The Marine Doctor
Commander
- Joined
- Jul 25, 2003
- Messages
- 2,177
Recently at the shop we had a 1989 Force 85HP.<br /><br />It had been comming back repeatedly for the same problem...it would only hit 4200Rpm's MAX. Spark was fine DVA tested all the components...compression was fine all around 150psi.<br />Reeds were fine ect. <br />For arguements sake the engine should have ran at 5500Rpm's with the test wheel.<br /><br />Finally after much debate I sprayed air into the intake baffle while the engine was running at Full Throttle.<br /><br />NOTE I did not spray directly into the carbs. Just increased the availability of the air to the carbs.<br /><br />Anyhow...the Rpm's increased by 200<br /><br />Right then I knew what was happening, Too much fuel at highspeed. Elevation here is 2000-5000 which requires the Main Jet to be .072, the engine from factory came with .076. I popped out the old jets and put in the new ones. Low and behold..5500Rpm's and sounded great.<br /><br />Here were the symptoms. Huge amount of smoke at highspeed...Max Rpm's 4200...<---did not matter what pitch the prop was. Ran at 4200 with a 15 or a 19. Smelled of fuel after running at highspeed.<br /><br />I guess what I am trying to say here, is if you have a Force/Chrysler and have exhausted all leads of why it will not perform as good as it should...even though it should be. Look at the jetting it might be getting way too much fuel.<br /><br />Always check your elevation vs Jet size before changing.<br /><br />I think this Tip might help out a lot of discouraged Force/Chrysler users.<br /><br />TMD