I have some questions for some of the Briggs & Stratton experts. First of all, I am not a small engine tech by trade, nor do I claim to me an expert. I am however very mechanically adept and have, over the years, made many repairs both major and minor to both large and small engines.

I have a B&S 31c707-230-e1, which became harder and harder to get started. When it did start, it sometimes ran a little rough, used a little oil and occasionally would belch a huge cloud of white smoke when I turned hard left. Like most people these days I�m on a tight budget, with no funds for major parts & repairs, so I decided to tear it down and see what I had. I had already checked the valve lash.

When I got the sump off I found the remains of the compression release mechanism in about a dozen small pieces, the oil slinger arm was twisted and the slinger teeth were badly chewed up. I decided my best option was to check around see if I could find a good used slinger and camshaft. My camshaft part number has been updated to "790400". I found a used camshaft out of a 287707-0220-01. It�s part number has also been updated to "790400", so I ordered it in, the price was right. When I got it, it was more robust that my original. My original cam gear had the "four spokes" rather than being solid and is slightly thinner that the replacement. The thicker cam gear caused problems because my timing gear has a flange on one side which kept the cam teeth from fully seating, which would not allow the sump to go on. There was a small bevel on the new cam gear but not enough to clear the timing gear flange. The B&S manual shows both type cams but makes no mention as to the differences. At this point I had nothing to loose, so I ground the bevel down so the gear face was aprox the same thickness as the original. This did allow it to fully seat, with a tiny bit of free play to prevent binding. The sump went on fine and manually rotating the flywheel multiple times didn�t indicate any binding or interference. The motor cranked up fine and I cut the yard for about 1 � hours with no problems. It still used a little oil but not much and no visible smoke.

Did I just fubar my part number ID�s? I did notice in the book that all the pictures of the timing gear show a straight cut gear rather than a gear with a flange on one side. Is there anything I should be looking out for with the heaver camshaft? Is it common for the compression release mechanism to explode like this?