Briggs & Stratton / outboard carburetor

[geary]

Guys,
I know this is not exactly and outboard related question but I’m hoping maybe a couple of you might have an answer to my problem ? I have an old snowblower (60’s vintage) with a B & S 8hp flat head engine, This past Oct I went out to try starting it in preparation for winter, it started on the second pull and ran great ! Dec. I decided to try it again, it fired a couple times then quit, it has electric start so I gave that a try, still wouldn’t run just popped a couple times so I figured maybe water in the gas ? Drained the tank and filed with fresh non-ethanol gas, pulled the carb and cleaned it,(not really dirty) !

Everything back together, I tried again, no luck just pops a couple times ! So I thought maybe it has low compression, checked that ( 80 – 85 psi ) Not really bad for 50+ year old engine ! Pulled the head to see if maybe the valves were the problem, timing of them is correct for opening and closing but thinking I’ve gone this far I’ll pull the valves and see how the seats look ? They looked Ok but I thought as long as I have it this far
apart I’ll lap them in and check the clearance, .008 on the intake and .011 on the exhaust, close enough for that old an engine !

Just to cover anything I might have missed I pulled the flywheel as these type of B & S engines have an aluminum key on the shaft and are notorious for sheering, it looked fine with no indication of being sheared !
I also checked the spark and even changed from a points style ignition to an ignition module which has great spark !

Ordered a new head gasket and put everything back together, checked compression (110psi ) Should be good to go, gas on, choke closed hit the electric start. again no go, just a couple pops and backfires ! I am stumped ??? A friend said he thinks it’s a carburetor problem, so my next attempt to get it going is to make a new manifold and try an outboard carburetor ! The carburetor on it is an updraft style and I’ve had it apart so many times I could do it in my sleep. If this doesn’t work I don’t where to go to figure out why it won’t run ?? Any suggestions will be GREATLY appreciated !

Gary

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