An out of balance blade was one of the things I ruled out- two back up blades were put on- one freshly sharpened/balanced at the shop, and one brand new blade were tried, w/ no change in vibration. Muffler bolts are not the problem- the heads can be seen on the upper surface of the deck, and the ends/bolts are seen secure on the muffler plate bottomside. The 1st repair I noted from 2001 were described as replacing the 'lower seal bolts' on the receipt. The shop manager said there are 4 of them. In looking at the LB parts blowup on https://lookup2.toro.com/partdex/index.cfm?xCaller=lawnboy There are four bolts (part #314576-'40' on the diagram) These come up from the bottom of the crank, where there is a crankshaft end cover. The bolt threads pass up thru the top of the muffler plate, thru the lower crankcase seal, and into the lower part of the crankcase. I do not see nuts on the diagram, it is not clear where the ends of the bolts go. I am fairly sure these are the origin of the problem. That all said, QUESTION- I am wondering if the rod and piston are degraded by a bent crank? I should note I still have to perform Walt's 'wiggle' test as note in his original post to see if the crank is bent, or if we are just dealing w. loose lower crank bolts. Walt- can you clarify your statement- 'These engines routinely wore out the bottom bushing which is not a replacement item although several guys have bored them out and installed an "F" series engine needle bearing.' What is this bottom bushing? Is that integral to the crankshaft- and that is where the shaft has an hourglass shaped 'bulge'? Thanks again everyone!

When was the first globe or world map made? How the hell would they know which way is up? Just because it was drawn like that, dont make it correct! Just every Tom, D!ck and Harry got on the band wagon and spread there fowl lies! For the record, we dont drink Fosters. We export it to America so you dont have to drink your own cr@ppy beer! Same as you lot exporting Bud and a few others! lol Get yourself a 6 pack of Coopers Pale Ale! Now thats a beer! To get the right effect, you must drink it while standing on your head so you know what its like to be the right way up! After a 6 pack, it really wont matter what the globe looks like! lol

am leonard? whenever I get bored and want a particular type of tool, I find websites for regional trade shows and browse/search the exhibitor listings. found some stuff I didn't know existed...and after two decades attending trade shows, that takes some doing ie, farwest show, mid am trade show, minnesota green expo, new england grows, mid states hort expo.

Thank you to all of you for your input. Tomhoffman, the topography (hillside, several draws) is not condusive to plowing, and I do not want to disturb the soil (the property has been resting since 1962 and there is very good biological activity in the soil). It will take hard work to exhaust the Himalayan blackberry through mowing, but it can be done within 4-5 years. And since I'd have to mow anyway, whether grass alone or grass and blackberry... it makes sense to keep mowing. Sergeant, thank you for the link to the 4105. Definitely looks like something I should consider, and it also confirms what Corvetteguy and Gzec recommended. Thank you for the info on the MSRP. Turnage, the grass that I hope to have out-compete the blackberry (and some Poison oak and various thistles) is Blue wild rye (Elymus glaucus) and Western fescue (Festuca occidentalis). They do grow tall and my stand will be seeded for a dense cover, in order to out-compete the weeds. Sounds like I'll need at least 30 hp, if not 40-45. Johninmd, I do not have a four wheeler that could drag a mower. Johntommybob, yes this is an orchard in the making. I believe that once we get rid of the blackberry and other invasive plants, we'll have to deal only with grass, and we'll cut it repeatedly so it doesn't grow too tall and does not compete with the young trees (for water and nutrients). At that point in time a zero turn might do the job, especially the ATV version (because the topography on my site is pretty hilly, with several draws and a couple steeper slopes). Thanks again