Hello,
I have recently bought a Johnson 9.5 and had a few questions. First, I would like to know the year of this motor. The serial # says MQ-10S, which would make it a 1964, but there are a few discrepancies. After looking around the motor a bit, the numbers on the carb (309726) and some features make it look like it is slightly newer, 1968 from what I gather. Also, the slow idle knob is attached to the carb via a wire/cable. I was under the impression that the earlier motors, '64-'66 had a solid rod that connected the knob to the carb and that the newer ones had this wire/cable. The idle speed adjustment on the side of the tiller, near the gas port, is also tell-tale of the slightly newer motors (newer than '65). I am just not sure if the carb and some parts have been replaced on a 1964 frame/powerhead or if the powerhead/carb are from a '68 and the transom mount (and serial plate) has just been replaced. I have attached some pics if they help at all.
Also, when taking the motor out on the water, I had some problems. It starts first pull every time and runs like a top. I can get it up the 1/2 throttle with no problems, but then it starts to bog and the rpm's fluctuate up and down a little. If I pull the choke out (choke engaged), it then rev's out great, sounds healthy/strong and gets the boat to plane out like a champ. When the choke is pushed in (choke disengaged) it starts to bog again. I have checked the tank and lines and they all seem to be satisfactory. It just seemed weird that it would bog like it is not getting enough fuel, but engaging the choke and giving it less oxygen/more fuel worked well. Just seems to me like it gets plenty of fuel when the choke is engaged, so I kind of discounted clogged fuel lines and faulty fuel pump. It even does this with the hood off, so I have also ruled out an exhaust leak. After a little research, I have come to the conclusion that the high speed needle is the probable culprit. I have ordered a carb rebuild kit and plan to fully clean everything in hopes that this will help. Does any one have any other ideas as to what else may be causing this? Also, it runs great when I pull the choke out and leave it. Will this hurt the motor at all if I continue to do this? Thanks is advance for any help and advice that you may have.
I have recently bought a Johnson 9.5 and had a few questions. First, I would like to know the year of this motor. The serial # says MQ-10S, which would make it a 1964, but there are a few discrepancies. After looking around the motor a bit, the numbers on the carb (309726) and some features make it look like it is slightly newer, 1968 from what I gather. Also, the slow idle knob is attached to the carb via a wire/cable. I was under the impression that the earlier motors, '64-'66 had a solid rod that connected the knob to the carb and that the newer ones had this wire/cable. The idle speed adjustment on the side of the tiller, near the gas port, is also tell-tale of the slightly newer motors (newer than '65). I am just not sure if the carb and some parts have been replaced on a 1964 frame/powerhead or if the powerhead/carb are from a '68 and the transom mount (and serial plate) has just been replaced. I have attached some pics if they help at all.
Also, when taking the motor out on the water, I had some problems. It starts first pull every time and runs like a top. I can get it up the 1/2 throttle with no problems, but then it starts to bog and the rpm's fluctuate up and down a little. If I pull the choke out (choke engaged), it then rev's out great, sounds healthy/strong and gets the boat to plane out like a champ. When the choke is pushed in (choke disengaged) it starts to bog again. I have checked the tank and lines and they all seem to be satisfactory. It just seemed weird that it would bog like it is not getting enough fuel, but engaging the choke and giving it less oxygen/more fuel worked well. Just seems to me like it gets plenty of fuel when the choke is engaged, so I kind of discounted clogged fuel lines and faulty fuel pump. It even does this with the hood off, so I have also ruled out an exhaust leak. After a little research, I have come to the conclusion that the high speed needle is the probable culprit. I have ordered a carb rebuild kit and plan to fully clean everything in hopes that this will help. Does any one have any other ideas as to what else may be causing this? Also, it runs great when I pull the choke out and leave it. Will this hurt the motor at all if I continue to do this? Thanks is advance for any help and advice that you may have.
