scout not firing up after carburetor rebuild

B

bsgreeley

New member
If anyone can point me in the right direction here- admittedly I am not much of a mechanic...

I had my carburetor rebuilt by ihnorth- and upon reinstalling, the truck is not starting up...

I have re-connected all the lines back to the carb exactly as I pulled them off. And from what I can tell all the carb functions are functioning.

I disconnected the battery during the month that the carb was off so that the battery would not drain. And when I turn the key the the electric fuel pump starts up like it should and fuel definitely is in the line. When I fully turn the ignition, the engine cranks and cranks but does not fire up. I was able to start it a month ago right before I removed the carburetor.

Can anyone think of something I am overlooking?
 
Unless that carburetor was somehow damaged in return shipping ben, it is not the problem. The attached pic shows it running at idle on my test engine, so it already as at least 20 minutes run time.

Verify that both mounting nuts were tightened alternatively and are tight. Verify that the distributor vacuum advance tube is connected. Verify that you have a nominal 5psi of fuel inlet pressure with a delivery rate of one pint of fuel in 20 seconds of cranking.

Is the choke cable properly connected and are you choking the carburetor with the cold engine? Normally takes a choke plate setting of 1/2 closed to cold start the engine when everything is proper.

Verify also that the fuel filtration system is up to snuff and there is no blockage at all in the delivery system. Fuel must also be fairly fresh.

Also do a spark check at one spark plug with it grounded to the engine block to verify that you do have ignition.

I'll be spending 6>8 days in the dfw area starting on May 28, so I will definitely make a time to stop by and provide personal assistance!
 
michael mayben said:
unless that carburetor was somehow damaged in return shipping ben, it is not the problem. The attached pic shows it running at idle on my test engine, so it already as at least 20 minutes run time.

Verify that both mounting nuts were tightened alternatively and are tight. Verify that the distributor vacuum advance tube is connected. Verify that you have a nominal 5psi of fuel inlet pressure with a delivery rate of one pint of fuel in 20 seconds of cranking.

Is the choke cable properly connected and are you choking the carburetor with the cold engine? Normally takes a choke plate setting of 1/2 closed to cold start the engine when everything is proper.

Verify also that the fuel filtration system is up to snuff and there is no blockage at all in the delivery system. Fuel must also be fairly fresh.

Also do a spark check at one spark plug with it grounded to the engine block to verify that you do have ignition.

I'll be spending 6>8 days in the dfw area starting on May 28, so I will definitely make a time to stop by and provide personal assistance!
Click to expand...


Michael,

I will re-check each point.

Question: can you go more in detail about the spark plug check?
 
Remove whatever sparkplug is easiest to access. Plug it into the cable and then ground the plug body well to the engine. Then have someone crank it over from the ignition switch while ya watch for a good, fat spark at the plug tip.

If ya have spark at the plug, and ya didn't move the plug cables around or remove and replace the distributor since it last ran, we hope to see spark. If no spark, then an ignition issue is preventing the engine from starting. If the plug was black and/or wet with fuel residue when you removed it, that indicates that the plug is not firing.

So what we are doing here is making a diagnostic regarding what we are lacking as far as engine run. If you are certain that proper fuel delivery is being made continuously to the carburetor fuel inlet, remove the air cleaner and leave it off until we get the engine running again. If you do have spark at the plug, then give the carb air inlet a simple squirt of carb cleaner from a spray can and see if will then start. Carb cleaner is much more volatile than regular gasoline.
 
michael mayben said:
remove whatever sparkplug is easiest to access. Plug it into the cable and then ground the plug body well to the engine. Then have someone crank it over from the ignition switch while ya watch for a good, fat spark at the plug tip.

If ya have spark at the plug, and ya didn't move the plug cables around or remove and replace the distributor since it last ran, we hope to see spark. If no spark, then an ignition issue is preventing the engine from starting. If the plug was black and/or wet with fuel residue when you removed it, that indicates that the plug is not firing.

So what we are doing here is making a diagnostic regarding what we are lacking as far as engine run. If you are certain that proper fuel delivery is being made continuously to the carburetor fuel inlet, remove the air cleaner and leave it off until we get the engine running again. If you do have spark at the plug, then give the carb air inlet a simple squirt of carb cleaner from a spray can and see if will then start. Carb cleaner is much more volatile than regular gasoline.
Click to expand...


Ok thanks michael- I did the spark plug check per your instructions and it was not providing a fat spark upon being grounded to the block when cranked- just a weak spark. I will replace the spark plugs and look for a better result.

I did try at the same time a dash of carb cleaner down the intake with no postive results.

We shall see what a tune-up does. I will let you know.
 
You must log in or register to reply here.
Back
Top