706 dies

my son,s 706 will bog down on road at times ciome to a stop and restart and will runagain. I bought the solinoid shutoff as thought maybe it was shutting off fuel but wasn,t it. I think maybe has something in tank but never nothing in sediment bowl. thanks in advance haying season is getting close. seems to run good in field tho

You need to check your fuel flow from the tank. Could be dirt or rust in the tank. When it quits running check for fire to your sparkplugs ASAP when it stops. If there's no fire or weak fire could be the coil getting weak when it gets warm.
Hal

Check for any debris in the fuel tank. A leaf or other debris may cover the stand pipe in the tank and then move off again allow for the quick restart.

Just as well pull the fuel line and run it into a gas can. Should have good flow for at least 5 minutes. Drain the gas. Pull the sediment bowl and then flush the tank. As old as the 706 is, it probably has big chunks of rust or a leaf up there.

If rust, you can acidize the tank. Ask later or check the archives here about that. Then get a piece of 1 inch or two or so fuel line or plastic line that will fit over the sediment bulb stub that sticks up into the tank. That will keep the bottom dwelling crud and water from getting into the fuel. 2 or 3 wraps with window screen sticking up into the tank a couple inches and wire tied at the around the stub will work too.

Post back with what you find out. Running down the road in road gear hitting all those bumps is moving all that rust and crud around. You may get good flow with the tractor sitting or running steady in a field but I'd bet your farm there is rust in there.

I replaced my solenoid with a regular jet, nut, and packing. Now I have an adjustment if I ever need it.

When you pull you sediment bowl, you might think about adding a quarter turn plumbing valve from the hardware store with a couple brass nipples. I acidized my tank but still had rust come back so I added a drip leg like used with natural gas going into a furnace or water heater. Came off the drip leg with a tee and then added the sediment bowl. Since the sediment bowl shutoffs don't close half the time, I added the plumbing valve after that but it might have been better to put it before.

It isn,t spark cause will start right up. just before it dies it will start smoking black

Very good chance you have to high heat range spark plugs in. If you have the plugs the books recommend they are to hot for todays fuel. Put in Champion D15Y or other brand equivelent.