeres Pontoon... Need Advice

On a more serious note, since you guys like the toon and plan to keep it awhile, you might consider the underskinning if you can find it for cheap. You'll gain 1-2 mph and help protect everything underneath. Good luck!!!

There are times I wish I had a tritoon! ...already been looking at some of those hot-rod versions! ...just too much money for something to fish out of... maybe! I am very interested in the underskinning. I need to so some more research on that. Since a lot of running is in open water I am amazed at the impact the waves have when striking the cross beams. With the added weight of the larger motor, sitting deeper in the water, that may have to be the next project after the motor. Not sure about the Waterglide...sure would like to see one! Thanks again!

 

[FlyboyTR]

Re: Repowering 20' Weeres Pontoon... Need Advice

Based on what you've said I think you'd be happiest with the four stroke ninety. Those prices sound pretty good. Don't know what your reasoning is for insisting on a Yammy (not that that's a bad thing), but if you wanted to broaden your horizon a bit you might consider an E-TEC. Welcome aboard.

Thanks...Glad to be here! I have all the controls for the Yamaha...and I have a close friend that is a wrench turner and Yamaha's are his specialty. I have looked for an E-tec but did not find anything in the HP/price range I was wanting.

 

[steelespike]

Re: Repowering 20' Weeres Pontoon... Need Advice

I would stick with the 2 stroke. Much much less maintenance,fuel use is a wash
when researching fuel use be sure to note gph @ rpm/speed and actual mpg.
In my opinion the 2 stroke is under less stress.It produces a power pulse every revolution
Twice as many pulses at less impact per pulse The four stroke experiences twice as much impact at each power pulse.The 4 stroke has many many more moving parts. That 100lbs saving is signifigant.
Under certain conditions a 4 stroke "makes oil"sometimes requiring specific operating procedures.4 stroke requires valve adjustment,oil changes, and likely timing belt/chain replacement or repair.Depending on the valve system design a broken belt or chain could seriously damage the power head.

 

[FlyboyTR]

Re: Repowering 20' Weeres Pontoon... Need Advice

I would stick with the 2 stroke. Much much less maintenance,fuel use is a wash
when researching fuel use be sure to note gph @ rpm/speed and actual mpg.
In my opinion the 2 stroke is under less stress.It produces a power pulse every revolution
Twice as many pulses at less impact per pulse The four stroke experiences twice as much impact at each power pulse.The 4 stroke has many many more moving parts. That 100lbs saving is signifigant.
Under certain conditions a 4 stroke "makes oil"sometimes requiring specific operating procedures.4 stroke requires valve adjustment,oil changes, and likely timing belt/chain replacement or repair.Depending on the valve system design a broken belt or chain could seriously damage the power head.

Since most of our operation would not be at WOT and the weight savings...It's possible the 90 2-stroke would be the better choice. This would certainly remove the need to move fuel and batteries forward. In regards to the fuel burn being a wash...when compaired to 4-stroke maintenance, initial cost, etc. Good point. Thanks.

 

[5150abf]

Re: Repowering 20' Weeres Pontoon... Need Advice

I think any gain with the 100 would be lost to the extra 100 lbs it weights, especially on a smaller boat like yours.

I am with the 2 stroke also, less weight, same power, lower costs.

 

[EGlideRider]

Re: Repowering 20' Weeres Pontoon... Need Advice

Typical 4-stroke has 22 times more moving parts than does a 2-stroke........ This equates to more problems, more maintenance, more weight, and more money. Just maintain the proper fuel/oil ratio and the 2-stroke will outlive you.

 

[FlyboyTR]

Re: Repowering 20' Weeres Pontoon... Need Advice

OK...it looks like the two stroke has the most support! We do a lot of trolling/fishing. So our motor ends up idling for an extended period of time. Any concerns with the 90 and long idling times?

Thanks again to everyone for all the info and support...sincerely appreciated!

 

[EGlideRider]

Re: Repowering 20' Weeres Pontoon... Need Advice

A two-stroke will sometimes 'load-up' after long periods of idleing. That means the plugs may tend to exhibit signs of fouling such as rough idleing. If that occurs, simply knock it out of gear and rev the engine for a few seconds. And always try to make a power run back to the dock after long idleing periods.

 

[FlyboyTR]

Re: Repowering 20' Weeres Pontoon... Need Advice

EGliderider,
Thanks for that tip. I had been just gouging the throttle for a second or two. However...your method would certainly be less disruptive to the fishing...and to other around us.

 

[Jeep Man]

Re: Repowering 20' Weeres Pontoon... Need Advice

Welcome to the forum Flyboy. I have to side with the 4 stroke. First I would speak with you insurance co. and see if they would have an issue with a 10% overpower. Then I would speak to a Yammie dealer to confirm that the 90 is actually heavier than the 100. I have a 4 stroke and a 2 stroke, and I do NOT miss the smoke and smell of burning oil on the 2 stroke when trolling, AND, I do enjoy the fuel economy of the 4 stroke EFI.

 

[steelespike]

Re: Repowering 20' Weeres Pontoon... Need Advice

A 2002 motor must be oil injected should do well trolling.
One of the things that can cause a 4 stroke to make oil is trolling.

 

[FlyboyTR]

Re: Repowering 20' Weeres Pontoon... Need Advice

Welcome to the forum Flyboy. I have to side with the 4 stroke. First I would speak with you insurance co. and see if they would have an issue with a 10% overpower. Then I would speak to a Yammie dealer to confirm that the 90 is actually heavier than the 100. I have a 4 stroke and a 2 stroke, and I do NOT miss the smoke and smell of burning oil on the 2 stroke when trolling, AND, I do enjoy the fuel economy of the 4 stroke EFI.

Thanks...glad to be here. I contacted my insurance company this afternoon. They will not insure the toon if the motor is larger than what is posted by the manufacturer. The weight numbers were given to me by one of the local Yamaha shops. ...Still seems odd. Thanks for the input!