saw won't turn over unless plug is removed

[meamjw]

I have an Echo saw that is quite old but hasn't been used much. It has a problem I have never encountered before in 50 years of working on small engines; not professionally, but still many. The thing will not turn over unless I remove the plug, then it is as easy as expected. I pulled the cord many times with the plug removed to expel any mixture but as soon as I put the plug back in I can't turn it. I can't imagine what would cause this unless the exhaust is plugged, which I doubt because a mechanic at a shop got it started for a few seconds.

[dougand3]

It's worth removing the muffler to try pulling with the plug in. And then, you can view piston and ring.
Carb needle stuck open and really flooding?

[sawguy21]

With the muffler off check for carbon buildup on the piston. Also check the rewind, if the pulley is worn it may be binding on the compression stroke. BTW, welcome to the forum!

[chet]

Does the saw have the correct reach plug installed?

[sawguy21]

The shop tech was able to start it so the piston did not contact the plug.

[Al_Smith]

It could be nothing but the starter pawls or the drum running eccentric .Real simple to figure out .Pull the starter assembly off and roll it over by hand

[chet]

The shop tech was able to start it so the piston did not contact the plug.

Somehow I missed dat part. Must be dat old age thing creepin' in on me agin.   :D

[Al_Smith]

Okay here's what could happen .The bushing on the starter drum if it has one with some age will wear out ,fall out or  just plain not work .The drum will rattle around like a BB in a boxcar and with compression bind the assembly .It depends on the saw some just use a plastic drum with no bushing.on those it takes another drum which is rather common on a lot of saws because they use the same style .
Some of the older saws that used a metal drum used a nylon bushing which is replaceable some times if you can find one or fabricated if mechanically .inclined otherwise  .I had a bad one on a Husqvarna 2100 CD which is bear to pull over if everything is good on the assembly and nearly impossible if not .I turned a brass bushing for that one that will never wear out in my lifetime .

[joe_indi]

I second Al!
A worn rope rotor wobbling on its axle moves away from the center under compression load and causes a resistance on the rope. If you pull smartly it turns but not otherwise.

[Sluggo]

Hello folks, glad to have found this site.
Am also needing to replace the bushing.
It's got the metal drum and is very wobbly.
Thought old age was the factor, as I could hardly 
pull this saw over.
It also has a muffler with two outlets.

[Real1shepherd]

I've fabricated those bushing sleeves on 2100's from hardware store, drawer stock. Probably nylon, but maybe Teflon....don't remember.

They seem to last longer if you use a dry lubricant on that part of the starter assembly.

OP...definitely check out the entire starter assembly for issues and play.

Kevin

[kenskip1]

How about a worn starter rope. As time marches on the rope will wear. As it wears the rope will wedge itself  further into the pully with the spark plug installed. With the plug in and compression comes into play the rope will tighten, get thinner and wedge itself in the pully, thereby causing this "possible" issue. Another possible cause is a shorten starter rope. As the rope is shortening you will loose all mechanical advantage and it will be hard to pull. I would check for possible cracks in or on the recoil spool. Ken

[Real1shepherd]

Worth checking, since there are over five sizes of starter cord. Could be the wrong size was put it as a replacement and with some wear is wedging itself. I've never found that to be a problem over time if the right size was properly installed in the first place.

Kevin

[Al_Smith]

I'm not certain if this would apply or not . I inherited my dad's old Mac PM 610 that had a replacement recoil .The way that type is made it's held in place with a screw and washer which was too tight and bound up .Plus the spring was under too much tension .You only need about 1 additional wrap on the drum than it takes to fully retract the cord  .Too tight will bind the recoil spring .Just a thought .