Carb cleaning fluid sprayed

[divimon2000]

Hi all, I have a 90 HP Loop Johnson 1999 and have cleaned the carbs but.... I also tried some addtional carb cleaner in the throats at idle and this is what happened: spraying in 3 cylinders caused the engine to decrease in idle speed while one (top right) INCREASED the engine idle and created some blue smoke as I sprayed. Too rich mixture in that carb? I have a manual and the VRO is disconnected. Thanks.

 

[countvlad]

Re: Carb cleaning fluid sprayed

Hi all, I have a 90 HP Loop Johnson 1999 and have cleaned the carbs but.... I also tried some addtional carb cleaner in the throats at idle and this is what happened: spraying in 3 cylinders caused the engine to decrease in idle speed while one (top right) INCREASED the engine idle and created some blue smoke as I sprayed. Too rich mixture in that carb? I have a manual and the VRO is disconnected. Thanks.

spraying in the throats is not going do anything other than clean the butterfly, intake manifold, possible reed valves and maybe cylinders...

follow the link below how to properly decarb an engine....


why the rpms increase cant tell you.. what i would do is a compression check on all cylinders get an idea ...

what are your idle and WOT rpms??? why the spraying in the carb throats???

and BTW i would never spray any carb cleaner in the motor...

 

[divimon2000]

Re: Carb cleaning fluid sprayed

Appreciate the feedback. Yes, the compression is great. WOT is 5,200, idle is a bit high after the sync and link (maybe 1,200, was 800 before)

I was spraying carb cleaner just as a final clean job. Been working on locating a very slight rpm drop at high rpm only. Intermittent. Have a feeling this symptom leads to the culprit. Cleaned all 4 carbs, Did a de-carbonization as well. Also checked all the fuel lines, filters, valves, etc so will move on to spark if this carb thing doesn't pan out. Oh yeah, sync'd and linked too.

 

[bankerjohn]

Re: Carb cleaning fluid sprayed

You should never spray carb cleaner down the throat of a carb on a outboard motor while it's running (or when trying to start it) ... it will "clean" the oil off the cylinder walls, and potentially damage the engine.

Put some pre-mixed fuel in a spray bottle instead!

 

[tashasdaddy]

Re: Carb cleaning fluid sprayed

agree 100% with bankerjohn.

 

[Sea18Horse]

Re: Carb cleaning fluid sprayed

If you add extra fuel (carb cleaner in this case) and it slows down then that means the mixture is either just right or already too rich. There are a couple of ways you can tell which it is but that's not important just now.

If you add extra fuel and it speeds up that tells you it's too lean. Either because of an internal carb problem or a vacuum leak. Generally if it speeds up above your normal idle speed suspect a vacuum leak. If it speeds up to around your normal idle speed suspect an internal carb problem.

You can do the same tests on the water at speed but you'll need a driver. And as a source of extra fuel you should use a spray bottle filled with premix as opposed to carb spray.

I'm guessing one of the jets in the offending carb is not as clean as it could be. Good luck!

Cheers................Todd

 

[divimon2000]

Re: Carb cleaning fluid sprayed

Todd, great thoughtful answer. I'm on it. Will post results shortly. And I won't use carb cleaner anymore:redface:

 

[vegasphotoman]

Re: Carb cleaning fluid sprayed

I agree with Todd

and awsome job on your gt150 BANG UP JOB sweet boat! nice work!
checked out the cool vids and pics on your utube, real cool!
posting all those pics and vids sure makes boat resto information alot more fun for the rest of us