advice on rebuilding 9 1/2 carburator

[Duane1]

Got a rebuild kit for my 68 Johnson today. any advice or special instructions to take apart and replace?

thanks
Duane

 

[samo_ott]

Re: advice on rebuilding 9 1/2 carburator

Take your time... Clean everything... soak it if you can... Some folks say to use wire to clean the orfices, but as I weld I have welding tip cleaners and they work much better than wire (unless you have to bend them) and they can be bought at most auto stores...

 

[iwombat]

Re: advice on rebuilding 9 1/2 carburator

I'm a firm believer in never putting wire through carb jets. Every service manual I have outside of outboards expressly warns against doing so. Seems to be standard practice in the outboard world for some reason though. Make your own choice on that one.

 

[Duane1]

Re: advice on rebuilding 9 1/2 carburator

Thanks!

The guy at the shop said to clean it with carb cleaner real good? Also this way be a stupid question as I never had a boat before but what about the oil drain and in plug on the bottom? Pretty much just keep it full?

Duane

 

[iwombat]

Re: advice on rebuilding 9 1/2 carburator

Edit: Guessing "oil plug in the bottom" means lower unit fill plug.

The lower unit oil you should change if you haven't already. The procedure is as follows:

Remove lower plug drain plug, then remove upper relief plug and let it drain.

Fill the LU through the lower hole until lube comes out the top hole. Insert the top relief plug, remove lube spout, insert lower plug.

Make sure to use fresh seals on the plugs _every time_. Buy a half dozen at a time and remember where you put them.


For that carb - carb cleaner and compressed air if you have it. Make sure to get all the little nooks and crannys, spray through every orifice and make sure it comes out someplace else.

 

[ezeke]

Re: advice on rebuilding 9 1/2 carburator

Put the motor in forward gear and turn the handle counterclockwise to get to the fifth bolt and remove the carburetor as a unit. The high speed jet is horizontal, just behind the drain plug on the float bowl.

 

[Duane1]

Re: advice on rebuilding 9 1/2 carburator

Thanks for all the help. Will try this weekend. I want to go fishing on Sunday!

Duane

 

[Duane1]

Re: advice on rebuilding 9 1/2 carburator

Got kit installed and it's going! Changing the gear oil now. Ok, now what? Did what I could to get it running smooth. Are there any correct procedures to tuning it or making it run the correct way? It has a mixture knob on front and another dial on the rt side that is idle mixture? Thanks for all so far!

Duane

 

[iwombat]

Re: advice on rebuilding 9 1/2 carburator

Dial on the front is the low-speed idle mixture. Dial on the side is the idle speed.

To set the mixture the first time.

Pop knob off
Turn mixture screw in until seated.
Back out 1.5 turns (I think this is right - little help??)
Start motor and let it warm up to operating temp.
Turn throttle down as almost far as you can and keep it going.

Turn screw in 1/4 turn. Let the motor settle in for about 10 seconds. The idle speed should pick up as the mixture gets closes. If the speed picks up, set the throttle to turn the speed back down in small increments. Repeat.

At some point you will turn the mixture in too far and the motor will start to sputter. Back out about 1/8 turn and leave it.

Put the knob back on with the pointer centered in the middle.



Set the idle speed adjuster to just above where the motor wants to die in gear.


Enjoy.

 

[Duane1]

Re: advice on rebuilding 9 1/2 carburator

Am I doing this in nuteral or foward, and what about the choke, as my speed varys?

 

[offshore100]

Re: advice on rebuilding 9 1/2 carburator

Some folks say to use wire to clean the orfices, but as I weld I have welding tip cleaners and they work much better than wire (unless you have to bend them) and they can be bought at most auto stores...

orifices are soft brass, tip cleaners are hardened steel, too easy to inadvertently oversize your orifice. Wire is copper, softer and not so bad, OMC/Bomby recommend toothpick.

 

[offshore100]

Re: advice on rebuilding 9 1/2 carburator

Am I doing this in nuteral or foward, and what about the choke, as my speed varys?

adjust idle while in forward gear, if you can, and for pete's sake, no choke!

 

[iwombat]

Re: advice on rebuilding 9 1/2 carburator

Everything but the idle adjust I usually do in neutral. No reason it couldn't be done in gear just not necessary.

These adjustments can be done in a bucket, but you may find yourself having to fine-adjust on the water.

 

[ttgoddard]

Re: advice on rebuilding 9 1/2 carburator

For some reason in the manual I have it states 3/4 of a turn for the 9.5 whereas 1 1/2 turns for most of the other small HP engines. I just fully cleaned all the ports and jets in my carb two nights ago and after putting it back on started at 3/4 turn for a basis. After it was warm and and in neutral I increased the idle just a little and after adjusting the low speed mixture ended up at 1/2 turn out and it runs great and idles real well.

Hope that helps.

Tony