Making the switch.... Things to consider

[ClassicCoke]

I have a 1990 Key West DC that was repowered in 2004 with a new (at that time) yamaha 2 stroke 90hp motor. Due to recent issues with the boat itself (gas tank leak-cost more to repair than boat is worth), i am considering buying a older used pontoon boat without a motor and switching my yamaha out and putting it on a pontoon boat. Ive boated my entire life but it was always on the coast, never in a pontoon boat in a lake (where i do all my boating now).

My question is, will this motor be compatible on a standard pontoon boat? model 90 TLRC . will the shaft be long enough to reach the water properly?

Are there general items to inspect on used pontoon boats when shopping around? They seems like pretty basic boats but having not spent much time pontoons in the past, wanted to hear from the experts as to their thoughts.

Tks

 

[HotTommy]

The commonly quoted rule of thumb is that the anti-cavitation plate on your motor should be roughly even with the bottom of the engine pod. So, measure the distance from the transom mount to the cavitation plate on your engine and compare that with the distance from the top of the transom to the bottom of the pod on any boat you consider.

Pontoon boats are pretty simple and I'm no expert, but I did refurbish a 25 year old pontoon boat two years ago. Here's what I'd look for.

1. A valid title and good VIN number (aft starboard usually).
2. Pontoons with no significant (leak causing) damage. If the boat is in the water, see if it leans to one side. If it is out of the water, remove the plug at the back of each pontoon and check for water.
3. A solid deck with no soft spots. It's not hard to replace the deck boards, but it is a lot of work.
4. If the crossmembers (aluminum beams between the pontoons) are visible, check them for cracks or signs of damage.
5. Inspect the engine pod and transom for cracks at joints and mounting points.
6. Inspect flooring, furniture, fences, etc. for signs they will need to be replaced soon.
7. Condition of the top if it has one.

You'd have to be very lucky for the engine controls and gauges on the boat to work with your engine. I'd consider a boat that was compatible with your engine to be a big plus. Three log boats and those with lifting strakes on the logs are also desirable, but likely more expensive. And if you'll need a trailer, it'll likely cost less if you buy it with the boat than separately. .. Good luck with the hunt.

 

[rogerwa]

So long as the motor is not a short shaft (I'm not srue that is even available) you shold be able to mount it. You may need different length cables for the controls and the steering cable should already be mounted. You will need to re-prop down several pitches most likely to achieve the proper WOT.

On a used pontoon the most important thing is the condition of the tubes, the frame mounts, and the frame itself. Everything else is either aesthetic or replaceable. The deck is ususally made out of plywood and can be replaced, along with carpet and everything else above it. The only consideration is the amount of purchase vs the cost of fixing. You don't have the issues of hidden rot or waterlogged transoms or anything like that. even if you tubes have leaks they can be fixed/welded fairly cheaply.

I would focus on getting the largest tubes you can - at least 23-25".

 

[ClassicCoke]

Great tips.

I would take the controls and steering from my current boat and put on the new pontoon boat (new to me at least). I have seastar steering and plenty of length on my throttle cables,.... so i should be ok.

I've read about structural issues in relation to the motor mounts--- any thing to look out for on these mounts? other than obvious cracks/weld breaks/etc...

Tks
Will

 

[rogerwa]

The rear tube mounts can sometime crack and let water in.. Not sure you would find that without a pressure test as it is the flexing that opens the crack. If you are concerned about this you can have them pressure tested. Other things should be pretty obvious. Just ensure the target toon can handle your OB HP.

 

[Jeep Man]

Your 90 should be good for most common lengths, providing it's a 20" shaft. Your motor would be best on a 20' or 22'. You will definitely be re-propping, most likely to an 11 or 13p. Generally age isn't a factor where condition certainly is.

 

[ClassicCoke]

Generally speaking, how interchangable is the 'generic' pontoon seating sets that i see on websites like overtons and the such? Looking at some used pontoon boats that are essentially just the toons and deck (ie needing complete seating sets installed). Didnt know if they are designed to work with only one model/type of toon.

Tks.

 

[rogerwa]

Generally, toon decks are 8' wide, some are 8.5'. These sets usually accomodate these standard widths. With an open deck you can customize as much as you want using the individual pieces or buying a set. They are not boat specific.

Often these are great upgrades when your old furniture is plywood and you can upgrade to the plastic bases.

 

[HotTommy]

I bought replacement seats for my boat from one of the popular sites. Just measure the spaces you have to fill and pick the sizes that fit as you wish. The only thing to look out for is that the corners on the furniture are nearly square while the corners made by my fences are more rounded. That kept the furniture from sliding all the way back against the fence in some spots, but it wasn't a serious problem.

 

[ClassicCoke]

I know they are many factors that go into it.... but what kinda top speed, for lets say the average 18-20-22 foot pontoon boat for the 90 hp yamaha 2 stroke that i am considering putting on it? I understand that alot of assumptions/variables go into this but not having spent much time on a pontoon boat, but many many hours on boats in general, just trying to get ballpark figures.

TKS

 

[HotTommy]

My 25 year old 24' two toon boat came to me with a 90 HP 2-cycle outboard on it. My usual load was two adults and three or four teens/kids, ice chest, etc. Straight ahead with no wind the top speed was about 21 MPH. Towing a tube it slowed to 19 and in extended turns it fell to 12-13. After I replaced the 90 with a 150 HP engine, all those speeds went up about 7 MPH, and my fuel usage nearly doubled.

 

[ClassicCoke]

just what i was looking for. tks