3.5HP Tecumseh on a Chipper/Shredder

itsgalf

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Aug 11, 2018
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Hello all, I'm trying to fix up a Chipper/Shredder where the compression is very low (35 psi). Tecumseh H35-45696S
I lapped the valves and shaved off a little from the exhaust valve to get the proper valve clearance. Still low compression.
I put some engine oil down the spark plug hole to perform a wet compression test (probably should have done this first - still learning) and compression rose to about 80 psi.
Looks like a piston ring job. Never done one before - hopefully I can tackle it.

Now the problem is getting the shredder impeller off of the shaft so I can dismount the engine to work on it. Looks like I need a large puller. Any one with good tips?
Model: MTD 242-640-000

IMG_20190919_120629611.jpg
 

dougand3

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Guessing here...any secure place to hook an 8-12" puller? Parts stores have them as loaner tools.
Ring sets...the few times I looked up buying them for 4-6 hp mower engines, they were ~$40. Phhhfffsttt. I found mowers with carb problems for $20 and mounted them.
 

bertsmobile1

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That is a no nonsense looking piece of kit.
To remove the rotor use the same method as removing a stuck wheel
Start with multiple heating cycles, heat it very hot then cool with water spray
Towards the end, let it cool a bit slower then when about 200 deg ( just too hot to touch spray your favourite penetrant around the shaft.
Repeat this a few times

Now apply some pressure to the rotor , pry bars, wedges etc and with this applied hit the crank shaft .
An air hammer works best
As it moves make sure you keep up the pulling pressure on the rotor.
A two person job if you are using pry bars.

When you get it off, some never seize is a good idea & try to remember to pull it off every few years.
 

Fish

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Have you tried to start the engine?


Compression readings on small engines are not very accurate..
 

itsgalf

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Aug 11, 2018
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Thanks for the responses. Should be fun

I have tried to start it. Good spark and clean carburetor. Even used some carb cleaner in the spark plug hole before pulling it over. Still couldn't get it going.
I realize there's a compression release mechanism, but doing the wet compression test led to a noticeably higher compression reading - so should be the rings I think
 
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