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Johnson GT 100 Model J100STLCCA - Hard to start

DPW

New member
I have a 1988 Johnso GT 100 that sat abandoned for many years - older engine but not many hours on it.

I took it to a marina that had some old timers working there and they shockingly got it started right away. (cool guys and I wish I could have hung around with them to get some experience), They replaced the electric choke and did a water test. So far so good.

I took the boat to NH and once there it was really hard to start. Once started it runs very well (other than being a big gas guzzler). I added Serafoam engine treatment to the first few tanks of gas and used high test fuel - the more I used it the better it was. BUT at times it is very hard to start - sometimes it starts right up - most5y not. I pump the fuel bulb - push the key in to activate the choke and crank. Eventually I stop choking and then simply let it crank a LONG time and then it slowly starts showing signs of life - a little smoke, a little sputter and eventually it starts and then I give it a bit of throttle and it runs and then settles into a nice idle. It seems like a fuel supply to me but that is a guess. I'm 67 and as a kid liked working on mini bikes and then cars (I'm by no means a mechanic). My son is 30 and never worked on engines. I can get it running but he cannot when I'm not there. I need to figure out how to get this motor to start easily and reliably so he can use it. I ordered a new fuel pump but that is a shot in the dark and has not arrived yet.

Any suggestions would be great .

Thanks
DPW
 
Good to Know.

I believe I might have found the problem yesterday.
(Unfortunately I only get to where the boat is sporadically)
I took the cover off the carburetors and found blow back and fuel coming out of the lower carb. (left barrel) when it was running.
After researching and talking to a mechanic it might be the reed valve.
Any thoughts?
And does anyone have an opinion on whether to replace with OEM or Boyesen carbon reed?
 
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