1967 Johnson 100HP - carb leaking gas

[jon705]

Re: 1967 Johnson 100HP - carb leaking gas

and see what you get ,,,rs up open,,upd closed.if you havent replaced the needle and seats together,could be a prob.if you have clean fuel lines and good fuel,using the right mixture,there shouldnt really be any gumming up.check that float and needle valve/seats.dont give up youre almost there.

I replaced all four needle and seat sets at one time with a matched (gently used) set. She started up and idled again last Friday after taking the carb completely apart and cleaning throughly with carb solution and compressed air.

One thing I noticed (not carb related) is the throttle control has to be pushed quite far forward for 'er to start up and idle. Maybe after she warms up I can throttle back some. I haven't let 'er run very long in the driveway though because I don't have a barrel. Just enough to see if it makes sense to haul everything down to the dock for a tune up. Gonna try to head there this week so I'll report back.

How many turns out do you have your adj idle needles? 1-1/2 turns from gently seated approx?

working on these old motors are just part of their constant joy they give us,even though the premix,motor,barrel, sometimes look like the only thing missing there is a match.

I love your analogy!

 

[glassmaster68]

Re: 1967 Johnson 100HP - carb leaking gas

yeah 1,1/2 turns out from gently seated,,,check out those top secret files on adjusting high and low speed needle valves ,if you havent already,,,,,,,,,,,,,,,dont want it too lean ,it would scald your cyl,piston ,rings,maybe just burn a hole in a piston,and too rich fouls your plugs,,,of course rather be too rich,,,,,,,,,when its set right,it will be smooth running,,with good fire,comp,link/sync,,,,,,,,,,you will definitely be able to tell more about it when youre able to run it long enough to get it good and warmed up

 

[jon705]

Re: 1967 Johnson 100HP - carb leaking gas

I have to claim partial success. My wife and I took our boat out yesterday for the first time. I must say I'm now hooked to boating! Even though she didn't run great it was still a load of fun! We puttered around our local small lake. I can't wait to get 'er tuned up and out on the water again.

Which leads me to the next point. Those darn float needle and seats leaked again. I had a steady stream of gas flowing out the float bowl relief line and when I throttled up the engine shuttered and wouldn't make it up to speed. Should I just keep tearing apart and cleaning the float bowls each time this happens until it goes away?

 

[Al-53]

Re: 1967 Johnson 100HP - carb leaking gas

Did you change all the fuel lines on the engine....if not I would...you may be getting contaminants from the old lines on the seats...

Al

 

[jon705]

Re: 1967 Johnson 100HP - carb leaking gas

Did you change all the fuel lines on the engine....if not I would...you may be getting contaminants from the old lines on the seats...

Al

I changed them but one was the wrong size so I had to switch back to the old one...I'm getting a new (correct size) line tonight, will clean the floats again, see if that doesn't fix the issue. Thanks for reminding me!