. Backfire through carburetor

[ohiofarmer 3,523]

 Well, this is interesting. I am trying to get either one or both the C 160s ready for snow duty. The eight speed needs a fuel pump  so I started to test the hard/ no start Auto that did not run last year. She just hit the wall on the compression stroke due to weak batteries headed for the scrap pile. I hooked up a known strong battery and ran the engine with some loose juice sprayed in and the spark plug out. By the way Y did shoot some carb spray in as starting fluid 

   Then I hooked up the plug and a strong unburned fuel vapor came out of the carb .

    Where would you guys go from here? I still have plenty of options but C160 machines need to be kept running 

    Thanks in advance my friends 

Edited yesterday at 03:29 PM by ohiofarmer

[Pullstart 71,459]

How is the points gap?  It may be too far advanced (narrow gap?) 

 

Valves need adjusting?

[ri702bill 13,241]

An intake valve that is stuck open will allow the fuel mix in and then escape back into the carb as the spark happens. Usually accompanied by a "huffing" sound while cranking.

I purchased an 854 that sat outside and that is how I know - the intake had stuck open...

[Pullstart 71,459]

52 minutes ago, ri702bill said:

An intake valve that is stuck open will allow the fuel mix in and then escape back into the carb as the spark happens. Usually accompanied by a "huffing" sound while cranking.

I purchased an 854 that sat outside and that is how I know - the intake had stuck open...

Rylee’s Commando 800 was purchased in 2018, part of my little blue truck big show haul.  The intake valve keeper set was missing, and the valve just bounced around in the engine.  

[953 nut 69,931]

A bad condenser can cause backfiring, disconnect the wire from the condenser and see if the situation improves.