Reel Repair by Alan Tani

Hey Guys,

I've got a two stroke motor which is running my rototiller.  It keeps cutting out when it sits level, however I can run it for longer periods of time when it is canted back with the tines facing up.  I thought I'd post this here in case someone else had this same problem on their outboard in a similar canted configuration.

I removed the carb and cleaned it in the US cleaner.  That seemed to help, but it's hard to keep this motor going for very long.  Spark plug and fuel are new.  Starter fluid can get it to start, but it ends up sputtering out. 

Any advice would greatly be appreciated,

Matt

Hi Matt. Kinda sounds like a fuel flow problem. Vapor lock? Stuck needle valve?

Seafoam or Stabil?  Run it out of gas before you put it away?

Hi Matt —-

Carb may still be messed up.

You can purchase a new complete carb on Amazon or e-Bay really cheaply.

But, before going there —-

Air cleaner must be fresh and new —- and the gas filter must be fresh and hopefully new also.  Plus, the pickup tube and pickup tube end in the gas tank must be clear of any crud.

Next, see if there is any progress and if it will keep running.

If so —- next adjust your HIGH & LOW speed screws on the carburetor. Then, if equipped, your LA screw (idle adjustment.

First the high speed —- if equipped with limiter caps —- remove these temporarily for the adjustments.

Turn both the low speed and high speed adjustment fully clockwise until they stop —- then back each off 1 1/4 turns.

At this point, you fine tune the high speed screw by running the engine at full throttle and adjusting the screw for optimum speed —- then back it off a bit.

On the low speed screw —- adjust it so that it is running smooth at slow speed without dying —- then move it slightly up so it won't die.

Finally, adjust the LA idle screw.  This just keeps the throttle at the place where it runs the best.

If none of this works, or is not possible —- then I would purchase a new carb, install it and go from there.

I always run a little Seafoam in my equipment to keep things from gumming up before stored away.

If you don't want to attempt this —- any small shop like a lawnmower shop would be the ticket.

Let us know.

Best, Fred

Does the carburetor have a diaphragm. If it does its probably gone bad.

Seafoam as mentioned

Do you use gas tainted with ethanol?

Quote from: mikeysm on June 27, 2024, 01:36:59 PMDoes the carburetor have a diaphragm. If it does its probably gone bad.

Most likely the carburetor does have diaphragms and as they lose their flexibility and become stiff , the engine performance suffers. The reason the diaphragms become stiff is mainly because of ethanol gasoline. That is not to say they won't become stiff with non-ethanol gas, they will eventually but not as quick.

The design of most 2-cycle engine carburetors use the diaphragms as a pump to move the gas through the carburetor to the intake of the engine.  When the diaphragms stiffens, you'll see early signs of issues and eventually you won't be able to start the engine. 

You're best bet is to replace the carburetor with one of the cheap knockoffs. If you're handy, also pickup the diaphragm kit to rebuild the old one to have a replacement on hand. 

Here's a quick video with explanation -- https://www.youtube.com/shorts/6XiGT_HeyuE

Hi Folks,

Thank you all for the great replies and the time you put into replying.

Where do you all suggest placing the seafoam?  In the gas tank?  The gas is relatively new and runs other 2 stroke motors around the home fine.  I also use a fuel stabilizer for storing, but unfortunately, the gas does have ethanol as that's all that's around. 

I am able to start-up the engine without the air filter and use starter fluid when it doesn't kick over immediately upon pulling a few times. 

When I pulled the carb and disassembled it, I also dropped it in what I thought was the diaphragm to the ultra sonic cleaner.  I believe that is a cloth like membrane that sits on top of a gasket. 

I took a look at the manual for adjusting the carb.  It looks like I have a mixture adjustment screw and and idle speed adjustment screw.  Which would be the preferred adjustment to be made first?

Thank you again everyone,

Matt

Internal carb adjustments?  I know from my Johnson outboard that you need to have two measurements on the float.  These would be the float height and also the float drop.  Do not assume these will be correct when you replace the float with a new one.

Frank

Most likely the ethanol has messed up your carburetor and it needs to be rebuilt or replaced.

I think I found a culprit.  Pardon my ignorance but the part in the red box swings when I pull on the throttle, however it does not come back to a natural state, or swing back fully.  Is that part supposed to swing back, presumably against the mixture adjustment screw? 

If so, would that be adjusted while resting back against the screw?

Thanks All,

Matt

What is the model of your rototiller ,look at the picture I don't recognize any part that look alike

It is part of the throttle linkage to the carburetor.

This is a Craftsman model 536.292521.

I believe both the throttle paddle on the intake side and perhaps as you mention the linkage on the bottom do not "reset" back to their default state.  I'm just not sure at what state the linkage needs to be in to make the adjustments.

If you pull the throttle it will open paddle near the intake but, it does not flap back closed nor does the linkage on the bottom of the carb where I posted the photo.  I'm not sure if this is the true cause or just another problem, since the throttle stays at full basically most of the time.