Re: Johnson 5hp TD20 ignition timing facts & figures?

[legendre]

quote Jim Moffatt:

Test the carb check valve. It should allow air to pass through one way but not the other,

Check valve seems fine, in that I’ve tried two different parts – one from the carb of my good runner. In fact, I tried the complete carb from the runner as well – same issue, all around.

Primer also works great – and it wouldn’t, with a poor check valve. Likewise, the slow-speed mixture needle has significant influence over the motor, when I’m running it at the lowest speeds possible. That’s the odd part – it displays almost what you’d expect for a ‘low’ idle, when the lever is just slightly below half-setting.. but it gets very rough, very fast, below those settings. Motor reliably dies 1-2 clicks below half-throttle..