454 mag with b&m blower, tech qiestions???
#21
Good idea! Another one, is your gas fresh and 93 octane? I would also verify thet your ignition timing is 30-32 degrees above 3000 rpm's.
Last edited by PatriYacht; 07-22-2009 at 02:28 PM.
#22
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From: Lake Milton , ohio
im pulling th carb tonite, taking it to get cleaned and checked,, when i get it back im gonna get some one to help me check the timming,,
im just frusterated cause this motor/carb/blower/wires/ignition/pumps/belts/ everything, is all the same from the previous owner, and he was getting 5400rpms..? the only difference is fuel pumps and exhaust...? so maby carb gummed up from sitting, but is was supposed to be less than a yr the motor was sitting...
#23
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From: Lake Milton , ohio
#26
To little timing is as bad as too much. Too little will kill the exhaust valves with heat. Do a search, the vast majority here run 28-32. I think this is a pretty mild set up and a couple more degrees will help around the dock.
#27
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From: Lake Milton , ohio
i lined up a set of headers, i believe their Lightning, should have them next week... i dropped my carb off at a performance carb shop in town, and with just the bowls off, and looking down the plentum, he said it looked bad..??? but i dont know why, the previous owner said it it was running fine last summer?? but i get the carb back today, and will run it this weekend witht he stock exhaust and see what kinds of gains i get, then well check the timming... and next week add headers... trying to 100% eliminate all possible problems.... im runnin out of summer in ohio!!!
#28
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From: Lake Milton , ohio
also, the boat has 4' GIL tips, but they have a spiril baffel in them,,, the boat is super quiet, is this hurrting perfromance? or just for noise??? should i change these, esp when im running headers??
thanks again everyone...
thanks again everyone...
#29
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From: Lake Milton , ohio
Once you get the carb cleaned/setup, and headers you may want to try a 25 pitch mirage + (three blade) prop. You said this engine came out of a twin setup. The 4 blade bravo may be a little to much prop. Plus older bajas run the drive very deep in the water and do not work well with 4 blade props.
The swirl tips do not cause much if any loss of power on engines under 500 cu in. I have a 280 sport with twin 400 hp and I changed out the swirl tips and it made no difference in performance, just better sound.
Good luck with your new boat.
The swirl tips do not cause much if any loss of power on engines under 500 cu in. I have a 280 sport with twin 400 hp and I changed out the swirl tips and it made no difference in performance, just better sound.
Good luck with your new boat.




