Rebuilding a Snowblower Engine

I get stir crazy over the winter and as a gear-head grease monkey need something to wrench on So I figured I share with you my little project for the next couple of days.

Modding the Prius is fun and all but I need to get DIRTY! hehe.

I found a vintage Bolens 5hp 24" snowblower on craigslist for $75 OBO with a "bad engine" and the seller accepted my offer of $50 to take it off his hands. Hmmm... challenge accepted!


I got it home and looked it over... its in great shape overall. The transmission is still smooth, everything is intact and very little rust/wear. It was probably rarely used, based on the looks of the auger and housing.

Put some gas in it, changed the oil and it started right up! Engine was quiet. For a minute I thought "COOL! The seller had no idea what he was talking about, this engines fine!" ... that is, until I saw the crankshaft PTO walking around in its journal and spewing oil everywhere.

Ok ok...Chris, find your happy spot. A few choice words came out of my mouth as I was hoping for an easier fix. Oh well...

Get the engine off the machine, and the side cover off the side of the engine. Ah ha:
The crankshaft journal all gouged and chewed up


The crankshaft galled


NOW I see why the seller deemed the engine trashed. The engine had probably been run low on oil or the incorrect grade, and the crankshaft suffered oil starvation. Funny, the camshaft and the cylinder itself looks fine. Im going to be mic'ing everything before I put it back together so Ill know if the camshaft and cylinder/connecting rod suffered a similar fate. Going to have to ask an expert rebuilder why so.

Anyways, I will update this in the next week or so with my progress. I was able to find the side cover and the crankshaft - believe it or not, this series of motor was very popular and manufactured by Tecumseh for 25 years, used on snow machines, motor bikes, yard equipment, etc. The parts network is very strong (bonus!).

Wish me luck

 

Thanks! I added it to my bookmarks.

I was able to get a new side cover for $18 shipped. The gasket was about $4. Im now chasing down a crankshaft. Found one for $30+ $15 shipping.

I priced out a new china motor at Harbor Freight ($119) but it doesnt have electric start like mine does, so that would be $80 more.

Im still ahead rebuilding the current engine

 

Yeah... lets see though when I start really tearing into it. I need to take the cylinder head off to check the cylinder walls for scoring and clearances. Also I need to check the connecting rod for same. This could get either a.) to expensive/cost ineffective to rebuild or b.) simple job by just having to replace the crankshaft and side bearing cover.

If it needs more than the crank & cover, if the cost exceeds $100, I will stop and go buy a new engine from harbor freight. I dont want to do that, I want to keep the machine original. But the economics of this job will dictate the machines future powerplant.