Ironhead cant find this info

[fryday4748]

Whats the compression supposed to be on an 82 sporty?

[runingmouse]

well here is what the FSM manual says.

If the final readings are 120 psi. or more, and final readings do not indicat more than a 10 psi. variance between cylinders. Thats considerd nomal.

this may also help u from stickys - http://xlforum.net/forums/s...ad.php?t=48311

[gungatim]

Compression:

79-81 is 9.0:1
1982 is 8.0:1
83-85 is 8.8:1

Actual PSI in the cylinder will vary but 120-140 is pretty typical.

[fryday4748]

i got 75-80 on each cylinder. but i think i did it wrong. i didnt have the choke ope nor did i have the throttle and slide open all the way. so im gonna re-check it this evening when i get home. im hoping it comes up. she runs good but i am a tinkerer and cant keep my hands off of it lol.

[IronMick]

For a valid static compression test ...

1. Engine must be at full operating temperature
2. Throttle plate must be fully open [throttle grip twisted fully]
3. Choke plate must be fully open [choke knob not pulled out]

If carb has an enrichener rather than a choke then it is irrevelent.

[squirt]

Originally Posted by runingmouse

well here is what the FSM manual says.

If the final readings are 120 psi. or more, and final readings do not indicat more than a 10 psi. variance between cylinders. Thats considerd nomal.

this may also help u from stickys - http://xlforum.net/forums/s...ad.php?t=48311

I find that these numbers are a good starting point for just about any gas engine... Car, truck, motorcycle.

In my opinion, the critical factor here is consistency from cyl to cyl. An older engine that's a bit tired may have slightly lower numbers, but it's not a big deal unless one is reading 90 and the other 120.