Johnson V4

[WillardIII]

I recently purchased a Starcraft 15' fiberglass boat with a Johnson V4 90hp engine. The year is 1985. The engine runs well, but does not idle after I start it with the fast idle (I think correct nomenclature) shut down. For example when I am about to put into gear. I found two carburator adjustment screws (black) at bottom of engine, but the slow idle adjustment screw only allows for about a 1/10 of a full rotation adjustment. Is there something else I should be adjusting? Sorry for my lack of boating saavy in describing the problem.

 

[mikeyzx2]

Re: Johnson V4

get a service manual for it (the OEM one, not Seloc, Clymer) for one do you know anything about it as far as recent maintanence? the typical starting point is the carbs, since they like to foul up from non-use and improper winterizing. don't go a fooling with any adjustment screws until you got the book cuz they're not like fine tuning your Briggs and Strattons. your likely issue is the idle jets are dirty so make darn sure the carbs are overhauled correctly before you set the idle on it, and set the idle in the water, not on dry land with the muffs on it. <br /><br />and welcome to iboats....

 

[OBJ]

Re: Johnson V4

Hey Willard...<br /><br />Don't recall any carb adjustment screw on an 85'. Could you eleaborate a little on the location of these "black screws"?<br /><br />Idle or lack of, can be caused by serveral different items, control cable misadjustment, sync and link out of wack, carbs need cleaning and overhaul, carb linkage out of adjustment....and of course it could be just the idle screw needs set up a bit but without knowing what the rpms are at idle or what the maint record is on the engine, it's hard to say.<br /><br />Mikey is correct, if you are unfamiliar with the workings of an outboard and like to "do-it-yerself", get the manual. The OEM's are preffered cause they give you specific info on your particular engine.