Tohatsu Remote Control Throttle design/ adjustment/ wear/ maintenance ?

I have a 1991 M30A3 with remote throttle and the remote control lever will take and hold a full throttle
condition until the boat speeds up and gets on plane and then when I throttle back to something like
4800 or 5000 rpms for permanent cruising the rpms will bleed off slowly over the next minute down
to a speed that is below min planing speed. So what I have to do is constantly manipulate the
throttle just like the accelerator in a car floorboard to maintain a sub redline cruise speed.

I have not seen any literature about the design or construction or maintenance of the Tohatsu
remote control throttle and transmission unit but it seems like there ought to be a way to
tighten it up to hold rpms at whatever I set the lever to.

Is this possible and is there any detail descriptive workshop or repair manuals for these units ?

What is he best course of action here.

Thanks
Scott in Atlanta

Depending on the actual part number (or at least model) of the RC box, there is a throttle friction screw to do just that. If the motor was tiller-converted, and the tiller handle is still attached, you can also adjust the friction on the tiller handle.

here are photos of my control box. I called Tohatsu.com and spoke to a tech and he said that
a knob protuded out of the front of the box that could be turned for friction adjustment. My control
box does NOT have a knob but there is a plastic plug that does not look like it was intended
to be removed from the outside. I would have to drill a hole in it and insert a screw to grab it
to pull out. I wonder maybe if I should take the covers off the control box by removing several
phillips head screws instead of drilling a hole and screwing in a screw in the plastic plug?

I can understand an entire marketing and distribution network being dismantled and losing
a lot of documentation ( if something like that happened in the USA) but there is no way
the guys in Japan could lose the manuals and drawings from the older products. Does anyone
speak Japanese ?

Your control is not equipped with the throttle friction screw. You should be able to add it. You will need items 40, 41, and 42 from the picture:

Hi Paul. how are you?
I read in one of your posts about adapting a remote control box for a Tohatsu 6HP Model MFS6BS 3R4 Serial 044993XE
do you have the parts for the job?

thanks.

I have good news and bad (expensive) news.

Yes, I can supply you with what you need. Be aware that the MFS 4/5/6 does not have provision for electric start, so you would still pull-start, and then use the RC box. You need to come up with a steering method. If the boat already has tiller cables (dual vinyl-coated pull-pull cables), you will be OK; Since the MFS 4/5/6 does not have a tilt tube, a teleflex-type (push-pull) cable would need to be attached to the boat, and then a link added to connect to the motor.

Regardless, you will need two cables (for throttle and shift). They will cost about $46 each, depending on length -- you need to measure from the RC box to the motor, and add a couple of feet. You will also need an SRC kit to connect the cables to the motor. That retails for about $324. You will also need an RC box. The box that Tohatsu currently sells would cost about $328.

That's if you do it by the book.

That said, I can really help you out here. I happen to have a new obsolete (NOS - New Old Stock) Tohatsu/Nissan RC box which will work for you for $50. So, all up, you will be in for a little over $400, but I would be saving you almost $300.

Let me know.

Good mornmg Paul.
Thats greats news!
Can you email me at
[email protected]
so we can talk further?
Thanks a lot!

Hi paul, I sent you couple emails, maybe they are in your junk inbox?
I would like to buy the remote control box, since you said it will work for me. How can we proceed?
In the emails I sent you, I included my phone number so we can talk further.
thanks.