Bigdave196
Petty Officer 2nd Class
- Joined
- Apr 13, 2009
- Messages
- 120
Ok, Im a NEWB here and I am calling out for some help before I have to shell out more greenbacks to get this minor problem fixed.
I have a 1995 Bluewater Open bow ski boat with a 5.7 going to an Alpha1 outdrive with a Steel Quicksilver 19-pitch 3 blade prop. Last year we had the brilliant idea to run out 2 year old gas instead of pumping it out and leaned out the #4 cyl. Well $2000 later we had the motor rebuild by a very reputible shop and bumped it from 220hp to 300hp. I am running a factory distributer with Accell 8mm wires and a MSD Blaster coil for 50K volts of spark to AC Delco Iriduim plugs. Factory Elelbroc Carb (4bbl) unknown size for CFM. With the last motor I could easily turn 4900-5500 RPMS and get around 60MPH with this setup. Timing was factory.
New motor now has almost 80HP increase, and Timing is at 15 degrees BTC. I have awesome hole power now (compared to when the #4 Cyl was shot) and the engine runs so smooth, but now it wont pull over 4000rpm. I am maybe getting 35MPH out of the boat so far. I have played with the air/fuel screws to get it to this RPM, but I cant get any further. I do not want to lean it out again and I am at a loss for what to do. The builder of the motor said that to hear this boat "sing" I need a Demon 800 Marine carb. Thats $800 that I really dont want to spend unless I have to. So my questions are,
1. Do I have a CFM issue with the old Carb because I went up 80 HP?
2. Do I just need to re-jet my carb?
3. Is my Edelbroc carb just insufficient to handle 300HP?
Any other ideas on where to look or what to look for??
This boat has given us almost 1000 hours of enjoyment and we keep in in really good shape, and now I am frusterated.
Thank You in advance.
Dave
I have a 1995 Bluewater Open bow ski boat with a 5.7 going to an Alpha1 outdrive with a Steel Quicksilver 19-pitch 3 blade prop. Last year we had the brilliant idea to run out 2 year old gas instead of pumping it out and leaned out the #4 cyl. Well $2000 later we had the motor rebuild by a very reputible shop and bumped it from 220hp to 300hp. I am running a factory distributer with Accell 8mm wires and a MSD Blaster coil for 50K volts of spark to AC Delco Iriduim plugs. Factory Elelbroc Carb (4bbl) unknown size for CFM. With the last motor I could easily turn 4900-5500 RPMS and get around 60MPH with this setup. Timing was factory.
New motor now has almost 80HP increase, and Timing is at 15 degrees BTC. I have awesome hole power now (compared to when the #4 Cyl was shot) and the engine runs so smooth, but now it wont pull over 4000rpm. I am maybe getting 35MPH out of the boat so far. I have played with the air/fuel screws to get it to this RPM, but I cant get any further. I do not want to lean it out again and I am at a loss for what to do. The builder of the motor said that to hear this boat "sing" I need a Demon 800 Marine carb. Thats $800 that I really dont want to spend unless I have to. So my questions are,
1. Do I have a CFM issue with the old Carb because I went up 80 HP?
2. Do I just need to re-jet my carb?
3. Is my Edelbroc carb just insufficient to handle 300HP?
Any other ideas on where to look or what to look for??
This boat has given us almost 1000 hours of enjoyment and we keep in in really good shape, and now I am frusterated.
Thank You in advance.
Dave
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