2003 150 Johnson how to set carb float height correctly

[2003Angler204]

I have a 2003 Johnson 150 2 stroke (j150pxstm) and have just rebuilt the carbs for the first time. One of the six was leaking gas out of the air intake and spitting gas out of the brass relief valve on the top of the carb. Is their an exact height the the bottom of the float valve should be above the carb body when setting the height, held upside down. I asked my mechanic and he said it needed to be set with a "float gauge" and I should have a professional mechanic do it. Any thoughts would be helpful, thanks. - Chris

 

[jakedaawg]

Level. I believe if you are replacing the float that the tang is plastic and therefore set. If a metal tang then usually they are good to go right out of the kit. WHat relief valve do you speak of? There are a couple of bleeds facing you when you look at the front, one of those? These would be forward facing. Have you removed and cleaned the throttle body assemblies as well as the carbs?

Welcome to Iboats! A manual, and questions answered are the best way to take advantage of the knowledgeable folks here. There are quite a few that can help you but you will need to help them help you.

Good luck, all these issues are solvable.

 

[Chris1956]

Om my '98 Johnny 150HPV6, the float height is set with the carb body inverted. The float should be parallel to the carb body.

Of course, a service manual for your very motor would be very helpful to you.

 

[Faztbullet]

Also no gasket under the inlet and needle clip is facing correct direction....

 

[2003Angler204]

Thanks for the responses. I got the seloc online manual. The carb specs says their is no guage, 11/31 - 1 1/18in or 17-28mm,AND parellel. I adjusted to these specs and the gas overflow stopped. It was the relief valve on the top left when looking at the carb. It's still running a bit rough but at least there is no gas spitting out. It still does cut out while running at high rpms, not at idle, I noticed some seapage from the float bowls, they are warped. Would that be enough to cause it to cut out at 3800rpm. Thanks for the comments. It's been a great engine for the 2 years I've owned it and now it just needs some tlc and tuning.
I removed the gasket under the inlet as that wasn't allowing the needs to set correctly.

 

[SweetD]

I had to replace all four of my float bowls when I rebuilt my carbs a few years ago. They were leaking pretty badly. It was well worth it. Never cut out at higher RPMs though.

 

[Chris1956]

I just replaced all 6 of my float bowls. Boat has been run on flusher only so far. At least it still runs, and doesn't leak from every carb bowl.

 

[jakedaawg]

Thanks for the responses. I got the seloc online manual. The carb specs says their is no guage, 11/31 - 1 1/18in or 17-28mm,AND parellel. I adjusted to these specs and the gas overflow stopped. It was the relief valve on the top left when looking at the carb. It's still running a bit rough but at least there is no gas spitting out. It still does cut out while running at high rpms, not at idle, I noticed some seapage from the float bowls, they are warped. Would that be enough to cause it to cut out at 3800rpm. Thanks for the comments. It's been a great engine for the 2 years I've owned it and now it just needs some tlc and tuning.
I removed the gasket under the inlet as that wasn't allowing the needs to set correctly.

Explain the cut out please. Does it quit? Is it just a single miss? Does it feel sudden and extreme like loss of spark or more gradual weakening like like of fuel or air?

Were throttle bodies removed and cleaned?

I doubt seloc manual has link and synch but if you were careful you should not need to.

 

[2003Angler204]

I had to replace all four of my float bowls when I rebuilt my carbs a few years ago. They were leaking pretty badly. It was well worth it. Never cut out at higher RPMs though.

I just replaced the Optical Ignition Sensor and that seems to have solved the problem of it cutting out at high rpm's

 

[2003Angler204]

Explain the cut out please. Does it quit? Is it just a single miss? Does it feel sudden and extreme like loss of spark or more gradual weakening like like of fuel or air?

Were throttle bodies removed and cleaned?

I doubt seloc manual has link and synch but if you were careful you should not need to.

The cut out was sudden loss of fire to the whole engine, it felt like some type of safety shut off. When I explained it to a mechanic he suggested that it was the optical ingnition sensor. I didn't do anything with the throttle bodies. It is still running rough and not getting up to full rpm's. It actually sounds pretty good idling but when you give it gas it sputters and then 'catches' and gets up to about 4000. When it was running great it would get up to 5000. Now at just under 4000 you can feel that its not getting full power or up to optimal rpm's.

I'm about to order all new float bowls and gaskets. When I pump the primer bulb it will stay hard for less than a minute, I'm assuming their is an air leak or several.

 

[2003Angler204]

Ok, so I for the purpose of this thread. The correct float height made the difference is running. The short answer is parallel with the carb body when inverted. The second part of it cutting out is a separate issue, yet to be resolved. Thought it was but it did it again over the weekend, several times.