Help with Compression Gauge

[350Kris]

I'm going to get a compression gauge to check my 85 250R. It's been running so good for a few years that it worries me! I saw that Harbor Freight has some ranging from 10-15 bucks. I usually like to buy the best tools, but I don't like to overbuy. Are the US General ones they sell good to go? Any help would be appreciated.

http://search.harborfreight.com/cpisearch/web/search.do?keyword=compression+gauge

[RedRider_AK]

I used a Harbor Freight compression gauge and it never gave me an accurate reading twice in a row. It would say 125 one time and then 115 the next, and 130 the next. Get one of the screw-on kinds with a rubber o-ring around the sealing area and an air-tool style chuck on it. I have one (forgot brand) and it always tests the same.