Johnson QD-19

[Pixelsbyjim]

I recently acquired a johnson QD-19 from a guy for next to nothing. He had it in a collection hanging on his wall that he was getting rid of. I know the most reliable way to check compression is on a warm engine, but what about one that currently doesn't run and hasn't in 20 years. I put a quick squirt of wd-40 in each cylinder and checked the compression and got about 55psi in each. What's a good general guideline to determine if it's worth putting any money into this thing?

 

[Crosbyman]

it is what it is the man said....

check the gearcase for oil... or rusty water that may need some work


just change the impeller and fire it up... you can reverify the compression after it loosens up

if it does not fire up check that you have fire on the plugs if you do clean the carb.

you can do the electricals if symptoms creep up ( no sparks) coils possibly cracked if never changed


http://www.leeroysramblings.com/johnson_QD.htm

 

[Crosbyman]

dig into this red book for te 10hp 1958.... (great motors)

https://bit.ly/2wqMPTb

it has all the info you need and you can print-off sections to a pdf file for safe keeping

 

[Pixelsbyjim]

The coils are most definitely cracked and need replacing. Just wasn't 100% worth starting to put money into with that compression.

 

[racerone]

Remove the wee bypass covers to inspect pistons and rings.----Just 4 screws each.----Covers are on the side of the block.

 

[F_R]

4 main $$-eaters I would check before putting money in a 10hp.

1. Compression. 55 is low

2. Coils. Already checked and need replacement. That could be a good thing (It hasn't been used for many years)

3. Wrist pins. Lots of Pre-1961 10hp have wrist pins beaten loose in the pistons.

4. Pinion bearing in the gearcase. They can't stand water in oil / lack of maintenance.

Great motors if in good condition.