Hard Pulling Stihl 038 still a mystery

[RES]

After doing a search, I found two other people that had the same problem. However their remedies did not work for me. With the sparkplug removed, the pull rope works fine. As soon as I put the sparkplug back in. It is almost impossible to pull through each compression stroke. I have removed the clutch housing and needle bearing and carbureator. It still pulls hard. The rope looks like new. When I have the rope almost fully extended the last compression stroke is still hard. I have looked through the sparkplug hole. It doesn't look wet inside. What could be causing the problem. The thing that puzzles me is that it happened occasionally in the past and corrected itself.

 

[mattinky]

Any chance bar oil could be getting into the cylinder / crankcase? That'll make 'em pull hard. I'm not that familiar with the 038... just a thought

 

[huskydave]

My best guess (Im fairly certain) is it is flooding and gas is collecting in the crankcase. Flip the saw over and pull the cord with the saw upside down and see if any fuel comes out of the sparkplug hole. The other thing it could be is a loose coil or something else binding. I would take starter assembly off to rule out anything that may be binding with the flywheel.

 

[chowdozer]

With the sparkplug removed, the pull rope works fine.

If you have a compression gauge, check it. If you don't, swing a deal with your dealer and post the results. Someone may have worked on that saw and left out the base gasket/milled the jug... or something. Sounds like you just have a heckuva lot of compression and the question is why.

 

[RES]

Thanks for the advice. No one has worked on the saw. I had it since new. I did turn the saw upside down and cranked it. No flooding was evident. Is carbon buildup a possibility? I will start tearing it down to see if anything is binding.

 

[West Texas]

Before tearing it down, try spraying some fuel on the air filter, like a starter fluid, and see if it will fire and start? Strange as that sounds, I've used that on some saws after rebuilding them, and they kick right over; and, after running awhile, turn it off and they crank normally. :bang:

 

[songercarving]

A cracked rope rotor (pulley) with tend to do that.
Stevie

 

[andrethegiant70]

I second the thought on checking your rewind. The additional pressure you apply to the rewind when the plug is in may be causing it to bind somehow. That would explain the tight cycle right before you run out of rope. End of the rope = more pressure = binding.

The oil in the crankcase I suppose is plausible, but that is far more common on the "laydown cylinder" saws like the 041 and the 051. Oil in the crankcase doesn't so much cause the excessive compression, its when the oil gets up into the cylinder... not quite as likely on an 038. You'd probably have to fill the whole crankcase first. I think you have a small, easy to fix problem. Great saws and worth the effort.

 

[RES]

Mystery solved. I removed all of the panels on the saw, the flywheel and the starter housing. I must have removed 5 pounds of oil soaked sawdust. I think the sawdust packed arount the flywheel may have added some resistance. At any rate I cleaned everything up, rebuilt the oil pump with a new seal, installed an elastostart, rebuilt the carb. The saw is running like new again. Thanks for all the good advice.

 

[teacherman]

Great simple fix!

 

[Wirenut2266]

Again, Top notch repair in the average Joe reair shop

 

[Kenskip1]

A worn starting rope will do this. as the rope wears from years of use it will tend to get thinner to a small degree. As it wears it will look for the easiest way out. In your case the rope was now re spooling sideways instead of vertically. With the plug out their is no resistance and the rope spools normally.I do not think that the sawdust you removed is the true culprit.I would install a new rope, and have a good look at the rewind spool, Ken

 

[RES]

Ken: The 038AV has a nice thick 4.5mm rope that stacks as you rewind it on the spool. In my case it was not worn and the spool was in good shape. I did replace it with an Elastostart. Part of the problem may have been my weakening 68 year old arm.