new 9.8 tohatsu how do I slow the idle speed down, still have viberation

[rocket rich]

Problem 1 when coming into my dock I can't seem to go slow enough, is there a way to adjust or will it break in soon?
Problem 2 still have viberation when going about 3/4 speed , enough that you feel it through the seat ??
Problem 3 why am I having to put the motor on a higher trim setting up 3 holes?
Really a gas saving Motor. with my Old Johnson I would have used at least 4 gallon whereas with this motor only 1 1/2 gallons...
Problem 4 is there a way to move the kill switch to a different place????
there you are Have at it:grumpy::mad-new:

 

[TOHATSU GURU]

Re: new 9.8 tohatsu how do I slow the idle speed down, still have viberation

1) The only adjustment screw on the carburetor is the idle adjustment screw. Break-in has nothing to do with it. You can also change the propeller pitch to lessen speed.

2) Boat issue. Put a piece of rubber matting over the transom and then put the engine on it.

3) Depends on how the boat is loaded and if the engine is correctly installed.

4) Yes, extend the wires and mount it anywhere...But, I can't figure out why you would want to do that. The lanyard should reach any point that you could be at and still operate the engine.

 

[rocket rich]

Re: new 9.8 tohatsu how do I slow the idle speed down, still have viberation

it's too hard to turn around to kill the motor. I plan on putting the rubber when I pull the motor on my boat in the water. Get off that stuff if the engine is installed right ... I don''t want to void the warranty

 

[TOHATSU GURU]

Re: new 9.8 tohatsu how do I slow the idle speed down, still have viberation

At least 90% of small engines are not installed correctly. It has to do with the position of the cavitation plate in relation to the bottom of the hull. I spend quite a bit of time each week explaining to people that there is more to putting an engine on a transom then just centering it. Have a nice day.

 

[rocket rich]

Re: new 9.8 tohatsu how do I slow the idle speed down, still have viberation

Guru, you are correct in place the motor on the transom. There is more to it than just centering it. Each boat is different,I go by the way the boat rides in plane. If the bow is riding too high I adjust the motor to lower the bow. by raising the trim adjustment. I know of no other way to do it. if there is another way , I'm listening???? There just seems too be a lot of problems with these motor?? I don''t think it's necessary to keep fooling with a motor The factory is pretty smart most of the time.

 

[pvanv]

Re: new 9.8 tohatsu how do I slow the idle speed down, still have viberation

What is your jack height? Is the anti-ventilation plate at the right height?

 

[rocket rich]

Re: new 9.8 tohatsu how do I slow the idle speed down, still have viberation

I'm in the third from the top, as for the anti vent plate no idea??? 1542 lowe it's about 35 years old great boat no leaks and set up the way I llike it

 

[pvanv]

Re: new 9.8 tohatsu how do I slow the idle speed down, still have viberation

Not trim position, jack height. If you aren't familiar with that term, you are shooting in the dark.

The antiventilation plate should be about even with the bottom of the boat. Modern Japanese OB's actually have longer shaft lengths than the old US models of 35 years ago, so many must be mounted with the transom clamp above the top edge of the transom for proper performance. In order to confirm, you must have the boat out of the water, and check it. It's also a bit of trial end error testing, as each boat behaves a little differently. Rule of thumb is 1" above or below the bottom of the boat, depending on design.

BTW, raising trim will raise the bow... not lower it.

 

[rocket rich]

Re: new 9.8 tohatsu how do I slow the idle speed down, still have viberation

you guys are correct, We you and I don't speak the same ,But we do agree on what's required to operate correct. You say Jack height -I called it trim but the Jack height to me means how the boat rides in the water , You meaning you and I adjust the thrust rod not the trim tab. So today was a bad day, battery went dead, pull starting this little bugger was a B___h. but not all was lost, I took the boat out of the water and had a chance to look over the installtion. Vent plate even with the bottom of the boat thrust rod in the proper place for my boat. Still anyone want to buy this jewel.. PM me and we can talk. I knew I had it right way on the boat.

 

[pvanv]

Re: new 9.8 tohatsu how do I slow the idle speed down, still have viberation

No. Still not the same thing.

Jack height is how high the clamp is located on the transom, which translates into the relationship of the anti-ventilation plate to the bottom of the boat. Since this motor is about 1-3/4" longer than an old US model... Odds are you need to add a 3/4" or 1" (or more) piece of blocking to the top of the transom before mounting the motor.

Adjusting the position of the thrust rod works in conjunction with that to get a proper bow riding height. Typically, you want the motor exactly vertical (plumb) when the boat is at speed.

The small trim tab (which is also a sacrificial anode on these motors) is used to correct steering torque -- nothing more or less.

BTW, the idle speed must be set to specs, with a tachometer, if you expect normal operation. Then if you still want to go slower, install a prop with less pitch (possibly even one of the HT props used for heavy displacement hulls -- but that will limit your top speed). OR... you could set the idle so low that you can stall the motor, and then just don't normally go all the way back to idle. In that case, you can idle really slowly, and in fact can kill the motor, so you don't need to turn around to hit the kill switch or pull the stop lanyard to stop the motor. Granted, that setup would confuse the average person, but you have a non-typical need.

 

[rocket rich]

Re: new 9.8 tohatsu how do I slow the idle speed down, still have viberation

Very Good Captain. You went out of your way to help me out. Thank You. I fully understand what you said..... Keep in touch. You are a Excellent Teacher....I now know what I want to do..

 

[rocket rich]

Re: new 9.8 tohatsu how do I slow the idle speed down, still have viberation

I did add some blocking to the transom . but I don't notice any difference. motor does ride a little higher. shims do the job and rubber on the transom is a little quieter but not much . I only see on this site is clean the carb. Why all the dirt ?? Is it from the gas left in the carb at the end of the day..

 

[pvanv]

Re: new 9.8 tohatsu how do I slow the idle speed down, still have viberation

In order to verify proper jack height, you must operate the boat at speed, with correct trim (for proper bow angle) and observe the water flow at the motor. The surface of the water should be between the antiventilation plate and the splash plate... preferably close to the AV plate. You may need to raise the motor an inch or more... but only on-water testing can confirm that.

What kind of rubber pad did you use? Sometimes the best is indoor-outdoor rubber-backed carpet.

The carb cleaning issue is because of 1- poor fuel and 2- people not running the carbs dry at the end of the day.