Re-power 28hp to 45hp

[hillbilly0614]

Sorry if this is a FAQ. Friend at work has a 45 HP Chrysler motor off a pontoon boat he is converting into a dock for his lake house he doesn't need the motor was thinking about buying for $300 to re-power my 21 ft Northwood pontoon. Boat is rated up to a 40hp I know DNR / police insurance I could get in trouble but figured an extra 5hp over the max allowed rating probably won't rip the transom off or anything too severe. I guess my thought is the price is cheap enough is it worth it for the extra horses? Would the performance increase be worth it? How much extra power/performance could I expect to see going from an Evinrude 28spl to a Chrysler 45? Again sorry if this has been asked before

 

[ahicks]

2 thoughts. First, you may notice a performance increase, but it's not going to be much.
Second, many don't think much of the Chrysler line of engines.

 

[ezmobee]

Parts and service are difficult to find for Chryslers and that's only going to get worse. If your current 28 is a 1986 or newer it's prop rated horsepower while the old Chrysler is crank rated. So they may be closer in HP than 17. $300 is probably top dollar for a small Chrysler. If it was me, I wouldn't do it.

 

[HotTommy]

In theory, a 60% increase in horsepower could generate a 25% increase in top speed. So, for example, if your top speed before were 9-10 MPH, it would go to about 12 MPH. ... Personally, if your current engine runs well, I'd pass for the reasons mentioned above.

 

[lmuss53]

One more vote to pass, the 28 is a newer model and is more serviceable and reliable. The old 45 just does not have enough to offer to make the swap worthwhile.

 

[hillbilly0614]

Thanks for the input. I was reading about the motors themselves a little and found much of the same as stated here. May look for a 50 HP Mercury possibly. Or see if my dad is will to swap engines with me. His boat is a 16ft alumnacraft fishing boat with a 60 Johnson that thing screams with that motor on it. I just worry about the max HP rating on the hull plate sure I can reinforce the transom and such but the plate still says 40 so if I get stopped or heaven forbid an accident I would be in trouble idk? Just looking to get a little more performance out of the boat. I know, I know it's a pontoon it's not meant for speed. Maybe I should just stick with the original plan to buy a 3 person jet ski for the tube. But then I'm back to my original dilemma 2 boats 2 trailers 1 tow vehicle.

 

[hillbilly0614]

Boat show is this weekend here in Milwaukee so might just have to pop in and pick some brains oh and dream about all the stuff I can't afford

 

[ahicks]

Hillbilly, you're going to need more power than you are talking about for skiing. More likely 75-90hp at the very least - to pull kids!

 

[Ike-110722]

Ahicks is right. Bad idea. You are not just talking way overpowered, you are talking a big increase in weight on the stern, a lot more fuel usage, not to mention that you are probably going to get a ticket from the state or local water cops. If you want to pull skiers get a different boat.

 

[hillbilly0614]

More so only a tube probably not waterskiing at least not yet anyway. Yea I think I'm just going to start looking at a 3 person jet ski like the original plan I had.

 

[Scott Danforth]

do some reading. not much performance gains on a pontoon unless you get it up on plane. a few have gone from 50hp to 90 or 115 with almost zero increase in mph, however just more noise and fuel.

a pontoon is a displacement hull. it moves at hull speed unless you get enough power to it to get out of the hole and up on plane. a tri-toon with lifting strakes is the best for that.

I wouldnt do it for the resons mentioned.

 

[lmuss53]

If you get the ski you can store it somewhere close to where you launch and cut back on the tow issues, maybe put a hitch on second car, just about anything can tow a jetski a few miles.

It's tough to get much performance from a pontoon that isn't designed for or legal for higher HP motors, I think you'll find that a frustrating experience. (Been there).

I use my pontoon for laying around on and my aluminum v hull for fishing and any tube towing I may do.

Maybe you can make a deal to borrow Dad's boat to tow the tube.

 

[hillbilly0614]

For sure... Still thinking I'm going to get a 3 person ski for the tube. Double towing is allowed here in Wisconsin only deal is that I'm over the 3000lb weight limit so I will have to invest in a set of trailer brakes. I've found kits for about $400. Most likey will throw the ski in truck bed most of the time except for when the camper is in it. So majority of time it will be brought to lake in truck bed when camping it will be double towed