Farm Equipment - C puffing smoke, thoughts

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C puffing smoke, thoughts

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=141442
Printed Date: 01 Jan 2026 at 12:03am
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Topic: C puffing smoke, thoughts

Posted By: VTdirtguy
Subject: C puffing smoke, thoughts
Date Posted: 14 Aug 2017 at 11:12am

http://www.youtube.com/watch?v=nde4J4K4k20" rel="nofollow - https://www.youtube.com/watch?v=nde4J4K4k20

Hey all,

I lurk here most days and don't post a lot. I recently had to replace the coil and condenser in the FM magneto on my C. I finally got it timed back up after a few frustrating hours of learning about magneto timing (thanks to this site!). Now with a fresh oil change she is running for the first time in a year, and only the second time in 25 years. It only has one hiccup that concerns me. The puffs of smoke that you can see in the video. This seems to be at all rpm ranges not under load. I'm leaning towards a valve hanging up. What do you guys think?

Thanks,

John in VT

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Grampa's old C got a whole new lease on life.

Replies:

Posted By: Hubert (Ga)engine7
Date Posted: 14 Aug 2017 at 12:01pm

The smoke looks blue which would indicate burning oil from somewhere. May be a bad spot in a valve guide letting some oil get by.

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Just an old country boy saved by the grace of God.

Posted By: Steve in NJ
Date Posted: 14 Aug 2017 at 12:53pm

Running the engine doesn't sound bad. I noticed just before the smoke appears there's a little miss. That sounds to me like it could be a loose valve guide where oil enters the combustion chamber via one of the valve guides, splashes the plug and goes out as a little puff of blue smoke. Just my opinion. Did you ever adjust the valves at all? Sometimes a tight or loose valve can cause a miss. If the guide or guides are loose, the valve adjustment won't help usually with the smoke issue tho...
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: VTdirtguy
Date Posted: 14 Aug 2017 at 1:23pm

I'll run the valves next time I pull it in. I don't mind the smoke just the skipping is of concern to me. I appreciate your really quick responses. I love this site!!!

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Grampa's old C got a whole new lease on life.

Posted By: TimNearFortWorth
Date Posted: 14 Aug 2017 at 2:17pm

Fresh gas, full can of Seafoam for 1/2 - full tank.

Seafoam in crankcase also does wonders, just don't leave it in and go work it as it can potentially clean enough deposits to effect screen in pickup if very dirty. I run em' till good and warm, add Seafoam and run at high idle to 1/2 throttle for 20-30 minutes, drain with plug left out overnight, fresh fill of quality oil and new filter.

I change the filter again after 20-30 minutes of using the tractor and getting her warmed up well. This has worked well for me, especially on units that have sat for some time, even if they shown good oil pressure.

Pull the valve cover after treatment, to see what Seafoam actually does for cleaning.

Posted By: DennisA (IL)
Date Posted: 14 Aug 2017 at 2:24pm

Seafoam is great stuff!

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Thanks & God Bless

Dennis

Posted By: Dick L
Date Posted: 14 Aug 2017 at 3:20pm

I go along with checking the valve clearance. The puff of smoke now and then rather in any type of rhythm has me scratching my head for a positive thought.

Posted By: Hubnut
Date Posted: 14 Aug 2017 at 6:12pm

I had a similar problem in a B. In my experience, the rings were shot. I only saw smoke faintly, but it would puff blue like that regularly on a miss. Eventually it got worse. One thing to consider. You said it hasn't run in a while. I'd run her to temp for a good while and see what shakes out. Lastly, I agree with others, I'd adjust the valves first.

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1940 B "Lucy"
1941 B w/ Woods L59 "Flavia"
1942 B w/ finish mower "Dick"
1941 C w/ 3-point "Maggie"
1947 C SFW w/ L306 "Trixie"
1972 314H

Posted By: CrestonM
Date Posted: 14 Aug 2017 at 6:22pm

If you let it get hot, then sit for a while, does it smoke on startup? That could mean a worn valve guide...

Like Dick, I'm a little confused as well, but it does seem like guides to me. I'd do a compression check with and without oil in the cylinders and see what the results are.