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Tcondra

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I have a Tohatsu 25 on a small 16 foot fishing pontoon. The boat and motor are brand new. Even under the best of conditions the boat only goes 8mph. The prop has a 9 pitch. Can I go to a different pitch and gain some speed? If so what prop and where can I find one. Thank You for any help
 
What is your RPM at WOT? That will determine whether you have the correct prop. What is your actual Tohatsu model?
 
Assuming your model is MFS25C. The WOT range is 5000-6000. The 30 hp motor is the same frame, but uses a different ECU. That version can go up to 6250. You want WOT RPM to be as close to 6000 as possible. If the USCG placard would allow, you would be much better off with a larger motor. For example, on a local Benningtom 22' tri-toon, we run a 150 hp motor. However, for your rig, you need some less pitch. Tohatsu sells a lower-pitched prop, which may get you a few hundred RPM more. Will that increase your top speed? A little. But you are really running too small a motor.
346B641065PROP 25&30 HP (10.2 DIA. X 8.3 PITCH)$135.52

I could ship one to you as soon as Thursday.
 
I think the salesman stretched the truth to sell us the boat. He claimed it would do 15 mph with this motor. He said 40 was the maximum for this boat but the Qwest site says 50. We may go to a bigger motor next season if we can get a decent trade in on our 25. The boat and motor ate both 2017 but Were still on the showroom floor. I may try a different prop but if I won't gain much not sure if it's worth it.
 
If you want any performance, you must run at least 80% of max USCG placard. In your case an MFS40. You only have about half of that now.
 
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