Compression test readings

[Dirtdigger04]

Hey, i gave 3 of my dirt bikes compression tests today with a compression gauge and my results were the following:
1. 1975 Honda Elsinore CR250- 107-112 psi
2. 1976 Honda Elsinore MR250- 105 psi-110 psi
3. 2000 Suzuki DS80- 75- 80 psi
Are these results normal?

 

[RM_guy]

They all sound low and probably need new pistons as well as rings. On iron bore jugs you will most likely need a bore job too.

 

[jb_dallas]

Was the engine at operating temp when you did the compression tests? Was the throttle wide open? Did you test compression several times on each bike to make sure you are getting an accurate reading? A compression test is sort of a half azz way to test the wear of an engine. Compression tester readings may vary widely. One compression tester may read 105 lbs and the next one 130 or 140 on the same bike.

 

[Dirtdigger04]

No, i did all the compression tests when the engine was cold. I made sure i held the throttle wide open. I did the compression test maybe 15 times for each bike, and the above results were the average for each bike.

 

[whenfoxforks-ruled]

They are averagely worn out then. Compression gauge: After the engine is broke in, check and record the measurement. Check it frequently, when a small drop is noticed, rering it. Other than that, you might as well play horse shoes with that gauge. Vintage Bob

 

[StreetLimitz89]

i freshly rebuilt the top end on my 91 cr 125 and before we started it up we decided to test the compression on the cold engine and it had 208psi compression, after the break in and all the good stuff it was doing a easy 2-3 kick 150-160 psi