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Too lean too rich or just right Johnson 15

jdkline

Regular Contributor
" Hey, I have a 15 HP Johnson,

" Hey, I have a 15 HP Johnson, and it runs great, but sometime, it's been being kind of a hard starter. I just rebuilt the carburetor,a nd it eventually does start once I choke some more and keep cranking the engine. I have recently checked the compression and spark, and the compression was good. The spark jumped the small engine setting on the tester. Unfortunately, it did not have the 7/16" setting recommended for Johnson/Evinrude, so I can't be positive about it. Also, I changed the plugs from NGK to AUtolite, and set the gap at 0.030". What do you think? Could it be running too lean, or am I more likely running it a little rich? "
 
" Jdkline,

If you get


" Jdkline,

If you get it figured out, let me in on it; I've got a 2001 25 HP Johnson that checks out 100% and gives me hell if I let it sit more than a week between starts.. once it is up and going, it's great for a week or so, until I get lazy and leave it again. It's like the carb gets fouled slightly and then clears out after it's run for a minute. It'll do the stupid sputter thing, start and immeadiatly stall, vibrate & sneeze and then after 30 seconds to a minute, purr like a kitten. I haven't actually tried rebuilding the carb yet; doesn't seem like the carb as it runs great at all RPM's, but have done an extensive amount of screwing around with the low speed jet.

With mine anyway, it's still on 25:1 break in gas; the plugs are allways oily, not carboned, just really oil covered. My theory is that it will get better once on 50:1, as the plugs won't allways be fouled... I should try this too - clean the plugs before you start it next time and see if there's a difference. If so, you are probably rich.

Jon "
 
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