Scout car stalling

[Robert Cassin]

OK, I know it is for HTs but you guys are really good and there is really no forums for  White Scout cars which is the trouble vehicle that I asking for help with. After about 15 minutes of running fine she stalls, back fires and then wont start until about a 10 minute rest. Here is what i did: Wrapped the carb and gas lines in heat shield, loosened the gas cap, took the fuel pressure regulator off, and put Seaform in the gas. changed  the coil . I ran it for 30 minutes in 95 degree temps. Not driving but just letting the engine run and increasing the RMPs often. It ran flawlessly.  I am using an electric fuel pump and the supply lines are away from any heat, the fuel filter is new. . The carb does sit very close to the manifold. I ran it today for a parade and it did it again, stall after about 10 minutes. I also cleaned the carb which I suspect is the cause. I think next up is to send it out to a pro. They can clean it better than me with the new technology, ultrasonic cleaning. Any help would be appreciated, Thanks, Rob

[woodwalker]

Do you have the heat shield installed under  carb?

[Robert Cassin]

I do have it wrapped  with a high tech heat shield but who knows if it is working. The carb sits right on that dam manifold.  I am going try a spacer on the carb next. Thanks

[8683jb]

I don’t know about the scout cars Rob, but on the half tracks, instead of the carburetor sitting directly on the manifold there is a phenolic-like insulating block under the carburetor. I’ve seen the insulators on ebay and other sites. Good luck and keep us posted.

[woodwalker]

There is a metal shield that bolts on top between carb and manifold.

[woodwalker]

https://www.google.com/search?q=m3a1+scout+car+engine&client=tablet-android-samsung&prmd=isvn&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj2yMiGkIfcAhWmjVQKHcjtCMMQ_AUIESgB&biw=1024&bih=768#imgdii=tVGrVlHBLbNjdM:&imgrc=h55V3jaDE5n2WM:

[8683jb]

Wow - Completely different critter! I toldja I didn’t know about scout cars. Thanks woodwalker.

[Robert Cassin]

Thanks for all the help!

[autocar925]

Sounds to me more like an ignition problem.  When a ignition coil or distributor capacitor(condensor) get hot, they can stop working.  Let them cool down for awhile and they come back to life.

Next time it stalls, if someone is with you, you can pull the coil wire and hold it near a ground.  Have the other person try and start the engine.  Should throw a spark.  If it doesn't, bad ignition.  If it does, bad fuel system

If by yourself, spray starting fluid into the air cleaner.  If it doesn't run, bad ignition.  If it does, bad fuel system.

The only caveat to the above is if the engine is being flooded(for instance a stuck carb needle valve)-it will have spark and starting fluid won't do anything.  If this is the case though, you should be able to smell the gasoline cooking off in the manifold.

If you can separate the problem to either fuel or ignition, it tells you where to start looking and you can usually find the problem pretty quickly after that.

[Robert Cassin]

Thanks for all the help!

[Hammerhead]

One other thing to think about is so many of the fuels now have Ethanol in them.  That will gum up your Carb for sure.  And your fuel system.  That could make your vehicle run rough and die.  Always run Premium with NO Ethanol.  You might have to look for a station that has it but locations that serve boaters will have it.  I learned the hard way with my CCKW.