850 will not run

thommoos

Member
57 850, 6 volt points, just replaced , cap, coil, plugs, overhauled carb, because it would loose power then shut down . Will not start, just spits and sputters, I've tried starting fluid, still no running. Engine spins over quite well. I have a white spark at coil wire. When's choke it you gat gas , so I resorted to pull starting and it kinda ran at full throttle, but it would back fire and spit, cough the quit. I went through the carb not it worse than before. What in the world am I missing here?
 
I would double check the firing order. 1243 CW. Make sure #1
wire is where the rotor points when #1 cylinder is at TDC on
the compression stroke.
 

starts, runs fine, and then shuts down?


restricted gas flow, or intermittint spark...

if it will not fire on starting fluid,, its either flooded or no spark.

could be bad ignition switch, bad coil, bad condenser, bad wire to coil, dist.

could be carb is filling up with gas and flooding, or gas is restricted and the carb slowly emptys the bowl and runs out of gas...

pull plug on bottom of bowl... let gas run out.. catch it in a can.. see how long it runs out and does it slow down to a dribble or keep the same flow... if it keeps the same flow, then is NOT running out of gas. so its flooding or loosing spark.


if only when hot it could be vapor locking due to gas boiling in gas line due to heat... you cant hold your hand on the gas line, its too hot.
 
Will the spark jump a 1/4 inch gap or more?? At all four plug wires also. Did you pull the dust cover and in doing so loose the rotor clip?? Have you check to make sure the point gap is correct at 0.025??
Have to pull the carb drain plug and made sure you have a good steady flow of gas that will fill a pint jar in 3 minutes or so??
 
Double checked since I have low light spark at ponts, nice white spark .025 gap, coil wire arches at a ground point shoot about 3/8 arch white
in color. No fire t plugs , I lm lost
 
How are you checking spark at the plugs? Same as the coil?
If you have spark at the coil wire and no spark to the plug wires
that leaves the cap and rotor. Still got the old ones to put back on?
 
I think I still have them. This is why I replaced them The cap and rotor, point and condenser, and coil, had no spark. Then it started shutting
some said hey I got spark which got me to thinking pit was fuel.

So what I am missing not having spark at the plugs?
 
Spark at the plugs mean nothing if it will not jump a 1/4 inch gap or more. Anything less and the spark is to weak to fire an engine
 
Wires were in the list I mentioned.

Rotor and cap are kinda bulletproof if made right, I have seen mismade damaged rotors that were cracked and shorted spark. Condensir is good if it makes spark, testing at coil wire.
 
Ah but are you buying them at TSC or a good parts place?? If TSC your likely to be getting stuff from the land of almost never right but if you buy form say an O'Reilly's auto parts or Napa well then good chance they are good
 

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