Tohatsu 9.8 Stiff Throttle

[Jasierock]

Hi All

Though I've been boating for most of my life, this is the first time I have had an outboard with a tiller operated throttle (apart from an old Seagull in the 70's)

The motor I have is a Tohatsu 9.8 2 stroke. It runs like a dream but after the winter the throttle seems stiff. I have taken out and cleaned the rod and slackened off the pinch nut fully but I still have to return the throttle to idle by hand. There doesnt appear to be a return spring anywhere on the mechanism. Is this as it should be or does something need cleaning and oiling? TIA

[TmMorris]

Not a guru but in my mind if I've greased the tiller mechanism and it all seems clean and straight then I would start to consider looking at the mechanism on the engine to see if that has the issue?

I think I'm right in saying that with some outboards all the spring return on the arm is supplied by the throttle on the engine? Maybe this is how they all work but could it be that this has become gummed up, spring disconnected or that something is causing it to not spring back with enough force to operate the tiller?

I'm guessing here and I'm sure someone with specific knowledge will post.

[Jasierock]

Thanks Tim.
The trouble is, I cant remember what it was like last year before I put it into hibernation!

[Fenlander]

To go through this you've done step one cleaning the rod and friction device. Next take off the rubber twistgrip cleaning off any corrosion, dust, debris from both tiller shaft and inside twist rubber. Waterproof grease and replace. Check cables from tiller to spindle adj carb are not displaced or badly routed. Pop off link to flywheel advance/retard and check that is moving smoothly... any difference in throttle feel with it disconnected? Next slacken off the cable adjuster nuts at the bottom of the spindle a little and see if this eases the feel. Final long shot is to remove tiller to spindle cables and lubricate.

The 9.8 I bought recently had just the same problem and mine was caused by the cables onto the bottom of the spindle being too tight... about a turn slackened on each adjuster nut sorted it. There is no return spring and I'm looking at fitting one as I like a throttle that gently returns.

[Jasierock]

Thanks Fen. I will go through that step by step and see if it improves. I too will look at fitting a return spring as the rod can be pinched with the nut if required.

[Jasierock]

Turns out its the flywheel advance/retard unit thats skicky. I have given it a spray and its a lot better but I need to look to see how easy it is to strip and clean it properly.

[Tel1965]

I’m glad someone asked this question. Mine too is a little stiff, I just thought it was because it’s new and needs a bit of a work out.

[Fenlander]

Terry I'd still go through the checks, greasing under the twistgrip and as in my case checking the to/fro wires aren't so tight its causing the spindle to bind adj the carb. Mine isn't anything like the silky smooth of my previous Yamaha but loads better.

[Tel1965]

David, I will have a look when I get around to it, but to be honest I wouldn’t have a clue what I was looking for. But, I think what I’ll do is see if there’s a video on YouTube that explains it all. I know you could explain everything to me but it’s much easier for me to learn by watching with something like that.

[Fenlander]

I don't have a Youtube account that I can access just a really old one I've lost the email for but I ought to get one really.

[Tel1965]

I’ve just had a quick look and there are some videos about the tohatsu, so when I get a chance I’ll take a look at them and try and learn a few more things. My mind is still spinning from all the things I’ve been learning over the last couple of days. When I’ve sorted the boat, I’ll sort the engine and no doubt I’ll have plenty more questions to ask lol.

[Fenlander]

I'm not sure you'll see any videos on the specific of the tight throttle so...

First remove the grubscrew at the front underside of the throttle grip and clean friction surface if reqd reassembling with waterproof grease.

Then check the throttle cables from tiller to the black plastic vertical spindle are routed as smoothly as possible.

[Fenlander]

Next pop off the black end of the link from top of spindle to advance/retard plate under the flywheel and check AR mechanism moves fairly freely.

[Fenlander]

Finally back off the brass nuts/nipples so the cables aren't pulling so tightly on the black spindle. This was the problem on mine... they were so tight as to cause the spindle to bind as it tried to rotate.

[GAVMAC321]

Should the twist grip spring back if you let it go ?

[Fenlander]

No it has no return spring. But I will look at fitting a mild one.

[GAVMAC321]

I've recently bought my first outboard and i was surprised there was no return for the throttle. I had a look at the linkage and it'll be relatively straight forward to fit in my Tohatsu 8hp ��

[Fenlander]

Is your 8 a 4-stroke... if a 2-stroke it would be the same layout as mine and I'd be interested to know where you reckon a spring would best go.

[GAVMAC321]

My one is 4 stroke

[Fenlander]

Ahh OK.