KitLog pro

Powered By Kitlog Pro v2.0

Steve's CH750 Cruzer (N750SB)
' style=
Date:  2-21-2019
Number of Hours:  2.75
Manual Reference:  
Brief Description:  Compression Test

Granted I'm new at engine compression testing, but even I can tell the Harbor Freight Leak-Down tester is crap after trying to use it. The gauges are sticky and non-responsive. The 12mm attachment that screws into the spark plug hole is too large to fit down the tube. I ended up grinding down the corners to get it to fit. It will be returned this week. Ok, enough venting.

The access tubes to the spark plugs are deep and narrow. I had to locate a 14mm THIN WALL spark plug socket, which I found at AutoZone.

A single bolt holds the coil tubes in place. They were easily removed, providing access to the plugs. With the proper socket, the plugs came loose easily enough, but getting them out of the tube required engaging the clip end of the coil tube to lift it out.

Once all the plugs were out, locating Top Dead Center of each cylinder became the task. I attached the tester tube to the plug hole and by putting my finger over the other end was able to determine where in the cycle TDC was approximately. Inserting a stiff wire through the plug hole and determining where it bottomed topped out gave an exact position.

As near as I could tell, all cylinders read about 15% leakage, which at 80lbs test pressure would be 68lbs compression. Not sure about the accuracy of that, but since all the cylinders are not likely to be bad, as long as they appear similar to each other, I'm going to call it good for a low time auto engine until I get better test gear.

Reassembly and test run went without incident.
' style=

Copyright © 2001-2022 Matronics. All Rights Reserved.