Posted by JIM C. on October 12, 1997 at 17:42:23:
In Reply to: Re: WON'T START EASY! posted by Alan Bowes on October 12, 1997 at 00:26:36:
: : Once it gets running, it is like a brand new engine. Good power, no miss, doesn't starve for fuel at high or low rpms, never floods. After it warms up, you can shut it down and restart it fine, with no starting fluid, but once it cools down, forget it. Changing the timing has had no effect and the points and condenser have been replaced. The choke has no effect either. The weak spark theory may have some merit. What could cause it? Compression check done today yielded less than peak compression (as expected) but it was consistent throughout. I forgot to mention that this truck sat in a barn for 23 years without use. Any clues there? Gas in the tank was all "varnished" but I never emptied it, I just ran it through. Mistake? The truck has been appropriately named "MULE" by my wife due to its stubborness. Thanks for everyones help and keep your ideas coming. The farmers corn was just harvested so I have (28) acres to "play in".- JIM C.
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: The fact that it starts OK when it's warmed up but not when it's cold suggests either poor compression, a weak spark, bad gasoline, disfunctional choke, timing off, or some combination of these or other factors. When an engine is warm, the warmth helps do the job that the compression is supposed to do when cranking the engine (helping to heat/vaporize/atomize the air-fuel mixture to make it easier to ignite). A properly "prepared" mixture is easy to ignite, even with a weak spark. Also, a warm engine tends to crank a little faster than a cold engine and draw less power from the battery, thus giving more compression and a better spark at the same time. The temperature may also effect how well the rings seal, due to their being recently oiled, plus a possible positive effect from dimensional changes in the rings and piston.
: When you said you ran the old gas through, that made me shudder a bit. I assume that you at least added mostly fresh gasoline first. If there's a significant percentage of ancient gasoline, it could certainly make it harder to start the engine, since the more volatile components would have evaporated long ago, leaving less volatile components behind that are much harder to ignite.
: What happens if you prime the carb with about half a teaspoon of fresh gasoline before starting?
: Have you checked your plugs for deposits?
: Have you checked to see if you're getting a good spark while cranking the engine?
: Have you checked the timing? This can make a difference if it's off a significant amount.
: Alan
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Alan, thanks for your help! Turns out the timing was off quite a bit. Starts great without starting fluid. Now my wife will get off my back to sell "MULE". Thanks again.