Farm Equipment - C wont start hot

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C wont start hot

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=109205
Printed Date: 11 Jul 2025 at 10:40pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: C wont start hot

Posted By: TX fanatic
Subject: C wont start hot
Date Posted: 19 Jul 2015 at 9:07pm

Hey guys I am lost here. I cant figure out what is wrong with it. ALL suggestions welcome!

I have ran this C for a few years now mostly with a sickle mower. This year I put a belly mower on it.

This is what's happening:

It will cold start and run just fine.

It has plenty of power and good throttle response while cold/warm

While I mow it seems to still run fine. The problem starts after I get too aggressive letting out the clutch. If I don't let it out slow the RPMS drop and it starts to stutter. At times I can recover it by pushing the clutch back in and working the throttle.

If i bring down the throttle too fast too far it will quit.

If I shut it off, it refuses to start

What I tried after it quits:

1) pulled the plug from the carb....plenty of fuel running out. (I cleaned the carb today with the same results)

2) checked spark with a wire close to the oil filter mount. (white spark)

3) messed with the mag timing. I loosened the mounts and turned it while trying to start the engine. (eventually I put it back to it original location.)

The only thing that works is wait until its ready to start again.. it may only be 10-15 min

Thanks in advance for your suggestions

Steve

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Thanks Steve

Replies:

Posted By: DougS
Date Posted: 19 Jul 2015 at 9:26pm

Have you messed with the valve clearance lately?

Posted By: SHAMELESS
Date Posted: 19 Jul 2015 at 9:39pm

buy a new coil.

Posted By: DiyDave
Date Posted: 19 Jul 2015 at 9:40pm

And check your condensor...

Posted By: DougS
Date Posted: 19 Jul 2015 at 11:40pm

Is the belly mower blocking the carb in any way? A slim possibility of vapor lock there, especially if you are using E10.

Posted By: Adam Stratton
Date Posted: 19 Jul 2015 at 11:41pm

I would upgrade to a distributor or rebuild your mag. Sounds like a weak coil to me.

Posted By: Dick L
Date Posted: 20 Jul 2015 at 6:10am

Probly loss of compression or points to close. Points could have a burned spot. The first thing I would do is check the head bolt torque and re set the valve lash. Second would be check points. Having to let the clutch out easy leads me to compression but points can do it also.

Posted By: bobkyllo
Date Posted: 20 Jul 2015 at 8:15pm

Shouldnt the spark have been a nice blue spark? TX says its a white spark.

Posted By: DougS
Date Posted: 20 Jul 2015 at 10:39pm

Spark is usually yellow or blue. Blue is desired. What's important is a good strong spark that can jump 1/4 inch or more.

Posted By: Steve in NJ
Date Posted: 20 Jul 2015 at 11:02pm

If its equipped with a "J" series Magneto, it may be one of those units plagued with the tar taped coil. After it gets hot, it leaks and grounds itself to the inside of the housing. When it cools, it fires up again. Tight valves as the guys mentioned is another possibility. As it warms up lash tightens, engine runs poorly and quits. That's one of those issues, that everything needs to be looked at closely to determine the culprit.
Steve@B&B

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39'RC, 43'WC, 48'B, 49'G, 50'WF, 65 Big 10, 67'B-110, 75'716H, 2-620's, & a Motorhead wife

Posted By: TX fanatic
Date Posted: 21 Jul 2015 at 4:43pm

Thanks guys!

Nothing is blocking the air cleaner and I run Kwik Trips no Ethanol added gas

I'll start with the no cost checks moving onto the most likely culprit

I'll check compression cold then move onto the head torque and valve lash. Then check compression and valve lash hot

I'll report back with the additional information.

Thanks

Steve

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Thanks Steve

Posted By: TX fanatic
Date Posted: 21 Jul 2015 at 7:24pm

This is what I did

Cold: checked compression and re-torqued the head bolts. I felt a couple of bolts move before the clicker clicked. Compression from back to front 110,100,110,105 (this is a very old snap on tester....probably only good for reference numbers)

Hot (as hot as i could get it in the yard)

Checked valve lash. two needed an adjustment from 12,13 back to 10

Checked compression back to front 100,100,110 100

Unfortunately I cant check if anything I did fixed the problem because I cant work it hard in the back yard.

How do I know if I have "J" series?

Thanks

Steve

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Thanks Steve

Posted By: Bill Long
Date Posted: 21 Jul 2015 at 8:33pm

I go with SteveNJ, and others who say coil and condenser. We used to have that problem even in the 40's and 50's and it always seemed to be there. Today with the electronic ignition that may be the way to go. Certainty can't hurt.
The other things cannot hurt.
Let us know how it goes.
Good Luck!
Bill Long