Wednesday, August 11, 2010

Carburetors are Less Scary

This is actually one of the scariest things I have done to my VW.  With help from my friend Dave (made famous in an earlier post), I completely disassembled the carb.  I replaced gaskets and seals, and gave everything a thorough cleaning followed by some quality time with an air gun.

Learning experience: when the instructions say "Pay attention to how this spring was installed" what they really mean is "put it back the same way."  I didn't, and as a result my accelerator pump wasn't working, and the Thing really wouldn't run at all.  Dave deduced that the accelerator pump wasn't working so something must be wrong in that area, and he found I had put the spring in backwards.

Dave was also kind enough to check and adjust my valve clearances. They should all be 0.006, and some were a little off. In particular, #3 had very little clearance at all. This is a problem because it means the valve doesn't sit closed long enough to allow its retained heat to conduct through the head. This can lead to valve failure and horrible engine damage. I'm noting the valve clearances before adjustment here; if we find that #3 is consistently getting too tight more drastic action will have to be taken.

Cylinder Valve Clearance (inches)
1 exhaust .005
intake .003
2 intake .006
exhaust .004
3 exhaust less than .002
intake less than .002
4 intake .004
exhaust .003