Sixchows,
First, I would like to thank you for all the information you have posted on the forum - the only resources we have as obsolete tractor owners is eachother - and you've been spectacular.
I am new to the forum - saw someone post the link on the Bolens Tractors Club website on Yahoo and thought I'd give this site a look.
I am the owner of a 1975 G10, model 1055. It has a Tecusmeh HH100 engine in it. My father purchased it in 1978 from a widow and the tractor had very little hours on it. After over 3,000 hours put on it from cutting 15 - 1/2 acre lots over 12 years (as a business), plus snow removal through the years - in 1995 it started smoking. Ran it until 2001, and then had it sleeved back to standard because oversize parts were in short supply, and I figured at least .010 over would be available for the next 5-10 years.
Anyway, I am one proud owner of a Tecumseh HH100 that has had fabulous performance. In 1994, the stator went out and at that time it was available - so I replaced it. Other than that, change the oil religiously at 50 hours and they will run forever. After the 2001 rebuild, I currently have 110 hours on it since, and it runs like a champ. I now till with it, plow snow with it, plow my garden with it, mow, use a snowblower, and aerate. I give the engine 4 stars, and I have to based on my experience. Tecumseh has earned itself a bad reputation with its lower line model engines(H series, verticals, HMs, etc.), and rightfully so - but the HH100 and HH120 are horses if they are maintained. The common gripe about the OHV engines were the valve adjustments and the seals going bad in the heads.
HH means "Heavy Horizontal" - meaning all cast iron. They are no longer in production. The solid state ignition is great, however any electronic circuit is bound to wear out sometime, which is the con to SS ignition versus points. My gripe against Tecumseh is that they dropped all support for these engines completely all at once - whereas at least Kohler, Briggs and Wisconsin to some degree have still supported their old workhorses. The phase out of the cast iron engine is a result of cost (cast iron vs. cast aluminum) and its inability to pass EPA emission standards - forcing manufacturers to go to aluminum block/cast iron sleeve overhead valve engines. Unfortunately, what people do not see is the lack of torque that the new engines have. Grab a torque curve online of a B&S 10 hp engine and look at the curve for and HH100 or even a Wisconsin TRA-10D, and you'll see the difference - they are worlds apart.
My Tecumseh has worked wonders - I love it to death. In my book, Wisconsin was the best until they hit financial trouble (I think they hit Chapter 11) and lost all the contracts. Best on the market today is Kohler, in my opinion. They have been able to maintain their durability and overall torque and power. Honda and Briggs are good engines as well. Today, Tecumseh would be at the bottom of my list. They've gone through an internal overhaul and after years of poor performance have lost their credibility with a lot of users, not to mention upset people like me that they could have kept supporting at least from a 'minor parts' availability standpoint.
My 2 cents worth anyway... Have a good one!
peachfuzz