John Deere L100 Lawn Tractor - Intake push rod not moving

[StarTech]

peening only works for a little while once the aluminum has softened from getting hot.

Well I have been cutting 4 acres of 6" or greater for two years now without a problem. I actually some grass waist high with the same engine but that usually a half acre at a time or one tank of fuel whichever I feel like doing.

 

[farmchick]

He probably reuse the current as they do come loose at times without breaking. Here is how a replacement is install locally without a machine shop. IF new seat then it will cutting seating area for the valve to specs.
View attachment 61070
It is the same thing I did on my personal 330000 engine when the exhaust seat came loose.

That is exactly what I did, Star Tech! Did your repair hold up well?

 

[StarTech]

That is exactly what I did, Star Tech! Did your repair hold up well?

So it has held for two years.

 

[farmchick]

My L100 is running again. It startrs great and runs for about a minute before it begins smoking heavily. Grey smoke from exhaust area. But runs fine.

Model 31F70
Type 01121E1

History...I repaired the exhaust valve seat/guide, lapped the valve, replaced the valve seal but didn't get it fully seated. It started fine but was smoking heavily just as it is now. Replaced the valve seal. New head gasket. Didn't get the intake rod seated properly. Fixed that. Now it has still this smoking problem which I had assumed was caused by the valve seal that broke free from not having it properly seated.

Is this just burning rich which might have caused the heavy carbon deposits in the engine and possibly the valve seat failure? And if it is, how do I find the adjustment screw for the rich/lean adjustment?

The valve cover is leaking slightly. The gasket is visibly worn and I will replace it asap.

Thoughts?

 

[farmchick]

 

[sgkent]

Be as arrogant as you want. I worked in a machine shop. I've seen the effects of your home grown peening. As I said, it lasts a little while then one day bang the seat cocks after the aluminum gets hot, the valve head snaps off, and destroys the rest of the engine. If you are Ok with that then there is no harm. if you are not Ok with that then the head or engine, wherever the seat is needs to be disassembled, cleaned, heated, a new interference seat put in cold, stake, and then let the head shrink around it getting the proper crush, cut new angles. That will last as long or longer than the original.

Or catch it before it is loose and stake the aluminum over it with a flat punch.

 

[Hammermechanicman]

Peening in the valve seat is an approved fix and shown in most Briggs service manuals. Over the last 20 years i have done a bunch and have only had one fail on a 3.5hp engine and i knew that one was iffy when i did it. On engines where the original seat is slightly below the surrounding aluminum peening works fine. On ones where the seat is level with the aluminum i don't try to fix a loose seat.