**HELP** Briggs and Stratton 3hp wont start.

#1
Hey everyone, I have been restoring this old Briggs engine for a mini bike project. Before I took it apart to paint it, I replaced the magneto coil, and it fire right up. Once I finished the paint and reassembled it, I tried to start it, and it would not go. I sprayed starter fluid into the intake, and tried to start it, all it did was fire for a few seconds, but didn’t run. The spark plug is new, I replaced the magneto coil, and cleaned the carb thoroughly, I don’t know if the gaskets are the cause of the problem, since I reused the old ones. I am stuck. Fyi, this Briggs does not have a float bowl on the carb. It’s the old style from the 70s
 

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#6
They had a vaccu-jet on the 3.5hp?
The carb in the photo provided by the OP is a Vacu-jet. You can tell by the horizontal orientation of the choke pull (as opposed to vertical on the Pulsa-Jet carb). In addition, that small (1 QT) fuel tank is another tip off as there is no upper fuel cup/reservoir on these small tanks, and accordingly, only 1 fuel pick up tube on the (Vacu-Jet) carb. You can tell by the photo that this engine has had some sort of "restoration" (at least new paint and decals) and the spark plug wire tells us that it has been switched to electronic ("Magnetron") ignition. I have seen OEM Briggs 3HP engines that originally came with the smaller tank and Vacu-Jet carb- it depends on what application they were designed for.

The bigger question on this engine is just WHAT is original? Was the tank and carb switched at some point? Was the recoil shroud switched? That COULD be a 2 HP engine with original tank/carb that someone installed a 3.5HP shroud? There are ways to tell, however, the OP will need to do some forensic work and provide us with some information.
Michael
 
#8
Are the valves seating?
Intake clearance .005" to .007"
Exhaust clearance .007" to .009"
Depending on which Briggs repair manual you use you will see exhaust valve clearance listed at either .007"-.009" or .009" - .011" I have always only used the latter with good results.
Michael
 
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