Can't get '86 90hp Johnson to idle

[snapperwhipper]

First some facts,Its a 1986 90 hp Johnson Model #JTLCDC and serial# J7138963,now my sad story....In the begining everything was good then it started to idle rough and die right at the dock when you need it the most ,so I rebuilt the carbs using a kit that didn't have floats included just gaskets and o rings.I cleaned everything including the jets and all the parts and put it back with no real improvement.I also replaced all fuel hoses,the fuel pump and all clamps,cleaned the in-line filter and replaced the water separator,new spark plugs,wires look good and metered about 800 ohms.I tested all electral componets with my fluke meter as best as I could,Then I replaced a power pack and none of this helped!! I used my shop manual to sycnchronize my timing and idle adjustment as best as I could .The thing runs great,jumps up on a plane and cruises 4200RPM and hits 5700RPM at WOT but when you slow down and pull back the throttle to neutral it idles for 10 seconds and dies .I am trying to set the idle at about 800/900RPMS and it sputters and dies every time.Do you guys think it a ignition problem or a fuel problem and do you think I should have replaced the floats?Thanks in advance and I am open to all help (MIKE)


Modified by snapperwhipper at 11:30 AM 10/2/2009

[Robsdad]

First off I confess I have no answers. I have the same exact 90HP Johnson. It is a great engine for its age. It also has the idle problem although not as bad as what yours seems to be. I have it mounted on an old 84 Cheetah Bass Boat and the controls have a lever that lifts up that you use for starting. When I am waiting at the ramp for the trailer or waiting for my son after parking I just lift that lever and the problems all go away. Mine will also get to plane real snappy and has good top end and I hope last forever. I wish I could help you with your problem just wanted you to know you are not alone with this issue. Have a great day.