Tiller steer question

[Tailhook]

I have recently bought an aluminum boat with a 9.9 Johnson ...1999 model. This is my first experience with an engine this small. What exactly is the function of the adjustable knob at the end of the throttle twist grip. I'm guessing something to do with idle speed but mine seems to do nothing regardless of how I set it. What's the fix for it..replace the entire twist grip assembly ? Thanks

 

[flyingscott]

It is a throttle lock for trolling. It allows you to lock the throttle in place to hold a specific speed. They are usually broken because people do not know what they do.

 

[Vic.S]

I have recently bought an aluminum boat with a 9.9 Johnson ...1999 model. This is my first experience with an engine this small. What exactly is the function of the adjustable knob at the end of the throttle twist grip. I'm guessing something to do with idle speed but mine seems to do nothing regardless of how I set it. What's the fix for it..replace the entire twist grip assembly ? Thanks

#6 in the diagram below ?

It is in fact the idle speed adjustment, Your owners manual will tell you this. Some people, however, seem use it as a trolling speed setting knob. or at least seem to think that is what it is. for
From the parts list:

6

0584302

ADJUSTMENT, Idle

Turning clockwise increases the speed, but you have to open the throttle a little first because it acts as a stop to limit the movement of the twist grip. Counterclockwise decreases. the idle speed setting by allowing you to then turn the twist grip to a lower setting.
It is quite a fine adjustment, needing a quite a bit of twiddling to make much difference to the speed.

Some engines have a clamp on the twist grip that enables you to lock the throttle setting for trolling or cruising , but not this one

 

[racerone]

A new ---entire twist grip assembly ----Would set you back big $$

 

[flyingscott]

My owners manual says it.is a throttle lock.

 

[Vic.S]

A new ---entire twist grip assembly ----Would set you back big $$

But the idle adjustment assembly is available separately for around $25 to $30 .

My guess though is there may not be anything wrong with it , Just a question of figuring out how it works

 

[Tailhook]

Sorry for the delayed response. ...death of a close friend has rattled me today. Thanks guys for the good info, I will tinker with it a bit more to see if I can figure it out. I don't have an owners manual. So if it is in fact defective. ..which item numbers from the parts list would I need to replace?

 

[iggyw1]

Sorry for the delayed response. ...death of a close friend has rattled me today. Thanks guys for the good info, I will tinker with it a bit more to see if I can figure it out. I don't have an owners manual. So if it is in fact defective. ..which item numbers from the parts list would I need to replace?

Wow, that would be a tough question for anyone to answer. It would all depend on what parts are disconnected and/or broken. My guess is that you just need to adjust it. It is probably unscrewed way too far. TRY THIS: Set the idle speed up a little high with the twist grip on the steering handle. Now turn the knob at the end of the handle clockwise all the way in until it will not turn any more. (If it does not stop turning in a clockwise direction, it needs repairs). Now try to lower your idle RPMs using the twist grip on the handle. It should not move. If you want to move it to get less RPMs, turn the knob a little counter clockwise and the twist grip should move to go slower. If this does not work, it needs repairs.

 

[Tailhook]

I'll give that a try...makes sense. ..had no idea how it's supposed to work . Thanks