Yamaha high thrust pontoon only??

[Lefebvre]

An "expert" friend of mine tells me I made a big mistake buying a Yamaha High Thrust 50 HP (F50 TLRX62YL414966)used (excellent condition) for my fiberglass 18' x 6'wide (1,000 pounds). Says this is a pontoon only outboard and that excessive RPM will cause serious damage to motor and even burn it in five minutes. In addition, it will never give me a planing speed. Another friend says the same thing!<br /><br />Your opinion please friendly "experts"<br /><br />Guy<br /><br />p.s. Is my model #No significant in any way? A code?<br />=====================

 

[JB]

Re: Yamaha high thrust pontoon only??

Howdy, Lefebvre.<br /><br />Welcome to iboats. <br /><br />I disagree with your friend. Well, I mostly disagree with him.<br /><br />The High Thrust drive train was intended for heavy, low speed vessels like 'toons, barges and the like. But that doesn't make it a loser for running a boat like yours.<br /><br />The larger prop turning at lower speed "grips" the water better but also offers more drag at higher rpm.<br /><br />Your only real problem is selecting the correct pitch prop for driving your particular boat.<br /><br />Check out the advice on prop selection in the Engine FAQs section.<br /><br />Since this post has nothing to do with Electrics or electronics I will move it to Outboard Non-repair.<br /><br />Good luck.

 

[gotboostedvr6]

Re: Yamaha high thrust pontoon only??

lef,

how did it workout?

 

[Silvertip]

Re: Yamaha high thrust pontoon only??

I agree with JB. For example, Mercury 75 & 90 HP outboards use the same lower unit that a 40/50/60 HP Merc BigFoot uses. BigFoot is Mercury's acronym for Yamaha's Hi-Thrust. All you need to do is prop it correctly and it will be just fine.

 

[rodbolt]

Re: Yamaha high thrust pontoon only??

your model number indicates its a standard four stroke.
the T50 is the high thrust, F50 indicates standard.
the gear case is physically larger on the T model, the prop shaft is larger in diameter and the gear ration is numerically higher, usually about 2.38/1 as opposed to about 2/1.
the T model props cannot be swapped with the F models in the 50 hp range as the shft sizes are physically different, the T model uses the same shaft size as the larger 3 cylinders and the v and some inline four cylinders.
double check your model number. can ya post a pic of the gear case?
either way the T model can be correctly propped for a planing hull, its just less efficeint at planing speeds due to the larger case size.

 

[JB]

Re: Yamaha high thrust pontoon only??

Note the date of the thread, guys. 2005