Does the Tecumseh LAV50 62073C have a compression release?

baymee(LehighValleyPA)March 3, 2013

This engine pulls really hard with the plug in. I took the plug out and it pulls reasonable. I pulled the head to see if it was all carboned up and it wasn't.

Looking at a cam on a parts schematic doesn't show anything and moving the flywheel manually doesn't make the exhaust or intake valve 'bump' at any point in the travel.

This is a points model.

This post was edited by baymee on Sun, Mar 3, 13 at 17:33

Thank you for reporting this comment. Undo
tomplum

It should have. Tecumseh did use different versions of compression releases tho. Always on the exhaust if I'm reasonably accurate. I would think the little lever, spring style on the back of the gear is what this one would have. I assume the blade is on, hub locked to the crank etc.?

    Bookmark   March 5, 2013 at 12:05AM
Thank you for reporting this comment. Undo
baymee(LehighValleyPA)

It's on an old Sears rototiller. Assuming it has one, wouldn't there be a slight lift on the exhaust valve?

    Bookmark   March 5, 2013 at 6:10AM
Thank you for reporting this comment. Undo
tomplum

You could pull the breather and insert a feeler gauge at the exhaust tappet to act in place of the missing bump. How does it crank then/

    Bookmark   March 7, 2013 at 11:09PM
Thank you for reporting this comment. Undo
baymee(LehighValleyPA)

Hmmmm. Interesting idea. Why does Tecumseh have to put the breather behind the carburetor? There is so much room on the other side of the block. :)

Don't valves normally close the gap with age, as they sink into the block? Or does the end of the stem wear off faster?

    Bookmark   March 8, 2013 at 5:38AM
Thank you for reporting this comment. Undo
tomplum

You may be able to snake it out once you remove the manifold bolts. Maybe even able to try the manual compression release test if there is room. There are several theories on metal expansion to be put to the test here. I say time to do your homework, measure the gap and post the results :) Then we will know for sure.

    Bookmark   March 8, 2013 at 11:39PM
Thank you for reporting this comment. Undo
baymee(LehighValleyPA)

You were correct. The gap was too big. I reduced it to .004 and the exhaust valve opens now. Now I have another problem. I ground too much off the stem trying to compensate for the deeper seat cut. I had another exhaust valve from a 5HP and somehow I screwed that one up too.

Having no other valve, I migged some length to the valve. I wonder how long that material will last??? It's on an old rototiller that probably doesn't get used that much.

Good news is that it's now a perfect .004

This post was edited by baymee on Mon, Mar 25, 13 at 19:52

    Bookmark   March 25, 2013 at 7:51PM
Thank you for reporting this comment. Undo
tomplum

Quite ingenious! Where are those seat cutters when you need them.... :)

    Bookmark   March 28, 2013 at 11:27AM
Thank you for reporting this comment. Undo
baymee(LehighValleyPA)

That's what started this mess. I cut slowly and couldn't close the gap. Then I got more aggressive and all of a sudden,,,,,oops. Then I couldn't open the gap after several tries. I got more aggressive on the stem and all of a sudden.....oops. And a second valve.....same thing.

I got to thinking about the mig welded stem end. I believe these valves are stellite, so mig steel is no match.

Found some NOS on ebay and bought two new valves. This time I will grind more carefully. But I have the second valve just in case. :)

    Bookmark   March 28, 2013 at 2:43PM
Thank you for reporting this comment. Undo
tomplum

Oh, I meant like a Neway seat cutter that removes the material from the seat in the block. Will stretch a valve everytime!

    Bookmark   March 29, 2013 at 10:45PM
Thank you for reporting this comment. Undo
baymee(LehighValleyPA)

I used the Neway first. I guess that got out of control too.

    Bookmark   March 30, 2013 at 7:02AM
Thank you for reporting this comment. Undo
baymee(LehighValleyPA)

Got the new exhaust valve and got the clearance at .008. The motor starts like a charm. Learning experience for me.

    Bookmark   April 3, 2013 at 7:43PM
Thank you for reporting this comment. Undo
the_0utsider

"I ground too much off the stem..."

I did that with my briggs.

My valve stretched so i ground it down but too much. I slipped in some sheet metal with the tabs folded over so it stays in place. 3 years and still running.

Poor mans alternative from starting over.

    Bookmark   April 9, 2013 at 12:04AM
Sign Up to comment
More Discussions
Bad ignition coil magneto on Tecumseh
Is there a more economical solution to replacing a...
don_v
Bosch Rotak 36 Rotary Lawnmower
I am currently studying for a Horticulture qualification...
jen9716599
Tru-cut Reel Clutch Adjustment
I've owned this guy since new (1979). Beyond normal...
runner70
I have a Tecumseh 5hp egine no spark
I measure the ohms from the following. I placed one...
Nutty1269
Craftsman ZTS 7500
Going to look at a used one of these tomorrow. Anything...
radlee30458
© 2015 Houzz Inc. Houzz® The new way to design your home™