dyno check list
1) FULL TANK OF FUEL (FUEL YOU WILL BE RUNNING) (NO OCTAIN BOOSTERS)
2) GOOD BACK TIRE
3) 40 PSI TIRE PRESSURE
4) CHECK OIL ( MOTOR, PRIMARY & TRANS )
5) BELT TENSION
6) CLEAN AIR FILTER
7) NO LEAKS
8) NO CHECK ENGINE LIGHTS ON
The numbers shouldn't deviate more than 10% from front to rear cylinders. Some aggressive cams will drop your readings by 20 to 30%, so do not get too concerned if the #s are lower. Also, make sure the compression releases are turned off, and they do not have easy start cams, or the #s will be even lower.
8:1-8.5:1 compression: 150-170 psi per cylinder
8.5:1~9.5:1 compression: 170-210 psi per cylinder
9.5:1~11:1 compression: 210-275 psi per cylinder
11:1+ compression: 250+ per cylinder (highly depends on cams being used)
The tested numbers should not vary anymore than 10% from cylinder to cylinder or this may indicate a problem.
Results: Cylinder #1 ______ Cylinder #2 ______ Percent difference _______
Run the correct heat range plug and gap for your application. A boosted bike will need a much tighter gap than an all-motor setup. If you do not know what plugs to run or what to gap them at, give us a call.
An oil and filter change is a good idea prior to tuning if it has been more than 3,000 miles since the last oil change, or if the engine has been repeatedly flooded from a poor tune or any other reason.