# 3hp Tecumseh motor running rough



## sluggermike (Apr 19, 2007)

I have an Egar 1, Craftsman lawn edger with a 3hp motor. I just replaced the diaphragm and cleaned the carb. I am having problems getting it to run without missing and also adjusting the idle. There are two adjustments that can be made on the carb. There is the idle mixture screw and the main mixture screw. I've tried adjusting them to make it run smoother, but it doesn't seem to help. It appears to be running rich. I've tried running it with the air filter on and off. It different make a difference. I sprayed carb cleaner around the carb while the engine was running to see it if there was a vacuum leak. It didn't make a difference. I'm beginning to wonder if the problem is something as simple as a bad spark plug. Any suggestions?
Thanks


----------



## glenjudy (Aug 26, 2006)

Wouldn't hurt to try new plug.
Did you remove the inlet needle seat and spring ass'y before you cleaned carb? It takes a very thin walled socket to reach enuf of the nut to remove. I believe a 9/32 with outer wall ground off some will work.
hope this helps,
thanks,


----------



## sluggermike (Apr 19, 2007)

I did remove the needle valve as suggested before I put the carb in the cleaning solution.
Thanks


----------



## Jake T. (May 5, 2007)

Another possibility could be contaminated fuel. Try emptying the fuel tank and replacing the fuel.

Jake...


----------



## pyro_maniac69 (Aug 12, 2007)

did you put the diaphram and gasket on right? because there are 2 different ways they can go on depending on what type of carb you have

if your carb has an F stamped underneath the choke then it goes diaphram against the carb, and then the gasket, and then the plate

if it doesn't have an F stamped on it, you need to put them on opposite of what an F type carb goes


----------



## sluggermike (Apr 19, 2007)

I clean the gas tank and put new gas in it. I will check the carb to see if it has an F stamp on the choke. According to the diagram I downloaded which shows the exact carb I have, the diaphragm is against the body of the carb and the gasket goes on after it and then the plate.
Thanks


----------



## pyro_maniac69 (Aug 12, 2007)

diagrams don't mean anything with the techumseh diaphram carbs, and it isn't on the choke per say, if your looking at the choke side of the carb, and look at the flat part of the body that the plate goes against, that is where the letter will be


----------



## sluggermike (Apr 19, 2007)

I will check for the markings on the carb as instructed. I took the spark plug out and found a lot of carbon on it. I don't know if it has been that way for awhile, or it is that way because it has been running so rich since I rebuilt it. I bought a new plug and will put it in tomorrow to see if it makes a difference. Thanks


----------



## sluggermike (Apr 19, 2007)

I noticed that there was an H imprinted on the side of the carb. Not knowing what that meant I decided to reverse the order of the diaphragm and the gasket. It didn't help, in fact, it didn't allow enough gas to go into the carb and so I put it back the way I originally had it which is the diaphragm, gasket and plate. I replace the spark plug with a new one. After running it for awhile, I noticed that it also had a lot of carbon on it like the old one. I can get it to start, but I can't get it to run smoothly. I have to choke it every time I start it whether the engine is warm or not. I gas cap vents are clean. Any ideas?
Thanks


----------



## bgbass (Jan 11, 2008)

try to decarb the motor get a can of seafoam put some in a spray bottle start motor and spray into carb. shut off remove plug spray in hole let sit for 2 hours start it will smoke a lot when done smoking put new plug in and try.


----------



## sluggermike (Apr 19, 2007)

I will try the Seaforam as suggested. I replace the spark plug, and it immediately carboned up which I believe indicates that the motor is running rich? Will decarbonizing the engine make it run less rich?
Thanks for the help.


----------



## oscaryu1 (Mar 25, 2007)

sluggermike said:


> I will try the Seaforam as suggested. I replace the spark plug, and it immediately carboned up which I believe indicates that the motor is running rich? Will decarbonizing the engine make it run less rich?
> Thanks for the help.


Decarboning it will make it run smoother, idle better, but I'm not sure about the other parts.

SeaFoam is great. Give it a teeny bit at a time though. It was made for cars and their vaccum lines and PCV system, not really for small engines.


ALSO, this could be a sticking valve. Sticking exhaust valve, ect...


----------



## sluggermike (Apr 19, 2007)

I haven't tried the Seafoam yet, but I will soon. How can you tell if there is a sticking valve? I can get it to run smoothly for a short time and then it starts to miss. It's like I know that it can do it, but I don't know way it does it intermittently. I still feel that the problem has to do with the carb. Thanks the help.


----------



## pyro_maniac69 (Aug 12, 2007)

does that still have points and condensor? if so, it might be time to change them, because if you've gone through the carb a couple times and your still getting the same outcome, the spark might not be as strong as it should be

especially since your saying that the plug keeps coming out black, you may have an ignition issue


----------



## sluggermike (Apr 19, 2007)

I believe it is electronic ignition, but I will check. Thanks for the suggestion.


----------



## oscaryu1 (Mar 25, 2007)

If the spark has a sizzling sound, it's good. If it flashes blue, it's good. If it even looks weak... do as pyro said.


----------

