Johnson 9.5 HP will not run w/o choke

[tkrules19]

Hello i just recently acquired a 1973 Johnson 9.5 HP outboard. Since i got it, i did all the maintenance on it because i had no idea what was done but it was a cherry motor hardly used not even a scratch. One of the things i did was rebuilt the carb and it just does not want to idle without choke (but it was doing this prior to the rebiuld). I have the original service manual for my 73 and i have just about did everything trying to solve the problem. When out on the lake in gear and with any throttle applied i can ease in the choke and it will run great. However switching to neutral or reverse becomes very difficult because i have to play with the choke to keep the motor running.

I have removed the low speed idle needle and checked it many times and the needle looks like new with the bevels. The o-ring looks good also.

I have read on here about some people who were having similar problems but if seems that after a carb rebuild they were all solved. However i found that after plugging this hole the engine runs fine and as soon as i unplug it the motor starts to spit. Should there be a lead shot in this hole or do i have a problem else where. Please help, thank you all.

 

[ezeke]

Re: Johnson 9.5 HP will not run w/o choke

That hole is always open. I would expect that your high speed jet is clogged.

 

[F_R]

Re: Johnson 9.5 HP will not run w/o choke

Hello i just recently acquired a 1973 Johnson 9.5 HP outboard. Since i got it, i did all the maintenance on it because i had no idea what was done but it was a cherry motor hardly used not even a scratch. One of the things i did was rebuilt the carb and it just does not want to idle without choke (but it was doing this prior to the rebiuld). I have the original service manual for my 73 and i have just about did everything trying to solve the problem. When out on the lake in gear and with any throttle applied i can ease in the choke and it will run great. However switching to neutral or reverse becomes very difficult because i have to play with the choke to keep the motor running.

I have removed the low speed idle needle and checked it many times and the needle looks like new with the bevels. The o-ring looks good also.

I have read on here about some people who were having similar problems but if seems that after a carb rebuild they were all solved. However i found that after plugging this hole the engine runs fine and as soon as i unplug it the motor starts to spit. Should there be a lead shot in this hole or do i have a problem else where. Please help, thank you all.

I'm not 100% for sure positive, but I think that hole is the vent. The book does not show a plug for it.

The larger of the two core round core plugs in your picture has a plastic filler plug behind it, then behind the filler plug are the the very tiny idle passages. They are probably plugged up. Remove the core plug and clean the passages. A new core plug comes with the repair kit.

 

[Rick.]

Re: Johnson 9.5 HP will not run w/o choke

First time I pumped gas to my 73 gas poured out the hole you show in the picture. I put a carb. kit in it and it never leaked from there since. I think your carb. needs more cleaning as well. Using your choke to keep it going is no solution and a classic sign of the carb. not clean or set correctly. Did you remove the high speed jet when you cleaned it? Did you do a link and sync. after you re-installed the carb.? Best of luck. Sounds like you got a nice looking motor. Rick.

 

[halas]

Re: Johnson 9.5 HP will not run w/o choke

FR said:
"The larger of the two core round core plugs in your picture has a plastic filler plug behind it, then behind the filler plug are the the very tiny idle passages. They are probably plugged up. Remove the core plug and clean the passages. A new core plug comes with the repair kit."

Can that plastic filler removed?
Would the carb work OK without the plastic filler? How can it be removed?
I have similar problem with my 9.5 and the rebuilding the carb did not help.
I did replace both core plugs but did not touch the plastic filler. I was kinda surprised to see a plastic filler inside a carb blocking access to cleaning the inner passages.

 

[F_R]

Re: Johnson 9.5 HP will not run w/o choke

FR said:
"The larger of the two core round core plugs in your picture has a plastic filler plug behind it, then behind the filler plug are the the very tiny idle passages. They are probably plugged up. Remove the core plug and clean the passages. A new core plug comes with the repair kit."

Can that plastic filler removed?
Would the carb work OK without the plastic filler? How can it be removed?
I have similar problem with my 9.5 and the rebuilding the carb did not help.
I did replace both core plugs but did not touch the plastic filler. I was kinda surprised to see a plastic filler inside a carb blocking access to cleaning the inner passages.

Well, see it's been a number of years since I've been into one of those but I sort of think the filler plug will just fall out. Maybe a thump on the table top to jar it loose? Earlier models did not have the filler. It was added to improve idle. Seems there was too large a cavity in there for efficient mixture.

 

[halas]

Re: Johnson 9.5 HP will not run w/o choke

The plastic filler plug is available #0312909.
I am going to redo my carb but this time will soak it without the filler plug.
Then put in a new filler plug and larger core plug.
Hope that will take care of the poor idling/stalling.

 

[halas]

Re: Johnson 9.5 HP will not run w/o choke

The plastic filler plug is available #0312909.
I am going to redo my carb but this time will soak it without the filler plug.
Then put in a new filler plug and larger core plug.
Hope that will take care of the poor idling/stalling.

Wow I just got done and this little motor is idling like a dream in the tank.
I could not remove the plastic filler under the large core plug. Soaked the carb body for 24 hrs submerged in carburetor cleaner. It did nothing to the plastic so I put the carb into my woodworking bench wise. Used the smallest wood chisel and cut the darn plastic filler in 4 pieces. The 2 small idling holes were plugged up when I looked through the light. blew it out with compressed air, assembled it and fired it up.
Oh boy what a joy for a Sunday this little thing is purring like it should for the first time since I got it recently.
I did not replace the plastic filler #0312909 for now, and if everything works I will not put one back ever. Just installed the bigger core plug without the plastic filler in there.

 

[Rick.]

Re: Johnson 9.5 HP will not run w/o choke

It's always nice to hear of someones success. Now go and enjoy your motor. They are fun to work on but the greater pleasure is to use them. Rick.