Topic: 1988 48HP Johnson Carb Question – Antique Outboard Motor Club,Inc

This topic has 13 replies, 8 voices, and was last updated 9 years, 6 months ago by fleetwin.

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May 20, 2015 at 1:50 pm #1550
kevinrude
Participant
My buddy Bob has a 1988 48HP Johnson that he’s having issues with. The motor stalled out on him and when he checked the carb he found the needles shut down tight. He was able to loosen them 3/4 – 1 1/2 turns as suggested by the manual, but once he started the motor the needles rotated clockwise into the shut position again. So, is this just a matter of the needles needing re-packing or is it something else? Thanks.
May 20, 2015 at 2:05 pm #16514
hag
Participant
Probably the packing and the locking nut is loose or nonfunctional.
May 20, 2015 at 2:51 pm #16518
Mumbles
Participant
1988? That motor should have fixed jets (orifices) instead of adjusting needles! Are you sure it’s the original carb or powerhead?
May 20, 2015 at 7:06 pm #16539
fleetwin
Participant
US Member - 2 Years
Yeah, something is not right if the carbs have adjustable needles. Post some pictures so we can see what you have.
May 20, 2015 at 10:56 pm #16549
kevinrude
Participant
Thanks for the responses. I’ll see if Bob can shoot me some pictures.
May 21, 2015 at 10:32 am #16580
jerry-ahrens
Participant
I believe the low speed circuits on those are adjustable. They don’t use a packing nut like we are use to but instead have a replaceable plastic bushing that the needle screws in to. If your’e carefull you can replace the [red] bushing without removing the carburetor.
May 21, 2015 at 12:46 pm #16592
pappy
Participant
US Member
The carbs on that engine are fixed jet as has been said already.
Either the carbs have been changed or the engine is not a 1988.
Most of the adjustable carbs had a needle (no red plastic piece) that ran on a tensioner spring. The needles would not move by themselves.
Could he have a 1998 instead? That year had adjustable carbs.
May 21, 2015 at 6:04 pm #16608
fleetwin
Participant
US Member - 2 Years
Yeah, could be a 1989 or newer with the little adjustable needles on the side of the carb. But, I honed in on the comment that the needles were "loose" and thought of those earlier carbs from the 50hp engines from the early 70s.
Pictures will tell the tale.
May 22, 2015 at 11:19 am #16649
jerry-ahrens
Participant
I see now after looking at the parts book that I was incorrect on the needles. My mistake. I guess I’ve never worked on those style carbs.
May 23, 2015 at 2:53 pm #16710
kevinrude
Participant
Here are the pictures that Bob sent me:

This is a photo of the needle that he has been adjusting:

This is the hole that the needle is accessed thru:

This shows the location of the access hole on the motor:

Here is a picture of the hood which hopefully will answer the 1988 vs. 1998 question:

Thanks again!!
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