Thundercat not going as fast as expected - help!!

[Aron50tohatsu]

Hello, i am new to forums but thought i would give it a chance!

I have a 2023 Aquarius Thundercat with a Tohatsu M50D2 shortshaft with new racing reeds and intake. Prop is a winrace 19 pitch cleaver and the over rev safety is not plugged in. And the engine is lifted 45mm from the top of the transom. The thing is… it Will only reach 50 knots exactly 1up and 42 knots 2up, is there something i am missing or is it just normal becouse i haven’t ported and modified it more?

I thought i would be able to reach over 50 knots 2up? And what would be necessary in that case to make more power and gain more speed?

 

[roflhat]

I think your speed is ok for a standard engine. When you are 2up try and keep all the weight as far back in the boat as you can and play with the trim to get it just right. Worth skimming the head, you can take 1mm off the standard head gives 30psi more compression and more power

 

[Aron50tohatsu]

Okay! Will take 1mm off and maybe blueprint it! And is it safe to not have the overrev safety or is it necessary to weld the crank??

 

[roflhat]

I would weld the crank before you cut the limiter, the crank is pressed together and if the press lets go then you have big problems

 

[Aron50tohatsu]

Okay thanks alot!

 

[Cornishpowerboater]

I got 58mph 2 up out of my 50 on a ceasar f11 with very minimal mods boyesen reeds, welded crank, and some velocity stacks with a forge marine v2 18 pitch
luckily your talking to the right guy as roflhat is the guy behind forge marine
my engine was about 25-30 mm up from bottom of hijacker valves and was running 2nd trim pin up with a fastcats trim pin spacer so basically adds another half a hole of trim