Found another use for the LM-1....
12-29-2006, 06:14 PM
#1
Instructor
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Found another use for the LM-1....
This may be old stuff to some, but today I used my LM-1 to check for those pesky vacuum leaks. I disconnected all my vacuum accessories except the vacuum advance can and took a reading at idle from the LM-1. I connected the hoses back and was shocked to see how much the numbers changed. I found a leaky headlight valve and a leaky connection at the heater control panel. With a pair of clamps it's easy to clamp off the hoses, read the LM-1 and see where the problem is! Fortunately these leaks didn't seem to screw up my carb tuning.
12-29-2006, 06:55 PM
#2
Race Director
Interesting. If you had it set up correctly with the vacuum connected, I am guessing that the car ran rich with the vac pinched off. Just trying to figure out how you learned. 
12-30-2006, 09:19 AM
#3
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Exactly right. With everything disconnected I adjusted the idle mixture to an AFR of 14. With everything hooked up my AFR went to 17. As I pinched off the leaking hoses/devices you can see an immediate change in the meter back down to the 14 setting.
I don't think I have any leaks but this is an easy check.
01-01-2007, 08:52 AM
#9
Le Mans Master
