Allis C Hard to Start

bisenberger · Aug 14, 2019

My Allis C is very hard to start. I have rebuilt the carburetor, cleaned and serviced the air cleaner. The choke seems to have no effect. I closed it and cranked the engine for 30 second intervals and then pulled the plugs. They were dry. I pulled the fuel line loose at the carburetor and had gas running out. If I open the choke and crank the engine it will try to fire, fire once and kick the starter out.
I have had the carburetor off multiple times and think it is the problem. I feel the plugs should be wet if I am pulling gas when cranking with full choke.
Any ideas

old · Aug 14, 2019

Do some simple trouble shooting.
#1 check that you have a good blue/white spark at the center wire of the distributor cap and at all 4 plugs that will just a 1/4 inch gap or more
#2 pull the carb drain plug and make sure you have a good steady flow of gas that will fill a pint jar in less then 3 minutes
#3 with the air cleaner tube off hold your hand over the carb air intake and try to start it. You should both feel a good suction and also have gas on your hand when you do that. It may even try to start

Bob N.Y. · Aug 14, 2019

Sounds like the carburetor float valve isn't letting gas into the carb.

Steve@Advance · Aug 14, 2019

Like Old said, hold your hand over the air intake of the carb.

It should have strong steady vacuum and your hand wet with gas.

If good vacuum and no gas, there is either no gas in the carb bowl, or the main jet is closed or plugged.

If little or no vacuum, look for valve problems. As in out of adjustment, (too tight), stuck open valve, burned valve, broken spring.

Also a major vacuum leak, or internally burned through manifold will cause low or no vacuum.

marloweg · Aug 14, 2019

check your intake manifold gasket at the head and at the carb to the manifold .the manifold its self for a crack or a rusted out spot. you said you redid the carb did you use a new gasket if not thats the first place to look

47fivewindow · Aug 14, 2019

When my tractors get hard to start the point gap is often too tight. I
usually try a carb fix first because I never learn.

Bob · Aug 14, 2019

Is the choke closing tightly in it's bore?

If there is a "relief flap" in the choke plate is it intact and being held closed by it's little spring?

JD in da UP · Aug 15, 2019

How long have you had this machine? Did it ever start and run well for you?
Give us a little history first please.

bisenberger · Aug 15, 2019

I did the second rebuild on my tractor over a year ago. It is all worked out except the hard to start. It runs perfectly once it is started.
I plan to perform all the test recommended. Some I already have over the last year, but I want to be sure before I replace the carburetor. I sometimes run the battery down before it starts. It has not started easily since I rebuilt it. I had to retime it, replaced all the ignition parts. I have rebuilt the carburetor 2 times, using both carburetor cleaner and then an ultra sonic cleaner. Checked all passages for light and used a welding tip cleaner in all that I could.

JD in da UP · Aug 16, 2019

Added a link that may help. It sounds like you have blocked passages in the carb or some adjustments not right. Do you have the operators manual?
Untitled URL Link

bisenberger · Sep 16, 2019

Old
I did the 3 test you recommended. Both carburetor test came out OK
I did not have a spark jumping a 1/4 of an inch while cranking. None at all. I closed to about 3/16, the tractor started and then the spark would jump, the tractor smooth out and ran OK. I believe I have a weak spark.
I still have the Fairbanks-Morse magneto
Are there some secondary test for that.
If I take it off and play with it on the bench, anything to look for?
Does that magneto turn clockwise or counter clockwise?

Allis C Hard to Start

bisenberger

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old

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Bob N.Y.

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Steve@Advance

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marloweg

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47fivewindow

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Bob

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JD in da UP

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bisenberger

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JD in da UP

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bisenberger

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