One thing after another

Finally got pump running well on 424 and now it wants to start missing after plowing for about 30 minutes . The muffler and pipe also want to start glowing red . Im going to check time tomorrow but doubt that is the problem. Also plan to pull carb and possibly rebuild as I have read it may be running too lean . I have tried every carb adjustment I can try . Any ideas what might be causing this ??
 
Red pipes are caused by fuel burning as it leaves the cylinder , timing is responsible for this mostly late firing of the cylinder.
 
Before you mess with the carburetor, check/reset the ignition point gap. Then check the timing and whether the centrifugal advance advances timing as RPM's increase.

Timing retarded from spec makes the exhaust hotter and can indeed make the muffler glow. It also causes a loss of power and can result in misfiring.

Keep in mind however that under continuous heavy load it is normal for the muffler on a gas tractor to glow red. This is especially noticeable when working after dark.
 
Check(and reset) timing and points. Sounds like late timing.Easy way to check 'leanness'. Just yank the throttle open as fast as you can. If it stumbles,coughs,sneezes? It's too lean.I cant believe there is no 'load screw' on that carb.Just open it up a turn.
 
I'd check the plugs and see if the engine is running lean. It sure sounds like it is running a bit lean, but could be timing related as well. Is the idle smooth or does it roll and sound loose?
post-10378-0-05724200-1303170504.gif
 

Retarted timing this morning and it ran better than ever. No stumbling upon me yanking to full throttle. . Posed for about 30 minutes and she started missing again. Carb does have main jet power screw and I ve tried that to no avail. Could this be a bad coil ????
 
If it has been sitting up for a while try this in addition to getting the timing right. Clean the glass fuel bowl on the tank even if you do not see condensate in the bowl and be sure to clean the screen at the top. Blow out the fuel line. If you have an inline fuel filter remove it and do not put it back. If the fuel line has been replaced with a rubber hose, get rid of it and replace it with a steel line . . . that has no loops and does not dip below the carburetor. (I think you can adapt a 7/16" steel break line and the compression fittings on one end will screw into the carburetor and the fuel bowl.) The fuel line needs to slope down from the tank to the carburetor with no dips. Make sure the screen at the entrance to the carburetor is clean. Remove the carburetor drain plug and drain and flush out the carburetor bowl. The last thing you ever want to do is fiddle with the adjustments to the carb. If it was running fine the last time it ran the adjustments are fine. They don't just wobble out of place normally. We had this problem every spring after the tractors set up over the winter. Clean the fuel line and drain the carb and it should run fine . . . for a while. When it starts missing again, repeat the process and do not leave any part undone. You can shorten the process if you add some gasoline treatment to the tank. Sounds like bad gas to me. It would usually take about a tank of fresh gasoline and a day of constant use to get it going. WE went through this every spring and the gasoline did not include ethanol.

If this fails you might have an ignition problem but I doubt it.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top