Rebuilding Craftsmen 19.5 Twin Clinder Tractor Engine - Help!

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  #1  
Old 02-24-07, 04:35 PM
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Rebuilding Craftsmen 19.5 Twin Clinder Tractor Engine - Help!

I have posted before concerning the tractor and have received excellent advice, so here is another issue.....

I have replaced a bent valve as well as a snapped connecting rod. From what I can determine the engine is not in the bad of shape internally. My problem is two fold..

1. Upon connecting the new connecting rod (with piston attached) to the crankshaft as I try to torque it down it seems to bind the crank shaft and I cannot rotate the crankshaft. It gets stuck. If the connecting rod bolts are loosened the crank shaft rotates fine. Is there a trick to assembly or do I have bigger issues.

2. I replaced the exhaust valve and upon the return stroke the valve does not seem to seat perfectly. If I shine a light in the bleed compartment I can seem a small amount of light coming out. Will I get compression upon the intake stroke?

Thank you,

Doug
 
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Old 02-24-07, 07:49 PM
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Location: Marion,Al.
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Usually when a connecting rod beakes its because of Excessive heat and low to no oil and it goulds the crank journal.If this happened you have to take the crank totally out and polish it up in order for it to be smooth and round .again. If it still fits too tight to move you'll have to take the crank and rod to a mechine shop to let them turn the crank down to mach the rod.And if it's bad enough you'll have to buy a 0.010 or 0.020 under stzed rod,in order to get things to fit right again.


As far as the valve goes if you can see any light through the head when the valve is supposed to be closed,that valve is going to leak and you wont get the max. amount of compresson to crank your engine.Clean the head and re-lap that valve until there is a dark gray ring all the way around it (not broken anywhere).
 
  #3  
Old 02-25-07, 04:29 PM
Join Date: Jan 2007
Location: London
Posts: 105
Personally, in such situations, I pick up an undersize rod and take it and the crank straight to an automotive machine shop for turning and matching. They can usually do it within a day or two and you will know it was done right. They have the equipment and the skill and these little cranks are no big deal as far as they are concerned.

I have also had them shave warped heads with complete success and a lot better and faster than I could do it even on a good day.
 
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