Rebuilding a Snowblower Engine (Tecumseh 5hp)

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Moderators, please accept my apologies if this is the wrong place to post this and move if necessary.

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.

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 the tank, changed the oil (old stuff was nasty) 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 any damage. Going to have to ask a local expert rebuilder for their opinions as well.

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!).

I will keep the forum posted of my progress and hope to get this bad boy running in time for the next snow!

Wish me luck!

 

[lars11]

Great I bought à Stiga ( rebranded bolens 524) to rebuild à fel weeks ago. Will be interesting!

 

[HerrStig]

How much is a five HP Chonda?

 

[2oldtommy]

That design looks like my old Ariens 5HP from the '70's.Although Tecumseh is out of business, there are a multitude of parts available. The plastic gas tank would put it in the late 70's IMO. And yes , a Chonda engine is a bolt in replacement. A problem that you run into is a different shaft dimension IIRC. Google "Ariens sno throw" and you may find the site that details the step by step replacement.FWIW---Oldtommy

 

[Kestas]

Is this the engine with two counterrotating shafts (and pulleys) on the outside?

 

[2oldtommy]

Following up my previous post, Tha manuel for the Ariens is at http://apache.ariens.com/manuels/prm-10000.pdf This offers part numbers as well as a wealth of info on this old sno blower. FWIW--Oldtommy

 

[[email protected]]

Originally Posted By: HerrStig
How much is a five HP Chonda?


Does the Honda come with electric start? Its one of my dealbreakers. I really dont want to sink $400+ into this 35 year old machine, even with it being in good shape.

Originally Posted By: Kestas
Is this the engine with two counterrotating shafts (and pulleys) on the outside?


No, its just the one shaft although in my search for a replacement engine from that era, I have seen a few of the dual shafted PTO ones.

Originally Posted By: 2oldtommy
Following up my previous post, Tha manuel for the Ariens is at http://apache.ariens.com/manuels/prm-10000.pdf This offers part numbers as well as a wealth of info on this old sno blower. FWIW--Oldtommy


The link didnt work for me

 

[2oldtommy]

Try the link without going thru the BITOG server. I pulled it up to make sure it was still working with my Yahoo connection. ---Oldtommy

 

[eljefino]

Jeez, get a short block! Maybe find something that needs a carb or a magneto or some other semi-external part. I'd hate to have you put it back together and find something else worn out of spec. It's pretty easy to find a tecumseh with a malfunctioning, well, anything! They didn't go out of business by being awesome.

IIRC 7 hp is the biggest "small block" and at 8 hp they go up to a "big block" in the tec lineup. Do you want vintage stock or just something that works?

So you like the electric start? Most tecumsehs have them for some reason, even the littler ones. I have a starter I pulled off a junker, it's probably four or five pounds: I use it to hold down a corner of a tarp on my wood pile.

Just seems like a lot of weight to be driving around for an event that happens once.

 

[eljefino]

Originally Posted By: [email protected]
Originally Posted By: HerrStig
How much is a five HP Chonda?


Does the Honda come with electric start? Its one of my dealbreakers. I really dont want to sink $400+ into this 35 year old machine, even with it being in good shape.


You misread. Not honda, CHonda.

Like this one for $99 after coupon.

 

[[email protected]]

Originally Posted By: eljefino
Jeez, get a short block! Maybe find something that needs a carb or a magneto or some other semi-external part. I'd hate to have you put it back together and find something else worn out of spec. It's pretty easy to find a tecumseh with a malfunctioning, well, anything! They didn't go out of business by being awesome.

IIRC 7 hp is the biggest "small block" and at 8 hp they go up to a "big block" in the tec lineup. Do you want vintage stock or just something that works?

So you like the electric start? Most tecumsehs have them for some reason, even the littler ones. I have a starter I pulled off a junker, it's probably four or five pounds: I use it to hold down a corner of a tarp on my wood pile.

Just seems like a lot of weight to be driving around for an event that happens once.


You know, to be honest, I have a Bolens 625 Snowblower that was handed down to me from my Dad but Ive used it since I was a young teenager and its NEVER let me down. Unfortunately, it was mistreated before we got it and its reaching the point of no return. Thats why I searched for another Bolens and ended up finding this one. I "could" take the 6hp Tecumseh off the 625 and put it on the 524, but with the repair so easy on this little 5hp, I figured "why not". It gives me something to do this winter that will (hopefully) keep me outta trouble

Funny you link to that HF Predator engine... I was considering it as a last resort. Somewhere on the web I read you might be able to configure it to accept a Honda electric start kit. But again, its like another $80. I can fix the Tecumseh for less than that and refreshen my small engine rebuild skills in the meantime!

 

[lars11]

I have this one, a Stiga but it is a Bolens. The HS50 tecumseh says "prepared for electric starter" or something and the flywheel has a gear ring so it should be a small problem to fit an 12 v starter on it if yours also has the gear ring. I see them on ebay in the US quite cheap.

 

[[email protected]]

Originally Posted By: lars11
I have this one, a Stiga but it is a Bolens. The HS50 tecumseh says "prepared for electric starter" or something and the flywheel has a gear ring so it should be a small problem to fit an 12 v starter on it if yours also has the gear ring. I see them on ebay in the US quite cheap.

Nice!! Yup, we definitely have twins (or at least cousins) on our hands here, lol.

Mine does have the electric start kit already on it and it works great. I dont know if I mentioned it, but I also have a Bolen 625 snow machine thats on its last legs. I figured it served my family so well over the past 35 years, and thats what lead me to the 524 that I made this thread about.

My engine is a HS50 as well. Wanna trade engines?

 

[Pop_Rivit]

Congratulations for rebuilding it rather than slapping a cheap China built motor on it. Those old original engines are easy to rebuild, and solid as a rock when finished. Leave the "chonda" motors to those without the ability to actually fix something.

Rebuild it and it will outlast several of the chinese motors.

 

[lars11]

haha, no I just got that hs50 engine purring like a kitten after a few hoses, a carb kit and a good cleaning. Seems that it was just neglected, not actually broken. How come these engines runs so much smoother, even at low rpm, than say a Briggs?

I don't have any power or lighting on this one. Anyone knows if that's easy to retrofit or if it's not really prepared for that? Can only find one cable, the kill switch cable.

 

[eljefino]

If there isn't already a light on that blower, you 99% likely don't have the lighting magneto pickup coil. You might need a different flywheel too.

 

[Donald]

Originally Posted By: eljefino
If there isn't already a light on that blower, you 99% likely don't have the lighting magneto pickup coil. You might need a different flywheel too.


My old MW snow blower did not have a headlight so I put a light on my head. OK, looks dorky, but works great.

 

[eljefino]

Originally Posted By: Donald
Originally Posted By: eljefino
If there isn't already a light on that blower, you 99% likely don't have the lighting magneto pickup coil. You might need a different flywheel too.


My old MW snow blower did not have a headlight so I put a light on my head. OK, looks dorky, but works great.


I do that too! IMO it makes me more visible to cars when I clear the end down by the road and it helps me see the controls that I might not see by a handle bar mounted headlight.

Also have some outdoors lights pretty much only used for snowblowing. But when you need 'em you need 'em. Sometimes leave the Xmas lights set up all winter... particularly if they get iced in.

 

[Nick R]

Now that most of the carbeurator issues on our Chonda powered craftsman thrower are resolved (mostly by manually setting a slightly than higher engine speed with the screw, there is no more "idle"(. it works great, runs like a swiss watch.

I ahve no idea how you'd even go about fixing that. Seems to me you'd have to replace the entire crankshaft and that side of the crankcase.

 

[Kestas]

There are esoteric ways of repairing the crank and case, but I agree replacement is the most practical option. Check eBay, people post lots of salvaged parts.