Full throttle spit and sputter.

[Don Freytag]

I finally got my clutch pieces and got the tractor back together. I added fuel and removed the bolt from the bottom of the bowl. I got nasty junk so I dismantled the carb and cleaned it out good. Went and got a carb kit and put it all back together after cleaning and blowing through all the holes with compressed air and feeling pretty confident, I made sure only clean fuel was going through and hit the key. Instantly it fired up and purred like a kitten. Then I ran the throttle speed up and it runs like absolute CRAP! I have tried adjusting the carb the governor and I cant get it to run right for anything. I messed with the governor adjustment the timing, I already put in new plugs, distributor cap, rotor, condensor, new copper plug wires, gas treatment (dry gas ) (Just in case), figuring I should be good to go. I am but only at idle! I give up! Help? I do get a noticable difference when adjusting the power needle. I can turn it in till it dies or out till it dies but there is no where in between where it ever runs right just spitting and sputtering. I spent the last 5 hours for nothing trying to get it to run right. After all the money and time I have in it I think if it doesnt get right real quick its going to the scrap dealer!

 

[Don Freytag]

Ok...took the carb back off took it apart and put a small copper wire through the passages and blew it all out again. Put it all back together rechecked the timing, governor, idle mixture and gave it some throttle. Guess what! SOS still runs like crap at full throttle ( .

 

[ken2001]

I just restored a to-35 and had the same thing happen. Have you checked the fuel filter at the carb. There is a fine screen in the fitting that screws into the carb. Also check the sediment bowl where it screws into the tank, there is also a fine screen there as well.

 

[Joe Ferguson]

Hi Don

If the tractor was used for light jobs for long periods there is carbon and gas byproducts accumulated in combustion chamber + sticky valves and rings. If you can plow, disk or put other heavy load on the engine for 15~30 minutes
it will run better and better as it works. I wd not recommand running it at full throttle especially an old engine 3/4 throttle shd be safe.

We experienced spit sputter pif-paf rumble shuffle every year with our TEA'S when beginning to plow after the hay season where the tractors did light works. After 20~30 minutes plowing they returned to normal operation. It was then time for oil change the nex day. We always use premium gas it helps.

Good luck

Joe Ferguson

 

[Don Freytag]

I remove the sediment bowl again and cleaned very little junk from that, I blew out the screen inside the carb from the down stream side and it is clean also. I am going to try and run it again this morning. LOL After a good nights sleep and a couple shots I might be a little less likely to drive it into the creek and leave it there this morning! I am going to try squirting a small amount of brake fluid into the carb while its running. Ive used this in the past to clean out a couple carboned up engines. I'll let you know what happens. Thanks guys for the heads up on the carbon issue.

 

[Don Hooks*]

Don, it might not be the fuel circuit. You have seen the posts before about crossing plug wires and the same thing you describe happens. Apparently, two cylinders firing off-cycle don"t hurt the smoothness of idle (they do reduce the RPMs) but the lack of power on half the cylinders will really mess up the power side of things. Try taking the spark plug wires off one at a time while it is idling and, if it speeds up, that is probably one of the crossed wires. If it almost quits, that is one of the right wires. Other than that, the spark advance might be causing it to fire late which would lose power but I don"t know about running rough.

 

[Jerry/MT]

What tractor model do you have? You never said. 6V sytem or 12v? In my opinion. the governor is the last thing you should monkey with when you have poor operating performance.
However, have you checked the spark to make sure that you have a 1/4 inch long FAT, BLUISH-WHITE SPARK, the color of lightning? If you don't find out why. Have you checked the firing order(1-3-4-2)with #1 cylinder being nearest the radiator and the distributor shaft turning CCW? Have you checked to make sure that the advance mechanism is advancing the spark? Does your coil match the system electrical voltage and is it hooked up so that the primary wire from the distributor to the coil is connected to the coil terminal that matches the battery ground? Check the ditributor for bushing wear by roating the shfat til the points close then pushing radially(side to side) and obeserving the points. The points should not move.

Your power jet screw( the big downward pointing screw) should be screwed out 1-1/4 turns for starters. You can fine tune it later.
Do you have full fuel delivery to the carb? Open the plug at the bottom of the fuel bowl, hold a container under it and make ure the fuel valve at the tank is open. The fuel should CONTINUOUSLY gush out like a cow peein' on a flat rock. Does it? If it dribbles or is intermittent you need to find out why and fix it. Is your choke plate stuck closed ?

Systematically make these checks in the order I have lsited them. Any time you make a change, start up and see if that specific change altered any thing. If you do these checks systematically you should find the root ccause of the problem.

 

[Jerry/MT]

You also need to check for air leaks around the carb metering system, The throttle shaft on the carb, the carb to manifold connect flange and the cylinder head to intake manifold connect flange as well as a crack or rusted out spot in the intake manifold could cause this problem. Spraying starting fluid or propane around these areas with the engine running and observing an increase in rpm when the leaking area is sprayed is one way to do this. BE CAREFULL BECAUSE STARTING FLUID AND PROPANE ARE EXTREMELY FLAMABLE!