020t rotor wont turn

[stonerfan]

Just had a new piston and barrel fitted to my 020t. It worked fine for a day or so then went to start it and the pull cord had stuck. Took the cover of and the rotor will only turn one revolution both ways. It sounds like the crank is banging on something. The piston is going up and down with the plug out so wondering if anyone got any ideas before I take it back to the repairer.

Many thanks.

[High Scale]

Will the saw run?

 

Does the pull cord stay stuck out?

[Rich2484]

So is it not turning with the plug in? But turns with the plug out?

[stonerfan]

No the pull cord only comes out about 4 inches once only.(the one revolution) of the rotor and then stays stuck. It doesnt start as its not fully turning over.

The piston goes up and down as to the one revolution with the plug in or out.

Not sure if the new piston/barrel were not fitted correctly or if its just coincidence that its happened directly after the repair. Dont want to lay blame where its not due.

[Rich2484]

Ok. Sorry but going for the simple stuff here.

 

Is there enough pull cord? As in is there any left on the plastic or is the four inches the only amount of cord on it?

 

Remove the starter assembly and check if it's getting stuck off the saw. If it is then look to see if the pawl and flywheel are ok.

[peatff]

If it worked fine for one day it might be unrelated to the work done unless something has come adrift like a little end clip or something. As above and see if it will turn over with a spanner on the flywheel nut.

[stonerfan]

The pull cord is ok.

I took the rotor off the crankshaft end to make sure it wasnt fouling anything. Put the nut back on the shaft and it will only turn with a socket the same amount as with the rotor on.

I was thinking myself it might be the piston circlip come adrift but wouldnt that just fall into the crankcase without fouling the crankshaft?

[Rich2484]

The pull cord is ok.

I took the rotor off the crankshaft end to make sure it wasnt fouling anything. Put the nut back on the shaft and it will only turn with a socket the same amount as with the rotor on.

I was thinking myself it might be the piston circlip come adrift but wouldnt that just fall into the crankcase without fouling the crankshaft?

 

Nope. It will jump into the transfer ports and cause some serious damage. It might go up the top part by the spark plug. And get stuck up there. Could be what the piston is hitting.

 

But with my experience they tend to catch the edge or the piston and cause seriouse damage to it and the rings. This always leads to a new pot and piston.

 

You can either send it back to the shop or a tech on here, or even take the pot off and have a look yourself. Always help on here from variouse people.

[High Scale]

Have you looked at the piston?

[High Scale]

I just thought of something.

 

Is the rotator/magneto located onto the spline of the shaft?

 

There is a slot where it has to be located.

 

If not this could be the reason it worked for a while, if it's not located properly it will move, make a noise and then won't start or run.

Edited March 24, 2014 by High Scale