Reply To: Johnson TD Project

[Buccaneer]

PAUL PENDERY wrote:

I have a Johnson TD20 and spent a good deal of time on it this last year. Solved spark and carburetor issues (I think) but still can’t run it at low speed. Found compression is only at a little over 60 PSI in both cylinders. Is the most likely answer for inability to run at idle speed then the low PSI, and thus at least a ring job? Is there any chance it could be the low speed jet is clogged and low PSI is ok? One more bit of info, The motor seems to react accordingly to adjustments in the setting on the low and high speed valves.

Thanks!

My best idlers in the TD and HD series Johnson are the ones with the compression
close to, or above 70 psi compression. Doesn’t sound like your low speed circuit
is plugged. A ring job may help, depending on the overall condition of the cylinders,
pistons, etc. Make sure your current rings aren’t froze in their grooves first.

Prepare to be boarded!