Re: Johnson HD-20 Won’t start

[jsonova99]

As far as I can tell, once running, when the rpms settle down and it appears stable, it’s very sensitive to adjusting the low speed needle. I can hear the engine sucking air in at the low speed Venturi as well.

I replaced the low speed packing, but not sure if I did it right, is it just one small gasket?

I tried starting up dry again today after poking through the high speed jet with some fine wire, that was the only passage I had initially missed. Not sure why that would have done anything, based on the fact that the issue seems to be low speed related but I shot some carb cleaner up through the high speed access on the bottom and watched it shoot out of the jet so that passage is clear. I also verified fuel through here by adjusting the high speed needle and watching fuel drip out or stream out when opening the high speed needle. The carb itself seems to be fine at this point other than the leaky primer washers.

Anyway, it now starts on the first pull cold with both needles set at 3/4 of a turn out. I did notice though that this time once the carb filled and I had primed it, there was fuel dripping from the high speed jet. Other than the leaky primer, I’ve had no leaks.

Once running though it again wanted to race up to high rpm before settling down. I

Going back to the low speed, will these engines run with the high speed needle closed completely? Trying to think of a way to really isolate the low speed.