Have a pontoon with a 05 Mecury 90 hp 4 stroke engine and it has lack of power and hesitation at mid range rpms. It starts great and seems to run fine at higher rpms (above 3000). If you run it between 1800 and 2500 rpm it seems to loose power and has a vibration. Had somebody come over and look at it and tested the fuel delivery and said it tested fine, also tested ignition and said it is getting spark. Then tested compression and 2 cylinders tested at 170 psi and the other was at 130-135 psi. He said it needs to be rebuilt. I am a little bit shocked as this engine has about 100 hours on it and it seems a bit early for it to need a rebuild. Is this a common isuse with this engine? Are those compression numbers normal? Are there other issues that could cause the hesitation that should be checked out first before we jump into a engine rebuild? Any help woudl be greatly appreciated.
Thanks!
Thanks!