Jump to content

Nominations for Tractor of the Month
Garden Tractors and Parts on eBay



Photo
- - - - -

G14 engine rebuild


  • Please log in to reply
7 replies to this topic

#1 Nascar3244888 ONLINE  

Nascar3244888

    Tractorholic

  • Senior Member
  • Member No: 1218
  • 164 Thanks
  • 593 posts
  • Location: Douglassville, Pa.

Posted November 04, 2011 - 08:14 PM

Well aftergetting rid of all the bugs this summer by running Mr. Smokey( G14 ) I decidedit was time for rings in the old OH 140( 14 HP ) Tecumseh. Ive been taking lots of pictures and postedabout not knowing how to remove the rocker bottom cover( thanks for the helpagain guys!! ) I am going to post some of my most recent pics on the progress Ihave been making. I finally have ittotally torn down. If you guys rememberI was doing a rebuild on an Wisconsin S7D which was going to be my firstrebuild but after getting all the parts to do it, it kind of got pushed to theback of the shed so to speak. Anywaysthis is definitely going to be a start to FINISH rebuild!! I want to take you guys along for the ride andmaybe get a few pointers along the way.

As I said I didjust finish completely tearing apart the engine. I was able to get the compression rings offno problem but the oil ring broke in half. I was also able to use the compression ring to check the ring gap whichwas .024” Thepiston itself has no markings on it suggesting that it is anything other thanstandard bore. So, My first question is…..is .024” ring gapwithin specs??? If so just let me know whether a standard set of rings areneeded to re-ring the piston. Also, Ihave not yet honed the cylinder but it shouldn’t need much because it is reallyin nice shape with no finger nail feeling scores in the cylinder or piston andthere is no lip at the top of the cylinder either.

I have found aset including the piston wrist pin and clips for 65. or something plus shippingbut do I really need something like that since mine is fine??? I was hoping tomaybe just get away with a new set of rings and maybe a gasket set…Im actuallyhoping rays has a set of rings and a gasket set so I don’t have to buy anythingoff ebay. Well enough talking now…heressome pics….

Attached Thumbnails

  • 2011-11-04_20-09-35_593.jpg
  • 2011-11-04_20-14-29_280.jpg
  • 2011-11-04_20-09-40_730.jpg
  • 2011-11-04_20-09-19_906.jpg
  • 2011-11-04_20-09-29_304.jpg
  • 2011-11-04_20-14-33_520.jpg


#2 awol OFFLINE  

awol

    Tractorholic

  • Senior Member
  • -GTt Supporter-
  • Member No: 1576
  • 77 Thanks
  • 339 posts
  • Location: Smiths Falls Ontario Canada

Posted November 05, 2011 - 05:47 AM

Thanks Brad, for posting the pic's of your OH140 build.I will need to do the same to my smoker(H14)and will need all the help I can get:confuse:I will live with the smoke till spring as I need the H14 for the snow. I hope to see yours run without smoke soon:smile1:best of luck with you build.

#3 Bolens 1000 ONLINE  

Bolens 1000

    DR. Bolens

  • Staff Admin
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 7
  • 12,701 Thanks
  • 17,209 posts
  • Location: Western NY

Posted November 05, 2011 - 08:06 AM

Here's a manual, hope this helps with the specs :
With a gap of 0.24 you should be ok with a standard size ring set

Tecumseh cast iron 8 to 18hp engine manual - Manuals - Garden Tractor Talk - Forums

#4 Lovintractorin OFFLINE  

Lovintractorin

    Tinkerer

  • Senior Member
  • -GTt Supporter-
  • Member No: 4180
  • 159 Thanks
  • 603 posts
  • Location: Mostly in my Jeep

Posted November 05, 2011 - 08:13 AM

My Bolens 1253 has got the same problem. The HH120 smokes like a chimney but I'll just have to keep pouring oil into it until next year, cause similarly to awol, I need it for snow. Thanks for posting the pictures and I'll be watching this thread to get an idea of what I am gonna be getting myself into.

#5 DH1 ONLINE  

DH1

    Electric Tractors

  • Senior Member
  • -GTt Supporter-
  • Contributor
  • Member No: 62
  • 4,587 Thanks
  • 5,295 posts
  • Location: Markham Ontario Canada

Posted November 05, 2011 - 03:53 PM

Your best source for parts is>Tecumseh Engine Parts
  • awol and Lovintractorin have said thanks

#6 LPBolens ONLINE  

LPBolens

    Tractorholic

  • Senior Member
  • -GTt Supporter-
  • Contributor
  • Member No: 874
  • 1,176 Thanks
  • 882 posts
  • Location: North Central Illinois

Posted November 06, 2011 - 09:01 AM

According to the manual, the minimum ring end gap is 0.010"; the maximum is 0.020". Did you check the existing end gap at the top, middle and bottom of the piston travel in the cylinder? Don't forget that at cylinders wear, the least wear is usually at the top of the bore. As the piston travels up and down, the rod tries to angle the piston in its bore towards the mid point of the piston travel because of the crankshaft throw, so often the most wear is in the middle of the piston travel in the bore. As a result the bore can go oval in the middle of the piston travel area, leading to blowby. Note that the manual instructs you to use the inverted piston to push the ring down into the bore to make sure that the ring you are checking is square to the bore at each point.

If everything was fine with the piston and rings when you tore the engine apart, you would have to ask yourself why it would smoke.

#7 Nascar3244888 ONLINE  

Nascar3244888

    Tractorholic

  • Senior Member
  • Member No: 1218
  • 164 Thanks
  • 593 posts
  • Location: Douglassville, Pa.

Posted November 07, 2011 - 05:00 PM

According to the manual, the minimum ring end gap is 0.010"; the maximum is 0.020". Did you check the existing end gap at the top, middle and bottom of the piston travel in the cylinder? Don't forget that at cylinders wear, the least wear is usually at the top of the bore. As the piston travels up and down, the rod tries to angle the piston in its bore towards the mid point of the piston travel because of the crankshaft throw, so often the most wear is in the middle of the piston travel in the bore. As a result the bore can go oval in the middle of the piston travel area, leading to blowby. Note that the manual instructs you to use the inverted piston to push the ring down into the bore to make sure that the ring you are checking is square to the bore at each point.

If everything was fine with the piston and rings when you tore the engine apart, you would have to ask yourself why it would smoke.


Im not really sure why it would smoke, all I can say is that I did use the method you said above by using the piston to push the ring down to check the gap, I did this at the top, middle and toward the bottom of the stroke and It was slightly snugger in the middle and bottom than it was at the top but .024 was the reading at the top and it went in at the middle and bottom too but I could have most likely got a .023 to fit better. I will say that once the tractor would run a minute or two that the smoking would minimize drastically down to the point where it would only smoke slightly when you moved the throttle to high or low and then it would stop, it was just for that first minute or two it would really smoke. the previous owner used the tractor very very much since new so I figured the rings were going. Plus it needed to be torn apart anyway to fix where the thing leaks and just give it a general clean up. To me it seemed like the tractor still had tons of power even though it was smoking. I cant even tell where it was leaking there is so much caked on sludge on the outside I just couldnt tell. Does this engine have valve seals?? Maybe there bad...not sure...The piston wasnt really even that carboned up at all and the guy said it had be smoking for at least 10 years...

#8 LPBolens ONLINE  

LPBolens

    Tractorholic

  • Senior Member
  • -GTt Supporter-
  • Contributor
  • Member No: 874
  • 1,176 Thanks
  • 882 posts
  • Location: North Central Illinois

Posted November 07, 2011 - 06:57 PM

There are O-rings that go on the valve stem. These are included in a full gasket set.

Another possibility for smoking are worn valve guides, although the fact that the smoking seems to go away when the engine warms up, and that there is little carbon makes me think that the engine is in pretty good shape.




Top