Are Tohatsu/Merc Motors Over Propped ?

[Sea Rider]

Was needing urgently to buy a new 2 stroke 25 HP motor, Tohatsu, Yam, Suzuki are out of stock untill further notice, C-19 has screwed all their production line. Last resource, went to our local Merc's dealer store to inquire for such motor which as you know it's a rebadged Tohatsu 25 HP model. To my surprise came factory delivered with a 13 pitch prop which will only rev at max 5 K wot revs which is the bare MIN rpm factory stated powering whatever floats.

Both the 25 & 30 motors are the only ones in the portable to medium light HP range that needs an urgent prop maximization right out of the box if wanting your light combo to run towards its max 5800 wot rpm range or keep running an ill dog towards the lugging side with its related dire consequences without knowing about it.

At $ 3,199.00 listed price will need to add $ 150.00 for a 3 blade alum 11 pitch prop. Is $ 3,349.00 still an attractive or non attractive purchase price to you ? Add $ 8.00 extra to replace the 25 HP carb's intake gasket along a + 5 deg time advance setting to count with a greyhound 30 HP motor...

Happy Boating
​

 

[flyingscott]

I would be more curious to know what boat it is on?

 

[Sea Rider]

I would be more curious to know what boat it is on?

14/15 footer light boats with light loads, imagine heavier ones...

Happy Boating

 

[flyingscott]

I would question the rating on the motor if a 25 hp struggles to turn a 13" pitch prop.

 

[Sea Rider]

I would question the rating on the motor if a 25 hp struggles to turn a 13" pitch prop.

These 25-30 HP Tohatsu/Merc motors doesn't struggle to turn 13 pitch props, simply planes large light boats at their min wot lugging rpm range which is 5000 rpm. My 30 well propped with an 11 pitch turns 5800 easy peasy and iterally jumps on plane my light applications at bit more than half throttle.

Know that situation well after selling more than 30 of them all of which were tached powering light applications so to state that awful scenario. In real boating world no one tachs their small to medium light motors on whatever floats, there's the usual mental issue that states : if powers my boat well I'm happy, but its a day/night water performance difference powering well and powering top, it's entirely up to each one if deciding to repitch or not...

Happy Boating​

 

[flyingscott]

These 25-30 HP Tohatsu/Merc motors doesn't struggle to turn 13 pitch props, simply planes large light boats at their min wot lugging rpm range which is 5000 rpm. My 30 well propped with an 11 pitch turns 5800 easy peasy and iterally jumps on plane my light applications at bit more than half throttle.

Know that situation well after selling more than 30 of them all of which were tached powering light applications so to state that awful scenario. In real boating world no one tachs their small to medium light motors on whatever floats, there's the usual mental issue that states : if powers my boat well I'm happy, but its a day/night water performance difference powering well and powering top, it's entirely up to each one if deciding to repitch or not...

Happy Boating​

My 2 strk 25 hp merc spins a 13" pitch prop to 6000 on light hulls. 2 strk Evinrude the same. Something is suspect on the power rating or an over geared lower unit.

 

[Sea Rider]

My 2 strk 25 hp merc spins a 13" pitch prop to 6000 on light hulls. 2 strk Evinrude the same. Something is suspect on the power rating or an over geared lower unit.

Is your 25 HP a Merc branded motor or a rebadged 25 Yam one ? If so could account for an over geared lower unit, prop style ? The gear ratio for both 25 & 30 HP models is 1.92:1 (12:23) Tohatsu seems wanting to play extremely safe powering their motors with factory delivered over pitched props. What's funny is that Merc's dealer is offering an OEM 3 blade 11 pitch prop as an extra at around $ 148.00.

Happy Boating​

 

[flyingscott]

Mine is a real Merc 25. The same motor that was put on many fiberglass Lakeland boats and never had a problem. Yamaha never made a Merc 25 Tohatsu did. It's not that uncommon for the smaller 4 strks to be down on power.

 

[Sea Rider]

Yamaha never made a Merc 25 Tohatsu did. It's not that uncommon for the smaller 4 strks to be down on power.

Actually what stated corresponds to 2 stroke Tohhatsu motors, not 4 stroke, both needs a prop maximization for any combo to run top, have seen no 2 or 4 stroke motor being factory delivered with under pitched props, have tached several just for curiosity purposes that accounts for that..

Happy Boating​