Farmall 450 running issues

[Thorny50]

I have a Farmall 450 that ran great a couple years ago and now it has issues staying running. It will start right up and run for a few seconds and then backfire, pop and then die. I have taken the carburetor off and rebuilt it but am still having the same issue. It has good clean gas in it so I'm wonding if it's an electrical issue? Any help would be appreciated. Thanks!

 

[Janicholson]

Welcome to YT forums. Simple things first. Using a open topped clean can, with the tank sediment bowl valve open, Remove the drain plug in the bottom of the carburetor bowl. There should be a rush of fuel, then a steady flow of a pint every minute and a half or 2 min. If the rush is there, and then slows to a very low flow/drips, the supply system is likely to be plugged up. the tank outlet could have an obstruction, the screen in the sediment bowl could be plugged, and the screen at the fitting into the carb could be plugged. It is possible that the needle and seat could be plugged as well, less likely. Check that first. Jim

 

[BarnyardEngineering]

Tell us more. "Ran great a couple of years ago and now it has issues staying running." Does that mean the tractor has been sitting for a couple of years? Or, have you been running it regularly these past two years, and it suddenly started having issues?

If the tractor starts right up, the timing has to be somewhat right. That means the backfire is probably due to fuel starvation.

It *could* be electrical but you'd have to troubleshoot that. Test for spark immediately after the tractor dies.

 

[Thorny50]

I got the tractor about 4 years ago and it ran great. It sat over the winter and started having these issues where it will run for for 30 seconds to a minute and then starts to backfire and surge then die. The carb has been completely gone through, new sediment bowl and I put a new fuel line going from the sediment bowl to the carb. The sediment always appears to be full. Thats where Im at currently with it.

 

[Janicholson]

Do the tin can test!! Jim

 

[used red MN]

I got the tractor about 4 years ago and it ran great. It sat over the winter and started having these issues where it will run for for 30 seconds to a minute and then starts to backfire and surge then die. The carb has been completely gone through, new sediment bowl and I put a new fuel line going from the sediment bowl to the carb. The sediment always appears to be full. Thats where Im at currently with it.

Hello Thorny50, welcome to YT! A sediment bowl full of gas tells you nothing other than enough gas has made it out of the tank to fill it. There is no way to tell how much fuel is passing through it by looking at the outside. The meaning of “the carb has been completely gone through” has a lot of different meanings mostly based on how much experience you or whoever went through it has working on these types of carburetors or really any for that matter. Look at the item in the link. Have you seen it before? If not your carb job was not “complete”! That is the fitting that the fuel line screws into where it connects to the carb. That is a fine “strainer” screen that can plug. The difference between the flow out of the carb plug and the actual line will tell you if it is plugging. The sediment bowl should have a round screen in the top that is where the main filtering should take place. The small strainer in the carb is only a safety catch to stop problem debris. We can’t completely ignore the ignition, but by your symptoms I agree with others the fuel flow test should come first.

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[Thorny50]

When I was replacing the line from the bowl to the carb, I turned the gas on and had good flow. I also put a new screen in the carb where the gas first comes in, so I was thinking the carb was getting enough gas. Thats where I started to lean toward the electric side of things like possibly the coil or distributor.

 

[Janicholson]

When I was replacing the line from the bowl to the carb, I turned the gas on and had good flow. I also put a new screen in the carb where the gas first comes in, so I was thinking the carb was getting enough gas. Thats where I started to lean toward the electric side of things like possibly the coil or distributor.

Please understand we are out here with experience you can see the tractor. The tin can test is a must for satisfying our "feeling" toward the issue. Jim

 

[Thorny50]

Please understand we are out here with experience you can see the tractor. The tin can test is a must for satisfying our "feeling" toward the issue. Jim

I appreciate the help and ideas. I will this test and double check everything else. I seem to be running out of patience for this tractor but not wanting to give up on getting it going again.

 

[DaveBN]

Well you could clean the points, that's easy to do. Run very fine Sandpaper thru them then a folded dollar bill to remove any dust left over. Is the coil hot to the touch when it dies? Is should be very warm but not hot enough to burn your hand. Did you service the air cleaner? Maybe you have an obstruction there. Have an extra spark plug handy and when it dies pull one wire and connect it to the spare plug and see if it sparks when trying to start the engine.
Dave

 

[Janicholson]

I appreciate the help and ideas. I will this test and double check everything else. I seem to be running out of patience for this tractor but not wanting to give up on getting it going again.

At 75 years old, And a professor for 50+ years I have learned patience is beyond a virtue. The tractor is going to be fine. It is one of the best Farmall 3 number series ever made and worth being a learner about. Jim

 

[Brownie450]

If the fuel delivery checks out, the condenser would be my first
thing to check out in the electrical department. Of course
everyone is having problems with new condensers also.
Check the air cleaner cup for dirt build up.
Jim