Splitter motor is back together

My splitter motor quit on me the other month and I parked it next to the shed until I had time to mess with it. I went out today to split wood and it wouldn't start! I tried everything and nothing worked. Then the starter cord broke and I had to rewind the dang spring..... Yup, never fixed it before the snow.

My wife came out and saw that I was ready to shoot the motor and decided to build a shelter out of straw for me so I could be out of the wind. She did a darn good job. I sat there messing with it for a while and was getting a little upset with it so she asked if I would like to unbolt the whole motor and work on it in the kitchen. Of course I did just that. I spilled gas all over the table and a half quart of used motor oil on my pants, but I got it apart and found a bad head gasket, a bad-from-the-factory cam, and some terrible valve shrouding.

I made new head and crankcase cover gaskets from the old standby, cereal boxes. They work great, you know. I reground the cam, since the intake valve never really closed all the way. The valve timing was also very much not where it should be even though the timing marks lined up, so this was remedied at the same time. The factory "finish" on the cam looked like someone ground it with a very coarse angle grinder. It is now very shiny and smooth.

I had to get the dremel out since the head was off. I unshrouded the valves and reshaped the transition going into the cylinder. I am very happy with he way it turned out. Sorry, no pics.

I set the ignition gap fairly tight because the spark was a little weak when it was outside. Now you can hear the spark when you rotate the crank by hand and it is blue instead of orange.

I put everything back together and torqued the head bolts to 180 inch lbs for good measure. The motor almost flew across the kitchen when I pulled the rope to test the compression. WOW! I think the thin head gasket and valve that now closes helped it some. I put oil in it and gave it a tug. It roared to life and bounced half way across the floor as I tried to catch it. I don't think it has ever run this good. I am very eager to put it back into service. It has been running for many, many years with a valve that never closed all the way. There was an extra bump on the intake lobe that kept the valve open just enough. I was amazed that the motor ran as well as it did all these years. That's a briggs for ya.

What, you've never reground a cam? It's not that hard. Why do people talk about this stuff as if it is rocket science? It is a small briggs and stratton on a homemade splitter.
I have been using cereal box gaskets on small engines for years and they last just as long as a factory gasket. My dad had an old johnson that ran with cereal box head gaskets for close to 20 years. Regrinding the cam was the ONLY way to fix the valve problem because it was the cam that was keeping the valve open, so yes, it was the right way to fix it. The intake valve only closed when the cylinder was almost at the top of the compression stroke, so most of the mix was blown back into the carb. I know this was happening because the filter was always soaked and it sounded weird.

The cam had a boo-boo from the factory. I ground off the boo-boo and it works. I don't know how thew motor ever ran with the valve open for most of the compression stroke, but it obviously did and did so for many years. I cannot say what kept it running. I imagine when the head gasket blew, it released whatever compression it may have had and it was dead in the water. It runs great now and has plenty of compression.

razerface said:

When valve jobs are done,,if they replace the valves with new ones, or reseat them,,,and if they do not have the correct clearance between them and the cam,(which lets them close),,,they grind down the valve stem or the lifter,,,not the cam. Grinding on the cam would change the lift or duration of the cam,,making it worse.

Click to expand...

The duration was way too long. The tappet would ride down the back of the lobe and then continue to ride on a bump that should not have been there. That bump is what was removed so the valve could close just after BDC, instead of just before TDC. There is no more gas shooting back out into the air filter and it starts a lot easier. It always sounded like the valves were floating, but the springs were like new. Removing the bump on the cam fixed it.

This is what it looked like before.