# John Deere TRS26 bad blowby, rebuild questions



## turbo6justin (Dec 13, 2011)

Hello all, new guy here, it looks like a great forum. Hopefully I won't need to visit too often though. I have a John Deere TRS26 that was passed onto me from my father. I have run it for 2 years but it has been a struggle. Last year I had to use the fuel cut off to regulate fuel to the carb because of a sinking fuel float. Anyway even last year there was a lot of oil/blowby coming out of the breather tube. This year it is no better and I mean there is a lot of oil coming out. If the oll fill cap is left untightened it will jump up and down as you slowly pull on the pull cord. Compression is obviousely getting where it shouldn't be. My first thought was rings and I am still leaning that direction. I was reading on here about the Tecumseh exhaust valve carbon issues but am not sure I buy that in this situation.

Does anyone think I am in the right ballpark or way off base? I have rebuilt 6-8 car engines in my life but never a snowblower. Is there anything I need to know. I see from the diagrams there are no rod bearings which is a little weird any other suprises?

I have a ton of questions hopefully I can get a few answers.

1)Without tearing it down I am not sure what the cylinder looks like but is this the same as a car where IF it needs to be opened up .010 it also requires a new piston? Or can I use .010 rings on the old piston? There are relatively low hours on this machine so I might only have to hone the crosshatch back in.

2)Approx torque specs for the rod bolt and head bolt? The others I can guesstimate but these are pretty critical.

3) ring gap? If that is indeed my problem.

4) Valve lash? I will clean up the valves as best as I can when I am in there of course.

5) Any other suprises?

Many thanks in advance, as with a lot of people right now money is very tight and I am trying to do this as efficiently as possible.

P.S. Any reason why the standard ring set is not available by itself only as a set including the piston itself? The .010 and .020 are abailable rings only.


----------



## Shryp (Jan 1, 2011)

Is this a Tecumseh L-Head or one of the newer overhead valve engines?
Here are the complicated specs for the l-healds, detailed table of all torque and gaps at the end:
http://www.allotment.org.uk/assets/rotovator/Tecumseh-Engine-Manual.pdf

For a more simple explanation of these engines look here:
donyboy73's Channel - YouTube

He has lots of videos of tear downs, just search for tecumseh.

I have never fully rebuilt one so can't answer your other questions. It is my understanding that you should use an oversize piston and rings if you bore it out.

Some people that know better could get you better answers with the engine numbers stamped on to the top of the engine.


----------



## td5771 (Feb 21, 2011)

This is the super hack/budget answer. I have used it in the past and it did work but not every time. If you are going to tear down the engine it is worth a shot.

Coming from an old diesel engine guru......while the engine is running full tilt, pour boraxo powdered hand soap, yes boraxo or zud or similar into the carb intake. it will run terrible for a while but pour in plenty but not enough to make it stall. then keep it running until it clears up. it scuffs the cylinders and rings, kind of re seating them.

like i said ......the hack quickie fix.

or a decent budget fix is measure the bore, if it is close to stock, home it with a cheap honing tool and put new rings in. all you would need is rings, a gasket kit for the engine and the honing tool (buy or rent).


----------



## turbo6justin (Dec 13, 2011)

Thanks for the quick answers the engine number is HM80-155392P and I believe it would be a little older. I will start looking at the diagrams and should be able to tell the difference but I am guessing it is older.

Funny you should mention the Borax idea. I used that once on an 'ole 242 straight six to get it about 150 miles to where I could pull and rebuild the engine. It worked pretty well. On that particular engine once it got hot it was like opening the drain plug, cold it was 'alright'. So it was either a very long drive back or... It worked pretty well actually. Now I use a trailer.

I should have a honing tool that would work not sure if it will go down to 3.125 dia but I can also borrow one if not. That was my thought, get it opened up and measure. If it is close run standard diameter, if not then I have a few more problems.


----------



## turbo6justin (Dec 13, 2011)

Holy cow! That PDF is gold.

Thanks Shryp.


----------



## twofishy4u (Dec 6, 2011)

if you didn't fix the fuel issue that could be the whole problem. Gas in the oil thins it greatly. Also it would be much easier and maybe cheaper to buy a good used engine. By the time you do a piston, rod, machine work, valve relap....it's gonna cost some $$$ and a lot of time. I definately would do a rod and regrind if it were mine along with a piston and rings. JFYI that isn't an actual Deere made blower.


----------



## HCBPH (Mar 8, 2011)

turbo6justin said:


> I should have a honing tool that would work not sure if it will go down to 3.125 dia but I can also borrow one if not. That was my thought, get it opened up and measure. If it is close run standard diameter, if not then I have a few more problems.


Just a FYI, Harbor Freight does have a couple of hones that should go down far enough for you. For the price, I consider them pretty much throw-aways. I have in fact used one once, wasn't in an engine (had to clean up the inside of some 3" pipe for a project) but it did work out ok for what I used it on. Might be worth a look if you just need something for a one time project.

Let us know how it turns out.


----------



## turbo6justin (Dec 13, 2011)

Yes I had considered the cylinder wash down effect and the thinning of the oil. That is the reason I made sure to get the Carb working right before looking into the engine. 

I am also wondering if because the fuel issue was present for a while if that didn't glaze the cylinder to the point it is at now where the rings are not sealing well. Oddly the oil was not all that contaminated with fuel and of course there is new oil in there now. I am starting to think if I do open it up and start taking measurements I may find things a lot closer to spec than expected (cylinder diameter and ring gap). If that is the case I will probably just take a bead hone, scratch up the wall a little, clean it up real good, and put it back together.

I am a little curious why you would suggest replacing the rod? I am considering this a piston/ring issue not a crank/rod issue. As far as I can tell it is not making any knocking noises. I'll clean the valves of carbon and other gunk but beyond that I was going to leave them alone.


----------



## twofishy4u (Dec 6, 2011)

just this year I have had 2 dead tecumsehs both had oil in them, rods let loose and went through block. For $30 it is worth replacing. Tewarehouse.com has good prices on rods, rings, pistons, whatever just make sure you have a part # before you head there, there search engine is terrible. Valves...I've had good engines 90psi compression and after a valve job I can get over 120psi. They aren't that hard to relap and gap set.


----------

