Compression Testing Issues

outatime andy /

Anybody here have success or experience with the Harbor Freight compression test kit?

Just got one last week and was getting readings of about 50 PSI.

The bike runs great and acceleration is good. Just wanted to test my compression for tuning. I've heard the hose/no hose debate for small engines, which didn't help at all. I would just like to hear about personal experiences or other recommendations. Thanks

compression.jpg

Re: Compression Testing Issues

Just open yer throttle and turn it over. With a long hose, crank it more.

Re: Compression Testing Issues

Loaner tool programs @

Oriellys, Autozone,advance auto and who ever else. Drive yer moped to all of them and try out thier guages for comparison.

Motor should be warm with throttle all the way open while testing each. (edited)

Re: Compression Testing Issues

If that's the one that comes in the red box with all kinds of different hoses it's JUNK! In work once of twice right then it's all over the place. Yes I had not one but two of them and the same thing. Go to any parts store and buy the cheapest one from behind the counter and you'll be WAY better off.

Re: Compression Testing Issues

That's a cheap one alright.

Re: Compression Testing Issues

Just used the loaner program this morning..Got a bearing splitter...took a half hour .. took it back , my refund. Worked out good. The freezer method didn't work out..

Re: Compression Testing Issues

Joe Schuitema /

I've used the mityvac compression tester on a half dozen small bikes and works well and repeatable. Ends are crimped well and don't slip.

https://www.amazon.com/dp/B0002WSC0G/

Re: Compression Testing Issues

> Les B. Wrote:

> -------------------------------------------------------

> Just used the loaner program this morning..Got a bearing splitter...took

> a half hour .. took it back , my refund. Worked out good. The freezer

> method didn't work out.

Installing the bearing with the freezer works fine for me. I don’t even need to freeze the crank , I just put the the bearing in the over set it to 220 and check on them with a temp gun.

Re: Compression Testing Issues

Oh! I screwed up... I froze it to take off...

Re: Compression Testing Issues

I have a cheap compression tester too (not HF)...the schrader valve quit after about 5 uses...bought the correct valve for another tester and installed...I also use the hose and get pretty regular 100-125psi on my bikes...

the valve is at the end of the hose that attaches to the spark plug hole so i don't think it impacts the readings

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