Mecruiser 5.7 Acceleration Issue
 

I have a 99 SeaRay 215 EC with a Mecrusier 5.7 engine. It starts and idles fine but when I accelerate it bogs and slowly accelerates at first and once the RPMs hit 2800-3000 it quickly picks up and gets on a plane and acts normally until you pull back to idle and try to accelerate again which starts the pattern all over. I have cleaned the carb, used a fuel treatment, changed out the fuel/water filter, and tested the fuel pump. Looking for anyone else who has had a similar issue and how to fix or at least troubleshoot better. Thanks!

When you cleaned the carb did you disassemble it, soak it, and reassemble with a kit?
If so was the accelarator pump bad and a new one installed?
Did you check the fuel tank antisiphon valve sticking?
You should pull the plugs and check for evidence of water intrusion!
Have you run a compression check to see if all cylinders are functioning?
Is the motor fireing on all 8 Cyl.?
All of these can contribute to those symptoms, a small 8 will idle fine on 7 cyl. be hard to plane, and then run again once over the hill to a point. Go back to basics ck spark, compression, wires, choke, etc.
Bosco

Thanks Bosco I will check out the items you suggested. To clarify when the RPMs hit around 3K I am still bow up when it starts to accelerate and I have not had an issue getting up to top speed once there and the engine sounds normal, I would expect you would be able to tell if a cylinder was missing at high speed but I could be wrong.. The carb cleaning was chemical and not a disassemble and rebuild kit.