1998 Johnson 90hp 60 degree RUNAWAY IDLE

[jayp0629]

the motor starts up fine.. after a minute of running the idle starts to climb and climb and climb... itll go easy 3k.. itll slow down if i choke it..only for a second.. then start running away again. when its IN GEAR it idles fine...maybe a hair too fast (1000+/- 100) as soon as i put it in netural it will race away again. its got a brand new optical ignition, new fuel lines, new water seperator and new plugs.. i can video this if needed.

 

[tx1961whaler]

Re: 1998 Johnson 90hp 60 degree RUNAWAY IDLE

Did this happen before the new fuel lines and water separator?

 

[jayp0629]

Re: 1998 Johnson 90hp 60 degree RUNAWAY IDLE

yes its been going on for a couple years.... dealer who had the warranty insisted it was fine and would not touch it. its never broke down on the water but it seems to be getting worse... now i cant sit in netural anymore without constant chokeing till it almost dies .. then race back up a few seconds later.. choke again.. ect.. and when i go from foward to reverse to dock itll slam into gear cause it wants to idle up right away.. in gear its perfect..

 

[Faztbullet]

Re: 1998 Johnson 90hp 60 degree RUNAWAY IDLE

Check the linkage between the carbs as it sound if sync and link is not adjusted properly. Only a couple of things will cause this: (1) carb linkage misadjusted (2) possible vapor seperator flooding thru vapor pump (3) Quickstart feature is not working properly(faulty pack or t-stats) (4) sensor cam on top of flywheel binding and timing is held advanced