I PURCHASED A 1972 JOHNSON 9.5 HP OUTBOARD THAT STARTS AND RUNS WELL, BUT IT WILL NOT HIT HIGH RPM'S. THE THROTTLE GOES ALL THE WAY UP, BUT THE MOTOR ONLY GOES A LITTLE BIT FASTER. I HAVE A 14' JON BOAT THAT WILL ONLY MOVE AT A CRAWL...CAN SOMEONE PLEASE TELL ME WHAT THE PROBLEM IS?
2006-08-30 06:12:35 · 3 answers · asked by phluff_daddy 1 in Cars & Transportation ➔ Boats & Boating
you may have to adjust the carburetor to the altitude of the lake or water. Especially if it is a 2 cycle the altitude will effect the rpms that your motor will pull. Also you may consider a new jet kit to your altitude. I don't know if you have a fuel filter, but if your particular motor has one, your fuel pump may have enough to pull the gas at lower rpms, but not higher. Hope that helps.
Owner of a 25ft sailboat with a 6hp Johnson
2006-08-30 12:28:08 · answer #1 · answered by Ivan the Terrible 2 · 1⤊ 1⤋
A quick check you can do to check to see if it is fuel starvation is to mist fuel in the carb (carb cleaner works) and see if the rpms increase. Clogged carb circuits, fouled plugs, maladjusted settings, and bad fuel pumps is where to start. The pump may not be able to keep up with the higher demand of fuel at wot (wide open throttle). Did the engine sit for a long time? If misting fuel doesn't increase the rpms, then I would check spark and compression. I highly dont this would be a propping issue on a 14 ft john boat.
2006-08-31 00:24:33 · answer #2 · answered by Boat Tech 4 · 2⤊ 0⤋
Yes, you have to adjust the high speed on your carburator. Start with turning to close, but do not force it (gently). Turn it back about 3/4 a turn to start with, then slowly turn either way to get the motor to run smoothly.
2006-08-30 16:48:05 · answer #3 · answered by scrappypapa754 2 · 0⤊ 0⤋