Johnson HD-20 Won’t start

[jsonova99]

Yes, the leak is from the low speed venturi when I prime, just a little fuel running down the front out of the whole. I saw the same watching a few YouTube videos of HD20s and 25s running. When I shot the fuel in with the syringe, it very briefly fired, I mean like each cylinder maybe once or just one cylinder. But you could hear it, and get a quick whiff of exhaust. If the low speed needle packing is truly gone in mine though, could this be the problem? How many turns out should I have the low speed needle?

[steveh]

I looked through my photos and I don’t have a pic of the exhaust plate being off. I seem to recall a small brass tube that would direct fuel to the piston on it’s way down, but I might be thinking of another motor. Perhaps Aquasonic will chime in on that topic.

You should be seeing some fuel dripping down the low speed venture if the motor isn’t running if you’re pushing the primer button. At least mine does…it’s open to the air and without the engine running, it won’t suck the fuel in. It’s got to go somewhere.

Initial settings on the needles are about 3/4 turn on the high speed, and about 5/8 turn on the low speed.

[jsonova99]

For the low speed packing, what can I do to recreate what should be there?

[kevinf]

On other motors I’ve used dental floss for replacing the packing.

[burnt-clutch]

quote jsonova99:

For the low speed packing, what can I do to recreate what should be there?

I found out about the low speed packing part for my HD-25 here,

viewtopic.php?f=2&t=3228

I think yours might take the same part number (41-275). I called Sea Way marine last week and they sold me some, fairly cheap.

-Karl

[jsonova99]

I’ll look into that, thanks.

[jsonova99]

Got new low speed packing, the needle is very hard to turn though now, not sure why.

Anyway, using the pull string off an old LT10 right on the flywheel, I can get it to run briefly, a few seconds tops. Just won’t keep going. The block is warm from the few brief runs. Tried priming it when it would catch but doesn’t seem to help.

[kevinf]

Couple more questions? You commented its warm. Are you running it in a barrel or dry? Prop on or off? I’ve had some small singles that are so worn they just don’t seem able to swing a prop particularly if they have a stuck ring or two.
Kev

[jsonova99]

For this, dry. Just wanted to get it to run. Pulls over pretty easy and does have good compression. Reseated the low speed needle and moves easier now. Did get it to run a few seconds longer. once a little warm it seems to catch on almost every pull. There is not much gas in tank, with it leaning forward I’m thinking maybe gas isn’t continuing to flow into the float chamber. When I mean low, it’s low. It is leaking from the primer but does seem to be priming. Going to try adding more gas to see if that helps at all

[jsonova99]

I still think it’s fuel delivery related.

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