So I just bought a Proform (pro-66834) suppose to be good up to 700lbs.

The springs i use in my engines is PSI DR1249. Suppose to be 385# @2.200 and 1110# @ 1.200.

So i put it in the vice and compressed the spring to 2.200 and i get a reading of 250# on the tester.

Tried another spring same thing.

Pulled out a NEW box of DR1249. Same thing.....

Pulled out a OLD box of used springs from a season or two ago and same thing....

Am I doing something wrong or????

Thank you

I have one of those testers,and it reads right on what the springs I have been checking with it should.I have checked springs from 149 seat to 475 open on it and they check good.
Are you sure you are looking at the little rule on the side correctly?
Keith

put a retainer on one end of the spring.

Are they suppose to be tested with a retainer>?

Yes

some retainers preload the inner spring which will give you a higher reading.

2.200 is the installed height of the outer spring. Have to use the retainer or some washers to simulate the step for the inner spring.

Dont use a retainer, but as mentioned, a washer spacer. Most steps of the retainers are from .080-.120, with the most common racing types being .100ish. If you use a retainer you will be adding more that the actual installed height. You want to use a spacer just for the inner spring. You will see a quite different reading I suspect.

I had a old retainter and I went through all 16 springs and they all came out around 360 +/-5.

When a spring is bad what would the reading be? 300? 340? 100?

The card from PSI said the springs were suppose to be 385 at 2.200. With my tester it seems like they are at 385 at 2.185-2.190

I am wondering if your tester is filled all the way
with oil(air compresses)

Do you know anybody with a traditional spring checker that you could use to compare?

That is the logical thing to do. I bet you'll see a difference.A calibration spring would tell a lot also.

due to the variation you'd get with different spring compressers, i use the same tool every time. the type you use on the head to compress seems to be a bit hit n miss to get an accurate reading so i use the shotgun cartridge reloader style tester. i tested my current springs brand new with the retainer i'm using on the motor so i had a reference point & found my spring reading as 15 psi short of advertised reading. each year i pull all my springs & retest. after my first season they'd dropped by 20psi, but each year since they haven't dropped any further. if your spring has dropped off by 15% of manufacturers spec or more i'd be looking to replace them.

There's an old saying...."A man with a watch knows what time it is, a man with two watches is never sure".

Same goes for just about every measuring device, I've got a half-dozen tire pressure gauges and............

My proform #66834 would always read light also. Thanks to all who contributed on this thread, I now know why. In my case it was "stupid me".