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Discussion Starter · #1 ·
My '67 JD60 appears to have some exhaust blow-by somewhere near the muffler, but I just can't pinpoint it. Does anyone have any experience with any cracks or issues at or near the muffler? Also, I assume there is no replacement part for the muffler. My best bet is to probably clean the one up I have, right?
 

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George, leaks at the muffler or pipe are not very common unless the rear of the muffler has rusted out. More common is a partially blown head gasket resulting is an accumulation of a black oily substance on the fins and block in the area of the muffler. It's a simple fix to remove the head, de-carbonize it, lap it flat, and replace it with a new gasket. Following the procedure in the Service Manual for torquing the head bolts is important.
 

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Discussion Starter · #7 ·
Hey Stan- thanks for the info, and sorry it has taken so long to get back to you. I think you may be right about the partially blown head gasket. I am still using the tractor, but would like to fix it. Is the new gasket readily available? Also, I have a rookie question- What do you mean by lap it flat? Don't know if I have the proper equipment for that.

Also- how would the partially blown gasket effect the engines power output?
 

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A blown head gasket causes reduced compression and lower power output. Continued running with a leaking gasket can result in burning/erosion of the block or head.

The head gasket and engine gasket set are NLA from Deere but may be available from a Tecumseh or small engine parts dealer.

"Lapping" is the process of making the surfaces of a warped head perfectly flat to avoid gasket blow-out. One way is to tape a piece of 80 or 100 grit aluminum oxide sandpaper to a flat surface like the table of a table saw, and with a little oil on the sandpaper move the head in an orbital motion holding firm, steady pressure on it. After a minute or two wipe off the head surface and look at the coloration. Dark or shiny spots indicate the need for more lapping; an even dull gray color is what you want to see. Using this method I've never spent more than 15 minutes lapping a head from any L&G tractor.
 

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Discussion Starter · #9 ·
I finally got a chance to replace the head gasket, and lapped the head flat after cleaning everything else up. Is it common to have to adjust the carb after completing this? I seem to be running a little rich/rough. I am going to play around with it this week to see if my problem is solved.
 
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