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BF15A ENGINE WILL NOT REACH MAX RPM

J

JIMMY LEE

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"I HAVE A 94 15 HP HONDA THE E

"I HAVE A 94 15 HP HONDA THE ENGINE HAS RAN GREAT FOR YEARS. RECENTLY (PAST 2YRS) IT HAS DEVELOPED LACK OF POWER AT WOT. IT WILL NOT PLANE MY 14 FT V-HULL WITH TWO PEOPLE AND A LITTLE FISHING GEAR. I HAVE TRIED EVERYTHING. THE COMPRESSION IS WITHIN SERVICE MANUAL SPECIFICATIONS. I HAVE CHECKED FOR TIMING BELT SLIPPAGE. I HAVE DISASSEMBLED THE ENGINE AND CHECKED FOR CLOGGED EXHAUST PORTS. I HAVE TOTALLY CLEANED AND REBUILT THE CARBURATOR. I HAVE TRIED A FRIEND'S CDI BOX. I HAVE TRIED TWO DIFFERENT PROPS. I NOW HAVE A 9.25 X 8 X 3 FACTORY PROP. I HAVE ADJUSTED THE VALVES TWICE. I HAVE CHECKED CAM SHAFT AND CRANK SHAFT KEYWAYS FOR SHIRRING. I HAVE REPLACED FUEL TANK AND LINES, REPLACED FUEL FILTER AND SPARK PLUGS TWICE. MY MOST RECENT ATTEMPT TO SOLVE THIS PROBLEM WAS TO POLISH THE BOTTOM OF MY ALUMINUM BOAT. THIS HELPED A LITTLE BUT DID NOT CORRECT THE PROBLEM. THIS SAME BOAT AND MOTOR WHEN NEWER WOULD PERFORM GREAT WITH HEAVY PAYLOADS. NOW IT JUST HAS NO GUTS. I AM AT THE END OF MY ROPE...ANY HELP WOULD BE GREATLY APPRECIATED!! ALSO, DOES ANYONE KNOW WHERE I CAN GET A TACH SO I CAN TELL EXACTLY WHAT MY MAXIMUM RPM IS?"
 
Have you put a timing light on

Have you put a timing light on this thing to check timing and to see if it is indeed firing on both cylinders.Will the spark jump a gap of 5/16" or better???????
 
a tiny tach will work on that

a tiny tach will work on that motor
you need a dva and a good VOM to test things out
got the factory service manual?
 
"YES, I KNOW IT'S FIRING B

"YES, I KNOW IT'S FIRING BOTH CYL STRONG WITH A GOOD BLUE SPARK, IT'S NOT MISSING OR SURGING IT JUST HAS NO GUTS, I DO HAVE A FACTORY SERVICE MANUAL, NOT SURE WHAT YOUR CALLING DVA, DIGITAL VOLT/AMP METER? I HAVE ALL THE TEST EQUIP, I NEED, I OWN A AUTOMOTIVE REPAIR SHOP, THANKS FOR YOUR HELP."
 
"DVA, direct voltage adapter

"DVA, direct voltage adapter
you have an oscilloscope then right?
because you are working with a/c volts, not like a car"
 
"Sorry for the all caps,I dide

"Sorry for the all caps,I dident know I was yelling. My wife told me that.So anyway tell me more about this tiny tach. I do have an oscilloscope,also I noticed sunday that after 5 min run at WOT it seemed to slow down even more. After a short stop and idle (1 min) it took off ok.(still no guts) Its almost like carb bowl is refilling at idle,but I get no surge or missfire at WOT like it s starving for gas. I have tested everything that is outlined in service manual and the problem won't go away"
 
tested fuel pressure and vacuu

tested fuel pressure and vacuum?
rebuild the carb with OEM parts?

try running with the cover off

kind of sounds like water in fuel
 
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