Continuing the fixing of my brother's Johnson 15hp 2000 J15RSSM (I got the electrical problems fixed, I got the water pump fixed, I solved the water leaking out the head), now onto the next problem:
The engine turns on with the choke closed, I have to quickly take the choke off, then it runs for say 30 seconds and slows down and turns off and won't start again unless you do the exact choke start sequence just described above. It keeps doing the same thing, over and over. I have a clear hose to the carb and can see the fuel flowing, I even pumped the primer bulb to see if it was the fuel pump, made no difference. I tried different ways to make it run longer, and found that when she starts to slow down, if I give it a quick choke on/off then accelerate, it runs good again till it slows down again. If I just accelerate it when it starts to slow down to turn off, it sometimes floods it off and somethimes it speeds it up, like when I give it bursts of speed. The only way to get it to keep working is to give it a quick choke on/off and accelerate.
I had the idle needle set at 2 turns and later 2.5 and 1.5, made no difference. I took out the needle and it looks flat with sharp edges. The attached description and pictures of a new needles shows that the edges are at 10 degree, while mine looks completely flat edged and shiny, could this be the problem? I had taken apart the carb and cleaned all of the passages with hypodermic needle and Isopropyl alcohol through all of the jets and passages and cleaned the bowl and everything, and blew light compressor air through them. Mayne I re-assembled something wrong? Any advice would be greatly appreciated.
The engine turns on with the choke closed, I have to quickly take the choke off, then it runs for say 30 seconds and slows down and turns off and won't start again unless you do the exact choke start sequence just described above. It keeps doing the same thing, over and over. I have a clear hose to the carb and can see the fuel flowing, I even pumped the primer bulb to see if it was the fuel pump, made no difference. I tried different ways to make it run longer, and found that when she starts to slow down, if I give it a quick choke on/off then accelerate, it runs good again till it slows down again. If I just accelerate it when it starts to slow down to turn off, it sometimes floods it off and somethimes it speeds it up, like when I give it bursts of speed. The only way to get it to keep working is to give it a quick choke on/off and accelerate.
I had the idle needle set at 2 turns and later 2.5 and 1.5, made no difference. I took out the needle and it looks flat with sharp edges. The attached description and pictures of a new needles shows that the edges are at 10 degree, while mine looks completely flat edged and shiny, could this be the problem? I had taken apart the carb and cleaned all of the passages with hypodermic needle and Isopropyl alcohol through all of the jets and passages and cleaned the bowl and everything, and blew light compressor air through them. Mayne I re-assembled something wrong? Any advice would be greatly appreciated.
