Soup my 30hp Tohatsu!

[A1C_Bartosh_843]

Hey y’all, I’m new to this forum..if you couldn’t tell. Hell, I’m new to forums period. I’ve always read others forums but never posted, never made an account. Mostly because I never sought the need to. But back to the point. I have a 1548 g3 jonboat that I love dearly. I love sliding around the river, I love runoff racing, anything a redneck could do in a boat I’ve either accomplished or have it marked on my list. I currently work for Freeman Boatworks here in Summerville SC and have been in the boating industry for a while. I used to have a 1978 35 hp long shaft evinrude firepower on the back of my Jonny to start. Dads first bought motor back in the 70s so he past it down to me. It planned out right away and made my boat a river jet. The hole shot power and reliability was insane...just of August last year I sucked it up and got a 4stroke 30hp Tohatsu short shaft in hopes my speed/reliability wouldn’t be sacrificed but would gain mileage out of the non ethenol gas I’ve been getting. But honestly, I’ve lost power. I feel as if I lost speed. Running those run offs with a buddy up front leaning into turns and cutting angles just doesn’t feel the same. I want to boost my motor. Is there any way possible? I have ordered a dunk boost chip kit for my motor but haven’t recieved it yet. Y’all please give me some insight on the possibilities of getting more out of this motor

 

[roscoe]

First things first, Welcome to iboats.

Your post brings several questions to mind.

Your original motor was a long shaft, your new motor is a short shaft.
Which one is correct for your boat?
How tall is your transom?

Where is the anti-ventilation plate of the motor, in relation to the bottom of the hull?
See diagram below,.
Bottom red line in diagram should be even with, or slightly above the bottom of your hull.



What was the pitch of the prop on your old motor?
What is the pitch of the prop on your new motor?

Was the old motor propped correctly, operating within the recommended rpm for your motor?

What about the new motor?

You will need a tach to optimize performance.
A smal inductive tach will work.
Something like a "TinyTach", or similar.

Do the lower unit gear cases have the same gear ratio?


And you thought this was gonna be easy.

 

[Sea Rider]

Yep as stated by Roscoe, too many importamt points to bypass. Don't install or add anything to that erngine prior having checked all points. Hope you don't have to chop transom down or buy a long shaft lower leg to match your transom height if being Long.

Happy Boating

 

[A1C_Bartosh_843]

I will give y’all the specs tomorrow to give you both a more thorough explanation as to what I’m dealing with. Thanks for the welcome! I honestly thought I was going to get pushed aside which is why I’ve never posted on forums before lol

 

[roscoe]

Sounds good.
The more info you can give us, the better we can help.

 

[Scott Danforth]

I will give y’all the specs tomorrow to give you both a more thorough explanation as to what I’m dealing with. Thanks for the welcome! I honestly thought I was going to get pushed aside which is why I’ve never posted on forums before lol

this isnt facetube, we actually like to help people

 

[roffey]

pictures are best, even if it has nothing to do with the problem, lol. I think they call it boat porn, bahahaha.

 

[Stumpalump]

The old resistor on the air inlet temperature sensor trick?
http://www.magnumtuning.com/en/detail/dyno-boost-boat-performance-chip/tohatsu/30-efi

 

[b.gagnon]

The 30hp Tohatsu is a great motor but has no power compared to a 2 Stroke! A friend of mine had a (properly setup)13' Classic Whaler with the same motor and it would struggle to get on plane with 2 adults.... Top end was great once you got it spinning but low end power was lacking.. I have the same boat with a 35hp Johnson and I barely have to hit the throttle to get on plane with 2 adults! If your setup is correct then I would suggest you find an older 2-Stroke motor or an E-tec to play with! The Tohatsu could run all day on 6gal of gas in that boat, and you could barely tell it was running at idle.

 

[Sea Rider]

If you haven't tached OB as loaded won't know if OB revs inside middle to max wot rpm range, going for less pitch props cures slow hole shot. All OB's factory delivered usually comes with medium pitched props and most of the time not suited for your load and application.

Happy Boating