Logo

Slow speed needle valve rebuild? 1976 Johnson 35 hp Model 35E76S

jamesfontenot

New member
I cleaned the carburetor and replaced its gaskets . I will reclean the carb since the motor cuts off after running about 20 seconds. This may be partially due to the filter cap of the fuel pump being cracked. Fuel sprays out of the crack when I press the fuel line bulb. I have to press the fuel line bulb to keep the motor running. During this short running period, the motor ran at a very high rpm level once so I cut it off. Next time I started it the it ran at a much lower rpm level. Not sure of why it ran at such different rpm levels? Could this be due to the neelle valve? When I try to adust the needle valve nothing happens with the motors idling speed. I removed the needle valve and the retainer just crumbled so i will replace it. Is there anything else that goes onto the needle valve besides the retainer. There are several pieces in the carburetor kit that I don't know where they go. There is a small plastic funnel shaped piece in the carb kit that may go onto the tip of the needle valve? Not sure though. Can I clean inside of where the needle valve fits with a small wire? Thanks to anyone who can help me!
 
You need to replace the plastic cover on the fuel pump before you can do anything else.

The tight RED retainer you need for the slow speed needle valve is part number 315232.

The carburetor kit includes many items that are for other carburetors. This keeps the part numbers for the kits at a low level.

For instance, that small plastic funnel looking thing IS NOT for your engine BUT rather for the older carburetor needle valve tips... DO NOT attempt to use it on your carburetor. You need to refer to a parts manual, either paperback or online to avoid mistakes.

Yes, you can carefully clean the inside of anything if you desire but be careful. After you replace that fuel pump part, adjust the carburetor as follows.

(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay auction at:

http://shop.ebay.com/Joe_OMC32/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
 
The key when adjusting the slow needle is the engine running at normal operating temp? Preadjust it and then run the engine WOT for at least 5 minutes and then adjust it again. Baby steps turn it 1/8 turn at a time and wait for the crankcase to stabilize. Monitor the head temp by setting your hand on the head and count slow to six. It should be hot enough you want to pull your hand off but dont have to. Be sure and check/adjust engine sync and link every time you pull the carb!



What is and how do you adjust the engine sync and link?
 
Back
Top