Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

20 year old Tecumseh 5hp rehabilitation


ben0712's Avatar
Member

Join Date: Nov 2010
Posts: 3
NY

11-18-10, 06:26 AM   #1  
20 year old Tecumseh 5hp rehabilitation

Hello,

This is my first post regarding a 5hp Tecumseh engine, Model # H50-65499P. I found an old Garden Way chipper/shredder for sale for $150 at a garage sale a few weeks ago. The owner said he'd inherited it from a neighbor for whom he did some light handyman work, that it was from "about '85 or '90" and that it had been used about 4 hours over its lifetime. The engine started right up and we were able to send a stick through and shred it, so I bought it.

I ran it for about a half hour on both the chipper and shredder openings and things worked fine. The engine required half choke to run, so I knew I probably needed to clean the carb out good. The belt was dry rotted. I replaced the spark plug and air filter, and I replaced the belt. I changed the oil (probably for the first time in its life) and the oil was dirty but no metal shavings evident.

Now here's the problem. What I didn't realize was that the replacement belt I got was 29", and the spec was 29 1/4". With this size belt the clutch couldn't completely disengage. Proper operation requires the engine to get up to full throttle, then engage the clutch to turn the shredder assembly. Well, I didn't do that. I disengaged the clutch as far as I could, started it, and engaged the clutch before it got up to full speed. I was able to get it started, but it ran for about two minutes (turning the shredder) before the engine quit. At that point the pull-starter wouldn't budge.

I removed the starter to get access to the flywheel nut. Turning the flywheel manually with the clutch disengaged, I could feel some resistance, so I inspected the belt and realized it was a quarter inch too short. I removed the belt and rotated the flywheel, and I can still feel some resistance at one specific point in the rotation. It feels like something is grinding inside the engine. I pulled the dipstick and discovered metal shavings in the oil.

Now, my question is, where do I go from here? Have I wrecked this engine? What did I do exactly and what can I do to rehabilitate this fine old machine? I am not super-experienced with small engines but I'm a quick study, and I am willing to do a complete tear-down to learn more. Thanks!

 
Sponsored Links
marbobj's Avatar
Member

Join Date: May 2006
Posts: 3,659
IA

11-18-10, 08:53 AM   #2  
There's a fair chance the engine is done, but I would pull the head (easy to do) and see if the cylinder is scored. If not the connecting rod is likely where the shavings came from = likely a crank resurfacing, but definitely a rod.

I would say look for a replacement engine, but if the damage is something you want to mess with as a project see where the damage is first, then decide.

If the oil was pretty crudded up the passage to the journal was probably plugged and couldn't allow oil to the crank/rod bearing.

 
ben0712's Avatar
Member

Join Date: Nov 2010
Posts: 3
NY

11-22-10, 05:21 PM   #3  
Thank you. Like I said, I'm kinda new to small engine repair. You say it's easy to do, what's the basic steps to pull the head? I googled around for "pull cylinder head" and variations but didn't come up with much useful. Is there a good book I should buy to walk me through this or any decent websites that show me how? Thanks!

 
geogrubb's Avatar
Member

Join Date: Jun 2006
Posts: 2,333
MO

11-22-10, 05:29 PM   #4  
The link below covers your engine. Have a good one. Geo
http://www.cpdonline.com/692509.pdf.

 
ben0712's Avatar
Member

Join Date: Nov 2010
Posts: 3
NY

11-29-10, 11:10 AM   #5  
Thanks a ton for that link!

I removed the screws from the top of the engine to get at the valves and cylinder to inspect it. Here's a couple of pictures of the bolts once I removed them. There was a packed pyramidal cone of metal shavings on the end of the bolts. Not sure what that means.




When I removed the valve cover I found a fair amount of carbon. (see pics) I'm scrubbing that off with a sponge and some WD-40. As I rotate the flywheel, the cylinder moves freely until it is exactly halfway through the stroke. When it's moving down, I can see it rubs a bit on the bore and leaves a streak in the oil.

Marbobj, the cylinder has a lot of carbon on it, but it does not appear to be scored. I also inspected the bore and that does not appear to be damaged, either.

What's next?




Edit: Inline links not working, here's the links to the pictures:
https://docs.google.com/leaf?id=0B97...Y2VmNzUz&hl=en
https://docs.google.com/leaf?id=0B97...YTdlNmQ1&hl=en
https://docs.google.com/leaf?id=0B97...Yzc4YTFj&hl=en
https://docs.google.com/leaf?id=0B97...NTllYTc3&hl=en


Last edited by ben0712; 11-29-10 at 11:14 AM. Reason: Fix Image links
 
marbobj's Avatar
Member

Join Date: May 2006
Posts: 3,659
IA

11-30-10, 08:03 PM   #6  
The filings on the end of the bolt probably came from the threads of the bolt holes in the block.

I suspect the filings in the oil did come from the the crank/rod. You'll have to pull the sump off to get to the crank so you can take off the rod cap and see what you have.

 
Search this Thread