Re: Gray foam(lots) from exhaust outlet 1957 Evinrude 10hp

[Bob Wight]

If you did a lot of low speed trolling it was probably just loading up with fuel – the foam is caused by unburned fuel/oil mix coming out the exhaust which is normal. It can also be thick if there is a lot of old carbon buildup in the cylinders and in the exhaust housing which leaches out with the unburned fuel. BTW, you should be running that motor at a 24:1 mix not 50:1. That vintage of motor also had issues with the wrist pins wearing out (actually the wrist pin holes in the pistons) and some folks even use 16:1 mix to help with that problem.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1957 Evinrude 3022
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20
1982 Evinrude 25hp

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