1997 johnson 90hp stall at idle and hard start

[Joetomass]

Hi. Everyone. Having a major idling problem I really need some help with. Basically hard start, mainly cold but sometimes warm, stalls at idle, almost all the time. And sometimes when switching gears a real pain when tring to dock. I have had the motor for 4 years now and basically had the same problems all along. Cruising is ok wot is 5500. Was told that is good.
Here is what I have done
Set all carb linkages many times, Plugs, wires, power pack, stator, and all that goes with it. Sorry don't remember all there parts they put in that work with stator.compression 125-130 on all 4 cylinders, spark is strong 3/8 on all, new primer bulb, pumping doesn't help, new choke primer, New thermostats 2 sets in 2 year had carbs done 4 years ago when bought it, was told last year that they where clean and needed nothing. ( and nothin was done with them) I had the dealer set timing at end on last season, so didn't get to much time running. But they also told me they set it on muffs, thought need to be in the water or test tank?? True? False? I'm lost? I am going down this weekend to try and resolve this once and for all, before the holiday. I did forget to mention it runs better on muffs then in the water. So I was going to run in a test tank this weekend to try and resolve problem and do any repairs.
Thanks in advance

 

[boobie]

Re: 1997 johnson 90hp stall at idle and hard start

Do a cylinder drop test on it and see if you can find a cylinder that isn't firing.

 

[Bosunsmate]

Re: 1997 johnson 90hp stall at idle and hard start

Not sure how they knew carb were clean without going through them.
Id take along what you need to do them in case thats required.
Seems possible to me

 

[Joetomass]

Re: 1997 johnson 90hp stall at idle and hard start

Yes I did a drop test last year, I plan on doing it again this weekend. I'm also going to rebuild the carbs, and fuel pump. If they don't solve problem what should I check next?? Could reed valves cause this?

 

[Bosunsmate]

Re: 1997 johnson 90hp stall at idle and hard start

Yes I did a drop test last year, I plan on doing it again this weekend. I'm also going to rebuild the carbs, and fuel pump. If they don't solve problem what should I check next?? Could reed valves cause this?

yes reed problems cause bad idling

 

[Joetomass]

Re: 1997 johnson 90hp stall at idle and hard start

Is there a good way to check them? Or do I have to pull them out?

 

[Bosunsmate]

Re: 1997 johnson 90hp stall at idle and hard start

Is there a good way to check them? Or do I have to pull them out?

Ive never seen them on that engine, but often you can see them through the carbs or you have to pull the carb off and have a look.


If you put a bit of paper in front of the carbs you should notice it gets constantly sucked in it shouldnt get blown out at all.
Hold on to the bit of paper tight.