Thread: Why do some 2 strokes do this?

I do have a video of a 1974 Evinrude outboard motor, been serviced twice in its life, starting on the second pull after sitting in a shed for 12 years.

Nothing wrong with 2 strokes if one is not of the greeny vegan persuasion.

Also once bought a Seagull outboard that was seized on the main bearings........ bit of lube and mechanical persuasion to free it up and it runs fine, even pumps water.

DL

sticking valve in the pulse pump diaphragm and its vapor locking.

in theory you should be able to get it to restart by operating the primer before you start it you may need to give the primer bulb a push (on the engines that have them) while you pull the cord over then give it a hit to start it.

I think it could be something to do with the whole engine assy being hot and the fuel part of the mixture is evaporating / changing mixture, before it gets to the combustion chamber

there isn't the fuel in the mixture to get a burn and start the process

Originally Posted by Hay Ewe

I think it could be something to do with the whole engine assy being hot and the fuel part of the mixture is evaporating / changing mixture, before it gets to the combustion chamber

there isn't the fuel in the mixture to get a burn and start the process

This is possible as air cooled engines get very hot when they stop especially 2 strokes so after 10 minutes stopped it is probably very hot indeed, too hot to run.
Chris

I used to work for mob called air cooled engines and if I recall correctly the old fella always told clients that it was a sign the mixture was carrying too much oil... I personally don't know enough to argue that point...

I can't explain why it happens, but it's happened to me often, and most often with my small Dolmar saw. The remedy for me is to be aware of the tank level and cut the engine instantly at the first sign it's going to run out. For me, that's a slight rise in engine speed as the fuel line empties and it begins to suck air. For it to work every time you have to be very quick.
Don.

My (Stihl) chainsaw will do the same thing - can be very difficult to start if I let it run out of fuel.

But the issue is not restricted to 2 stroke engines. My lawnmower will do exactly the same thing - and it's a 4 stroke Kubota.

Not very often that I have let the mower run out of juice, but when I do - it's always a good excuse to have a beer ...................

I have a 5 hp 4stroke mulcher that does the same. Starts first or second pull when cold. If you have to shut it down it won't start till it is cold. Otherwise will run all day if needed. Jim