Antique Engines and Old Iron
[Home] - [HELP] - [Forums] - [Articles] - [Photo Gallery] - [Groups] - [Chat] - [Classified Ads] - [Subscribe] - [Links] - [Books] - [Sponsors] - [eBay Tools]

Go Back   SmokStak > SmokStak® Antique Engine Community > Antique Gas Engine Discussion
Forgot Password? Join Us!


Antique Gas Engine Discussion Meet collectors of hit and miss engines, ask questions about collecting, restoring and showing antique flywheel engines.

Antique Gas Engine Discussion

Thermoil Head and Cylinder Cleaning

this thread has 3 replies and has been viewed 1235 times

Thread Tools Display Modes
Old 08-01-2005, 09:49:56 AM
midpw midpw is offline
Join Date: Feb 2005
Location: St. Ignace, Michigan USA
Posts: 914
Thanks: 702
Thanked 251 Times in 180 Posts
Question Thermoil Head and Cylinder Cleaning

Hi Guys,

I have a 7 HP UA Thermoil and I have finally dragged out of storage to begin work. It was stuck with the piston about 3/4 in toward the head and I backed the piston with some soaking and persuasion on the crank shaft. I cannot get the piston and crank "through" TDC, It hangs up and I have to back off. The motion is smooth throughout the rest of it's travel.

I assume that the cylinder and piston and head are pretty well carboned up. And now for my question.............

Are you aware of a method or material that will "soak" this carbon buildup away? I don't want to remove the head if I don't have too. I know that this style of diesel probably failed for just this reason..........

But I also know that there some Thermoil guys out there with a whole lot more experience than me so.......................whatcha' think....????????
Reply With Quote
Sponsored Links
Old 08-01-2005, 10:06:28 AM
KeithW's Avatar
KeithW KeithW is offline
Join Date: Jun 2005
Location: North Las Vegas, Nevada USA
Posts: 1,066
Thanks: 12
Thanked 200 Times in 145 Posts
Default Re: Thermoil Head and Cylinder Cleaning

The Auto Zone house brand carb cleaner in the yellow can seems pretty good at loosening up carbon. Are you sure it's carbon and not something else like a stuck valve or mouse nest? Not kidding about the mouse nest thing. Car collectors have had mice go through the entire exhaust system, past the open exhaust valve and build a nest in a cylinder.
Reply With Quote
Old 08-02-2005, 08:18:51 PM
Kenny Towne's Avatar
Kenny Towne Kenny Towne is offline
Join Date: Nov 2004
Location: Indiana
Posts: 23
Thanks: 0
Thanked 0 Times in 0 Posts
Default Re: Thermoil Head and Cylinder Cleaning

Keith has a point never know what might be on there. Does it feel like a "hard" stop or something with a little give (like a mouse nest). You might be able to remove the injector and cup and peek through the small opening into the cylinder with a mirror. IF you can get the cup out! Otherwise, the only ways to look in would be to remove the head or pull the piston. I'm not fond of pulling pistons out as it seems everytime I do, I make matters worse. Another couple things about squirting things like Gumout into a Thermoil.....firstly that liquid and dissolved stuff has to go somewhere. the valves are not on the bottom of the cylinder and as such not suitable for draining such goodies out. The other might be scary....Thermoils love aromatics like Gumout and WD40 and gasoline fumes and the like. If you get a load of that in there and crank it over with any just might light off when you least expect it. I believe there is a certain gentleman at Rough & Tumble who unintentionally launched the cup out of the injector with a little velocity in this manner. I know he frequents this page and he might be able to add some thoughts as well. He resurrected a Brantford recently and did an armload of work to get it in shape.
If you need a manual to take a peek at the following address, I have a Model "U" manual posted on my website, maybe it'll help a little.

Send me a picture or two of your beast, I'd like to add it to the web pages to build up the Thermoil library some more!

Hvids Reign Supreme!
Reply With Quote
Old 08-13-2005, 06:57:45 PM
MikeF MikeF is offline
Join Date: Aug 2005
Location: Wampum, Pennsylvania USA
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Default Re: Thermoil Head and Cylinder Cleaning

I agree with the other guys. I would remove the head.
This will allow you to do a complete inspection of valves,
seats, and the injector. I have a 3HP and all of the above
needed a good cleaning, they were carboned pretty bad.
As they mentioned, be careful with the wd40, ect. it will
definitly fire on fumes from such stuff. Hope this helps.
Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

F o r u m Jump

Similar Threads Chosen at Random
Thread Thread Starter F o r u m Replies Last Post
Cylinder head for Onan JB / JC JCarroll Onan Generators 2 08-28-2006 07:36:35 PM
REO cylinder head Mike S Small Air Cooled Gasoline Engines 0 05-25-2006 10:08:10 AM
Cleaning Head Mike Inglis Antique Engine Archives 2 03-16-2003 08:21:31 PM
Welding Cylinder Head Josh Welding Shop 12 12-07-2002 12:22:19 PM
Repairing cylinder head David Erb Antique Engine Archives 2 10-29-2000 10:28:04 AM

Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 09:44:13 PM.

Smokstak and Enginads site search!

All use is subject to our TERMS OF SERVICE
SMOKSTAK® is a Registered Trade Mark - A Community of Antique Engine Enthusiasts
Copyright © 2000 - 2016 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277