Running Rough 90HP 1985 PLEASE HELP

[mick3446]

Before I take my boat to the shop I am hoping you guys could help me out. I have 90HP Johnson 1985 J90TLCOS model. The motor runs and I took it out yesterday?it idles rough and will stall out if I let it idle for any length of time. When I put the throttle down it jumps right out of the water and really moves but once up to top speed it will start to break up and then stall out unless I pull back on it. It will cruise at mid throttle with no problems but once I slow down it will break up again and sometime stall. I also noticed when I trim the motor up it begins to stall. Any help or ideas on what I can do to save a few bucks prior to being at the mercy of the boat shop.

 

[Big Bubba]

Re: Running Rough 90HP 1985 PLEASE HELP

When is the last time the carbs have been cleaned out? What about your fule is it fresh and clean? Bob

 

[mick3446]

Re: Running Rough 90HP 1985 PLEASE HELP

New carb kits and fresh fuel prior to taking out... maybe i didn't set the floats right? But would that cause it to break up?

 

[Big Bubba]

Re: Running Rough 90HP 1985 PLEASE HELP

If you didn't set the carb floats up right and your not too sure you did set them right I would double check that becuase that would cause an issue as you described. How did you set it if you think that was done? With the carb upside the float should be parallel with the carb body and you should not be able to blow through the fuel inlet line and if that is good then when you turn it right side up you should be able to blow through the fuel inlet just fine. Also make sure you blow out all your jets and did you soak the carb minus all the rubber and plastic parts in carb cleaner? Let us know, Bob

 

[mick3446]

Re: Running Rough 90HP 1985 PLEASE HELP

I put the floats in just as they came from the kit...also I did not soak the carbs at all I sprayed them out with carb cleaner but never soaked them. It looks like I'm rebuilding carbs again. Thanks for your help. What should I soak the carbs in?

 

[Big Bubba]

Re: Running Rough 90HP 1985 PLEASE HELP

Yes, sounds to me after reading your last thread entry that your jets might be still clogged up and have some varnish on them. What I did is bought a gallon size paint can of Gunk parts and carburetor with the parts basket inside of it from Advance Auto Parts or you can buy this at any Auto Parts store of your choice and then let them soak for about 24 hours. Please make sure you remove all the rubber and plastic parts from your carb becuase the carb cleaner will eat them up, just soak the metal parts only. Then when they are done soaking I have an air compressor that I used to blow every single orifice that I could find and also run fine extension cord strands of 3 o4 wires through those orifices and then blow out each jet another time with the air compressor and then put everything back together again and you should be good to go. Take care, Bob

 

[jonesg]

Re: Running Rough 90HP 1985 PLEASE HELP

Try watching this video.
Run wire through carb jets to clear them.

http://www.youtube.com/watch?v=o5cxBMDezuU

 

[mick3446]

Re: Running Rough 90HP 1985 PLEASE HELP

Big Bubba,
Thanks a bunch I will do as you said and let you know how things turned out.

 

[Big Bubba]

Re: Running Rough 90HP 1985 PLEASE HELP

I really think that going through those carbs again will solve your issue and your outboard will run right. When you do this again see if you see anything that might be clogged up like those jets. I will periodically check this thread and see if you have any luck doing these carbs again. Take care, Bob

 

[mick3446]

Re: Running Rough 90HP 1985 PLEASE HELP

Well I soaked the carbs for a little over 24 hours in carb cleaner gallon can with basket. Used the compressor to blow out the jets that carb cleaner did a great job. I measured the floats and they were correct...now here is the sad part I took the boat out and it is doing the same thing breaking up at full speed and even when going slower. Do you think it could be the old VRO that is now used with premix? I'm just lost trying to figure this motor out. New plugs, new wires on correctly, new fuel filter. Any help would be great

 

[ondarvr]

Re: Running Rough 90HP 1985 PLEASE HELP

If you have sudden intermittent missing at high speed, check the coils and/or the rest of the electrical system. If it dies out gradually then check for a bad fuel pump or leaking (sucking air) fuel line.

Were the VRO lines plugged correctly when it was disconnected?

The high and low speed issues may, or may not be related.