2 stroke exhaust port carbon blockage question

[Jay Lutz]

Not being very familiar with 2 strokes I thought I'd ask some experts:

What symptoms would I expect to see from a semi blocked exhaust port? I'd expect low power but what about idling quality, throttle pickup, need for choke or not, vacuum generation in intake manifold, starting ability, drivability in general. To the best of my knowledge this 2 stroke has never been manually cleaned out in 30 years. Thoughts??

 

[johnneilson]

Just from the age and lack of care, probably leaking seals more than anything.

J

 

[R. J. Sorensen]

Jay,

Very old LawnBoy mower requires cleaning exhaust ports every 3-4 years. Usually only center (of 3) is plugged.

Biggest symptom is huge loss of power (over time); very slow to recover RPM; somewhat hard to start.

Shutting off gas every use and letting run dry (lean) helps to burn off carbon. Doesn't help after it has built up very thick or already plugged a port.

Not hard to do: remove exhaust manifold and ports should be visible. Use wood (popsicle sticks) or plastic (plastic tableware) to avoid scratching aluminum piston; keep piston mid stroke so carbon chunks don't fall into combustion chamber or crankcase.

Immediate and dramatic difference.

RJS

 

[Jay Lutz]

My lawnboy did the same thing.....I used popsicle sticks 15 years ago. What about other symptoms?