I was out of town a couple of days and haven't been able to respond. Thanks for your response. I tried to be very careful not to turn or move anything. I did not check the timing marks when I put the cover back on, I only focused on getting the plastic governor gear meshed properly. I don't even know where the timing marks are. Considering that it won't even try to start, gets a good spark, and after pulling the cord numerous times gas will be visible in the carb cover around the choke plate, along with an occasional backfire, it does sound like the timing is off. Do you have any advice on setting the timing or maybe a website that might help? Obviously, I'm not an expert mechanic and hate to remove the engine again, but it looks like that's where I'm headed. Thanks again.

@andyma Looks like my connecting rod won't arrive until some time next week so it may be a while before I can begin to assemble. I am getting more and more frustrated with the lack of information from the manuals and doing searches on Google. I only have one shot of getting this right since there are no replacement engines or shortblocks for this Ariens ST7524 blower. Reviewing everything again I see another potential issue which is confusing. If you look at the manual(figure 33 in original post), it states the marks on the connecting rod must align and face out. Simple enough, but if you look at the oiler assembly in that drawing, the concave side of the oiler is facing up. Now picture in your mind, the flywheel rotation is clockwise, in that direction the oiler would NOT be scooping up the oil as the design indicates, but pushing it to the camshaft side, rather than upwards to the piston cylinder. I hope that someone with experience will reply to this post and hopefully provide an answer before I assemble. You probably have the manual, but if not below is a link that you can download the Tecumseh L Head service manual. I hope it can answer your questions but I doubt it will. http://www.allotment.org.uk/assets/rotovator/Tecumseh-Engine-Manual.pdf

We have an Ariens snowblower with a Tecumseh engine, and this unit has had an uneven idle since it was brand new. However, it starts on the first pull, even in the winter, and it settles down and works well when it is loaded. The manufacturers of small engines have been trying to reduce emissions since the 1970's, and they are all going to carburetors that run on the lean side, compared to equipment built before. Given that this engine is 17 HP, it likely has two cylinders, and there is a possibility that one of the cylinders runs a bit more lean than the other. This would result in an uneven idle. Cleaning the carburetor should help, but you might never succeed in getting it to idle as smooth as a fuel-injected car.

We purchased a Gravely Z252 commercial mower with a 24 hp Kohler mower in 2006 figuring it would be the last mower we would ever buy. A few weeks ago, while my wife was mowing she noticed the (650 hour in 12 years; 50 hour annual use) commercial engine sounded "funny" . When I pulled the oil dip stick it was dry. My wife commented there was no puddle of oil under where the mower is parked. Consulting the business from which we purchased the mower we learned that a significant number of the mowers purchased around the time we bought ours had catastrophic oil loss and "blew" engines when the inadequate Kohler head gasket failed. Supposedly, Kohler has redesigned its head gaskets with a metal rim on the gasket like auto engine gaskets. The gasket on our 2006 mower had no metal rim. I asked the business from which we purchased our mower why Kohler didn't send out an advisory to be vigilant in monitoring oil levels or even offered a replacement with the newly engineered gasket. Apparently, the business was aware of the gasket problem but neither they nor Gravely alerted us to the potential failure of the poorly designed gasket on our $10,000 Gravely commercial mower which was only used to mow around our home. I bet commercial mowers have 50 or more hours put on them weekly during grass cutting season. I realize the mower's oil level should have been checked before every start. However, my wife who loves to mow probably would not have taken advice from me. Had Gravely, Kohler or the business from which we purchased the mower had alerted us, my wife would have probably heeded their advice. During an election year, politicians are exceptionally responsive to constituents needs. I plan to craft a letter to Maryland's Governor, Comptroller and Attorney General. Depending on their response to my letter, there is still the option to sue Kohler and Gravely in Maryland Small Claims court. Incidentally, our new Kohler Command Pro CV742 25hp engine cost over $3400.00 installed. The upper limit for small claims lawsuits in Maryland is $5,000.00. Even if a company is headquartered outside MD, it is subject to suit it if it sells its products in MD. I will let you know how things turn out. Yes my wife is religiously checking the oil in our new $3400.00 Kohler engine. Thanks, Centreville Bill