Johnson 30HP Needle Bearing

[hornblower]

I'm cleaning the carb on my 1987 Johnson 30HP and have found that there is such a thing as a "needle bearing" located inside the shaft where the tip of the needle valve is. Some parts diagrams do not show this little plastic part but the carb kit I got has it inside and shows it on a diagram.

My problem, I don't know whether the old bearing is still inside the carb. I don't want to slide the new one in and chance getting it lodged in there on top of the old one. I found 1 thread where someone made a tool from a dental pick, bending a tiny hook in the end to slide into the hole and hook the old one to pull it out. I made a hook using thin stiff fish wire and was unable to hook onto anything. Looking into the hole with a flashlight I don't see anything but a smooth shiny metal shaft with a small hole at the end.

My best idea so far is to measure how much of the needle valve sticks out past the body of a carb with needle valve installed, thinking that the needle will screw into the carb body by a 1/16 to 1/8 farther if the bearing is not there to stop it. I've had a lot of help from Jasper60103 and will be getting this measurement from him but thought others might benefit from a thread on this. Chime in if you've dealt with this please.

Andy

 

[Joe Reeves]

Re: Johnson 30HP Needle Bearing

That bearing is used on the older models but I do not think it is used on the later ones. Unfortunately I don't have the 1987 parts book BUT I do have all of the 1986 and the 1988 parts manuals..... and that bearing is not listed. Look closely into that threaded N/V hole, I think you'll find that it is not used.

However, on the carburetors that do incorporate that nylon bearing..... I use a very small tap, just large enough to grab that plastic but not large enough to go thrur it into the aluminum.... guide it in gently with your fingers, then pull it out. Install the new one simply by having it on the needle valve when you install that adjustable needle valve.

 

[hornblower]

Re: Johnson 30HP Needle Bearing

Rats! Just as I thought I had figured it out. I held the bearing next to the carb body while shining a flashlight down the needle shaft and what I saw at the bottom of the shaft did not match the end view of the bearing and so I concluded that I did not have a bearing in there. I was all set on putting this bearing in and my motor would then purr while at idle. Now I tend to think your right that it may not belong in there on this year motor. Looking back at carb diagrams online I didn't see it in the parts list until 1970. On the other hand, I wonder what would happen if I put it in. It seems like it would allow for a much finer adjustment. let me explain,

The friction retainer that goes on the end of my needle was missing when I got this motor. With the motor running this needle was so loose that the torque of the motor would cause the needle to turn itself in. As I said without the friction retainer the needle is so loose it actually wiggles in the hole (and no I don't believe it is worn to that point). Adding the friction retainer on the outside end of the needle holds it in place at that end but I believe it is still vibrating and wiggling on the inside at the tip, something the bearing would cure.

I'm tempted to put it in there anyway if I'm sure I can get it back out. Has ANYONE out there installed this bearing on a late 80's motor?

 

[boobie]

Re: Johnson 30HP Needle Bearing

Leave the needle brg out. It's not required on that mtr. The older mtrs used it but not yours.

 

[hornblower]

Re: Johnson 30HP Needle Bearing

yes sir.

 

[Joe Reeves]

Re: Johnson 30HP Needle Bearing

Installing that bearing would prevent the needle valve from seating properly.

The retainer you require is tha RED nylon retainer #315232.

 

[hornblower]

Re: Johnson 30HP Needle Bearing

I understand and am aware of that. And may I be the first to congratulate you Joe in anticipation of your next post, #1000

 

[jasper60103]

Re: Johnson 30HP Needle Bearing

Hey, Andy.
Just curious, how was the motor running before the carb rebuild?
Did you have problems idling?

jasper

 

[Joe Reeves]

Re: Johnson 30HP Needle Bearing

And may I be the first to congratulate you Joe in anticipation of your next post, #1000

Yes you may my friend. Oh, I see that I also got a promotion with it... from Admiral to Supreme Mariner... Wow!

 

[hornblower]

Re: Johnson 30HP Needle Bearing

Hey, Andy.
Just curious, how was the motor running before the carb rebuild?
Did you have problems idling?

jasper

I just bought the motor. The way the guy demonstrated it to me was with one guy starting it and a friend holding his hand over the carb to choke it. That's the only way it would run. As bad as that sounds and even running choked it just had a smooth sound to it, smoother than several much higher priced motors I looked at so I took a chance thinking no matter what motor I get I won't be satisfied till I go all over it myself anyway.

I reinstalled the carb this afternoon (less the bearing) and it ran OK, although I did not reassemble things completely, leaving the starter off and that means that rod that has a pivot on top for the throttle and timing advance was not secured. It starts easily and consistently. I did not check the RPMs but it idled OK at what I thought was a slightly fast idle. I could move it in and out of gear without it stalling. It revs fine and seems to be a real powerhouse. I'll get it all back together in the next few days and then it's just down to getting it dialed in I suppose.

So far I have changed all fuel lines, fuel pump seems fine. Plugs look new but it seems to be running rich. Once I get it on the boat I can give it a better going over.

Thanks

 

[jasper60103]

Re: Johnson 30HP Needle Bearing

Yea, sounds like once you get her back together and dialed-in, she will purr. Keep us posted.