# Engine rebuild



## shark56 (Nov 26, 2014)

Hello, I have a 1997 Tecumseh hmsk100 10hp snowblower. I am in the process of rebuilding the engine. I have put in the new connecting rod and piston and have bolted it to the crankshaft. I just put the camshaft in and have lined up the timing marks correctly. When I go to turn the engine over to make sure everything is ok, the gears get very very hard to turn when the intake valve goes up. Is this normal for this to happen? I just want to make sure that everythings ok before I go through all the trouble of putting it back together, only to find out that I have to tear it down again. what do you guys think?

thanks!


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## micah68kj (Oct 8, 2011)

Never rebuilt one of those but it doesn't seem right. I'd double check all the components and make double sure everything is correct. Possible bent valve stem? Valve too long? :smiley-confused013:


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## Kiss4aFrog (Nov 3, 2013)

If the plug is out so you're not fighting compression it should have almost the same feel all the time. IMHO the valves don't give much resistance at all unless there is something binding like Micah pointed out.

How does it feel when it's on the exhaust stroke and opening up the exhaust valve ??


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## shark56 (Nov 26, 2014)

I do not have the sump cover on or the cylinder head yet, so I don't know if that might be part of the problem. I am simply just spinning the crankshaft. when I spin the shaft, the exhast valve gives little resistance and spins smoothly. when the intake valve begins to open, that's when I'm experiencing a lot of the resistance. Is this normal maybe because that is the power stroke?


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## YSHSfan (Jun 25, 2014)

shark56 said:


> I do not have the sump cover on or the cylinder head yet, so I don't know if that might be part of the problem. I am simply just spinning the crankshaft. when I spin the shaft, the exhast valve gives little resistance and spins smoothly. when the intake valve begins to open, that's when I'm experiencing a lot of the resistance. Is this normal maybe because that is the power stroke?


If the cylinder head is not installed (it is not building compression), the crank should turn smoothly with very little resistance when lifting the valves.
Something is not right with the intake valve, you should inspect it closely. Did it get dropped? Is it bent?


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## shark56 (Nov 26, 2014)

I never removed the valves because I was not doing a complete engine rebuild. I only put in new piston rings and a new connecting rod. I cant think of any way how the valves could have been damaged, because they weren't removed.


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## 94EG8 (Feb 13, 2014)

If the sump cover isn't on yet it will cause binding. You can put it on without the gasket and just stick a couple of bolts in it to try.


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## scrappy (Dec 7, 2014)

94EG8 said:


> If the sump cover isn't on yet it will cause binding. You can put it on without the gasket and just stick a couple of bolts in it to try.


plus 1


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## YSHSfan (Jun 25, 2014)

94EG8 said:


> If the sump cover isn't on yet it will cause binding. You can put it on without the gasket and just stick a couple of bolts in it to try.


+1 
I missed that part :facepalm_zpsdj194qh


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## skutflut (Oct 16, 2015)

shark56 said:


> I never removed the valves because I was not doing a complete engine rebuild. I only put in new piston rings and a new connecting rod. I cant think of any way how the valves could have been damaged, because they weren't removed.


Just curious as to what prompted the rebuild. Since you are into the engine anyway, why not remove the valves and check them for wear, condition of valve seats, springs, etc. If you didn't remove the valves, you cannot be sure that the intake valve is not bent. Is there any signs of wear on the cam shaft lobes, either exhaust or intake? How about the lifters?


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## shark56 (Nov 26, 2014)

I didn't remove the valves because I was only replacing the piston rings. I will check my valve clearance tomorrow and see if its ok. I never had a problem with the valves before I took it apart. I will also try putting the sump cover on and seeing if that will help.


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