Thread: Why do some 2 strokes do this?

Sounds like a flooding issue.

Don't run it dry?

Originally Posted by Slunnie

Sounds like a flooding issue.

Not flooded, can sometimes get it going after 30 mins using the choke.

Was told 45 years ago that the wrong heat range plug was the reason for the same prob.

(had a Pope lawn mower engined chopper mini bike back then that did the same thing).

cheers, DL

Originally Posted by 350RRC

Not flooded, can sometimes get it going after 30 mins using the choke.

Was told 45 years ago that the wrong heat range plug was the reason for the same prob.

(had a Pope lawn mower engined chopper mini bike back then that did the same thing).

cheers, DL

Ahhh,

Have you done a strip on the carby. The other thing that may be happening, depending on the type of carby is:
Check the diaphram for stretching which may prevent pumping if it goes dry
If it has a needle and lever, also check these for wear to make sure that you've got flow and its not leaking.

Likewise its probably worth clearing the mixture jets out too and checking any flap valves for deformation

For the plugs, my experiences are that once they have fouled they will always be problematic even after cleaning. Its worth running a slightly hotter plug if you get fouling. Incorrect fuel mixtures will also do this, particularly on the low speed jet.

Thanks Slunnie.

My sister bought the exact same saw on my recommendation and has the same problem, which is exactly the same as what the Pope lawnmower motor had all those years ago............ before diaphragm carbs were really in wide use.

DL

Originally Posted by 350RRC

Thanks Slunnie.

My sister bought the exact same saw on my recommendation and has the same problem, which is exactly the same as what the Pope lawnmower motor had all those years ago............ before diaphragm carbs were really in wide use.

DL

Oh, is your a diaphram carby?

Well I assume so, same sort of carb as the Stihl has and all the various modified whipper snippers I have.

Can't be a flooding prob because it can be totally run out of fuel........ if cold fill it up, pump the bulb till fuel is obviously flowing back to the tank, choke on, it fires, choke off, will start and idle fine after no more than 2 pulls.

If warm and the above is repeated, forget it.

cheers, DL

That is weird. I normally try to start without priming after refilling firstly and then choke and then prime until it kicks. Stihl is usually pretty easy to start. Always with WOT. Mate, I'm not sure.

It might be worth checking spark too - not near the plug hole in case you ignite.