OCTANE RATING CHART
| Compression | Octane rating |
| Up to 180 psi. | 93 s.u. pump gas |
| 180 – 200 psi | 100 |
| 200 – 210 psi. | 105 |
| 210 psi. & up | 112 or higher |
Degree
|
550 | 650 | 750 | |
| 17 | .065 | .079 | .079 | |
| 18 | .075 | .089 | .088 | |
| 19 | .085 | .099 | .099 | |
| 20 | .095 | .109 | .110 | |
| 21 | .105 | .119 | .123 | |
| 22 | .115 | .130 | .134 | |
| 23 | .125 | .148 | .144 | |
| 24 | .135 | .159 | .158 | |
| 25 | .145 | .169 | .169 | |
| 26 | .155 | .175 | .181 | |
| 27 | .165 | .195 | .197 | |
| 28 | .175 | .210 | .213 |
| Stock Timing | Recommended Timing |
| 440 P.P. all 28 deg | 26 – 28 |
| 550 P.P. 82-85 28 deg | 26 – 28 |
| 550 P.P. 86-90 21 deg | 26 – 28 |
| 550 reed Kawasaki 21 deg | 26 – 28 |
| 650 all 21 deg | 21 – 25 |
| 750 Total Loss | 21 – 24 |
At Dale’s your pride and joy never has to leave our shop for any machine work. We maintain a full service on-site machine shop and test tank facilities for repairs, engine rebuilds and high performance modifications.
If you are looking for OEM factory replacement, aftermarket parts, watercraft accessories or just need some help diagnosing a problem contact us. That's what we are here for. 
Training - Safty - Organizers - More many be found at PWC Associations Page under contacts