1975 johnson 6 carb rebuild

[gnarbrah]

Hello all,
So my last post was about the motor "sputtering" (if you search my username you can see the video). Anyway, I bought a carb rebuild kit that is complete with a bunch of rubber washers, gaskets and all that jazz. I'm sure there's a post on here talking about this but I didn't find one yet, point is when I removed the carb, the nut near the recoil rope was (at best) finger tight. Am I correct in thinking that it could have been sucking in air causing the sputter at high throttle?

Since I have it out I figure a rebuild isn't a bad idea, so I pull the bowl off and it looks brand new in every crevice and through every hole I can look through including the high speed valve (I'm assuming thats what that is that goes up through the float?). Speaking of the float, the one in there appears to be cork and the new one is rubber is this normal?

What steps do I take? The kit looks like it comes with all kinds of stuff including replacement plugs, they look like freeze plugs. Do those need to be replaced and how would that be done? Lastly I've read alot about a "decarb" what exactly does that mean?

Thank for all your help!

 

[OLDIRON]

Re: 1975 johnson 6 carb rebuild

Hi,I'm new to this too,but I can offer you this much.When I just rebuilt my 75 15hp,I did not punch the welsh plugs out,eventhough they came with the kit.A good soak in carb cleaner for a few hours,and compressed air,did the trick for me.I guess some go as far as removing the lead shot plugs,but I wasn't about to do that.For one thing they are not in the kit,and are beyond my experience. From how you describe the condition of the bowl, it sounds like the carb isn't too fouled.Loose nut causing air leak? Maybe,but I doubt it.There is a gasket there,and what I have found,even when I took both nuts off,it still took a pretty good pull to brake the seal of the gasket.I don't think too much air could have gotten by that. I think with a good carb cleaning your sputtering may be a thing of the past. Hope this helps,and good luck.

 

[F_R]

Re: 1975 johnson 6 carb rebuild

The nut could have been a problem. Unbolt the recoil and tilt it to one side to get access to the nuts. No need to disassemble the recoil as long as you only lift it enough to be able to tilt it.

How about the high speed orfice jet? It is deep in the hole behind the hex drain plug in the carb bowl.

The term "sputtering" indicates an ignition problem rather than a fuel problem, if that is an accurate description.

 

[gnarbrah]

Re: 1975 johnson 6 carb rebuild

Thanks for the input -

I took the 5 screws out that attach the bowl to the upper end of the carb but there doesn't seem to be anything in it at all, just a bowl. I have the exploded diagram from OMC's website so I can find most everything but I'm just trying to see where any clogs may be. There doesn't seem to be alot to this carb. I'll post some pics tonight of what I've got.

I was concerned that it might be an ignition issue but it seems somewhat sporadic. When I take it out cold it runs great for 30 minutes to an hour then the sputtering begins. I talked to the guy at the parts place and he said do the carb first and see if it clears up then worry about the ignition. He said I need a flywheel puller and all that, I'm pretty handy but is this getting in over my head?

Thanks

 

[67Johnson6HP]

Re: 1975 johnson 6 carb rebuild

Sounds like it could be a coil breaking down. See how it goes with the carb rebuild and if you still have problems pull the flywheel and check the coils. I don't believe you'll be in over your head if you get an OEM service manual. Of course you will have to aquire some tools to do the job but they will always come in handy somewhere down the road.