Sunday, March 8, 2015

Murray 11/36 engine

Saturday, March 7, 2015

Model 252707
25 ci
series 2
7 vertical crankshaft
0 plain bearing non flange
7 electric starter with alternator

Code 8109211 = Sept  9th, 1981


Today was in the 60s so I took the opportunity to check on the condition of the engine.   Turning the screen by hand showed good compression.  So I hooked up the jumpers and turned it over after spraying a bit of car cleaner in the intake, the carb is off.  

It fired and ran for a second or so.  On the second attempt the engine would not turn over. I had not heard any clunking so I figured it could be something with the starter.  Dirty ones often fail to retract the gear.  So I took off the shroud and that was the case.  

It was amazing how badly the fins are blocked on this engine.  I am debating if I should pull the engine apart and clean it inside too.  That would also give me a chance to see what shape it was in but I can generally do that with just pulling the head and checking the cylinder and valves.  I think I will just do a series of oil changes.

I should get this thing to the car wash but need to put a muffler and carb on to keep the water out.




The starter came off easy enough and it turns but hard, needs cleaning.   The only part I don't like about fixing starters is punching out that pin.






Sunday, March 8, 2015


Linkages
Wiring near linkages
This one has the cone washer.
Soaking the nut with PB Blaster

Took the engine off and visited the car wash.  I did not get all the crud but at least it is to where I car to work with it.   One of the linkage rods may have gotten lost along the way.

Used the air chisel to get the drive pulley off.  The lower pulley (mower drive) was trashed when the previous owner loaded it on my trailer with a fork lift.

The flywheel did not want to come so I am soaking it in PB Blaster for a while.

Monday, March 9, 2015

After soaking a day with PB Blaster the flywheel did not come off with the air chisel so I used a large HF 3 jaw wheel puller and the 1/2 air impact wrench on setting 2.

Today I pulled the engine apart.  The rod journal is out of round by .004, 1.2525 x 1.2485.  Reject size is 1.2470 so it squeaked buy on that one.

The cylinder has significant scoring but the engine did show good compression cold.  No way to know that it will do when it warms up without trying it.  I am torn between just putting it back together and getting a pair or chrome rings for $20.

I don't know how much the scoring will effect compression it may be that the engine is good enough for making a tractor move but nothing you would want to put into service.

Tuesday, March 10, 2015

The plan is to reassemble it.


Did not remove the valves, worked around them with a wire brush and lifted them to was the crud out from around them.  I have done better cleaning jobs but the insides are clean.

The head gasket form the DYT4000 came today from amazon.  It is bent and even broken which is not all bad as it does not tempt me to stop with this engine.

I was tearing out my hair trying to find where I left the flywheel screen, nut and washer.  Then I recalled I took some photos but the one I was thinking of was a closeup with no way to tell where it was taken.  The one next to it was this which nailed it.

Still missing a few bits.











Wednesday, March 11, 2015



The last few bits came together today.  Grabbed a starter off another engine.  Found the ditty that holds the oil filler tube in on the ground next to the tractor.

Removed the hood.  Took a wire brush after the oil and dirt caked to the engine mounting area.





The engine is bolted to the frame but nothing is hooked up.   I used a stick to hold the throttle open and ran jumper cables to the starter.

On the first attempt I tried carb cleaner with no joy.  I changed to a fresh spark plug and used a dribble of two cycle gas.  It ran while the gas lasted.  I made a short video of that.  This is the first try after stripping down the engine although I say 2nd in the video.


<missing video>


If I get a chance to work on this tomorrow it will be the moment of truth.  Will it run without smogging mosquitoes?

I did not tighten the flywheel to the full 65 foot lbs of torque.  I do not trust the HF to go that high and the CDI does not go that high.

This carb was cleaned and used on the little MTD that I scrapped so it should still be in working order.  Just need to move the choke to the back side by swapping the choke rod with the one from the original rusted carb.

The original air cleaner on this engine is a foam filter setup.  I may switch it to a paper element filter from one of the other engines.  Maybe the same setup used by go-putz.

If I can't get a transaxle working for this tractor the engine will go to go-putz at least till I get its 13HP rebuilt or replaced.

Thursday, March 12, 2015

Installed gas tank shutoff and filter.  I opted to do this because even if I move this engine to go-putz for a while I can always use this for a test stand.

My thinking is that by putting this motor on go-putz I can more easily evaluate it.  If it is good and the rest of the tractor comes together I will move it back.  The plan is to run in on the tractor for a few hours to see what happens.  If it is still good move it to go-putz where it can get a workout.  Go-putz uses an on-engine gas tank so I will not have to take any of the fuel line bits off the murray.

It got down near freezing last night and the oil in the engine was too stiff for it to turn over.  I put the battery charger on the battery and will wait an hour or two while the engine warms in the sun.  It is in the mid 60s but the tractor is on the west side of the shop where there is AM shade.

Got it running for a minute but did not want to do more then that without an air cleaner.  What a hassle.   The go-putz style do not fit because these are 1 piece carbs.

The foam ones are all worn out #535.  The oval paper filter is dirty #445 and there is a spacer gasket #872 that has died.   The green part is listed as a spacer but shown as a gasket.

I am trying to clean the paper filter in the ultrasonic with tide.  We used to clean paper tractor filters with a special detergent so maybe this will work.

It seems to run good.  No smoke that I can see.  Just 1 puff when I started it.  Made a bit of a video and will post it when it uploads.

Still missing both the rods from the throttle to the governor and the governor to the carb.   If I move this engine to go-putz I will be using the setup of that engine and will have some time to find replacements.

Wonder if the alternator is working?

<missing video>