Weak MS180 Construction

[blsnelling]

Not trying to be a smart a$$, but were you turning it the right direction??

Piston #1 looks to me like you had the piston stop in the center of the piston rather that on the edge. The center of a piston is pretty weak!!

I was waiting for that question. Yes, I was turning it clockwise to remove the clutch. I used a plastic piston stop on the broken piston. I guess that's a no-no on an angles plug hole. The crown of the piston was SUPER thin. There's a measurement in the original thread.

 

[stihl only]

I was waiting for that question. I used a plastic piston stop on the broken piston. I guess that's a no-no on an angles plug hole.

Plastic is fine on an angled plug engine as the stop goes between the top of the combustion chamber and the piston. The trick is to make sure it is all the way against the cylinder wall and make sure you didn't stick it out a port! The problem with the metal ones on an angled plug is, well, the angle!

You got me stumped on this one but unless someone turns up with a free crank for you, looks like a parts saw.

Have some patience as I'm sure there is one out there not worth fixing that someone ran straight gas in!

 

[stihl only]

Guess I should have been more specific on this. NOT a threaded plastic one, but the spoon type that you feed through the plug hole.

 

[blsnelling]

Guess I should have been more specific on this. NOT a threaded plastic one, but the spoon type that you feed through the plug hole.

I haven't seen one of those. Mine is the threaded kind and is why it was in the middle of the crown.

 

[stihl only]

Stihl PN 0000 893 5903. Should be about a buck. They come with the MS200 and MS192 for clutch removal, but also fit a lot of saws.

It is just a plastic double ended deal and the stops are on each end at an angle so you can feed it through the plug hole and hold it against the cylinder wall.

 

[blsnelling]

Excellent. Thanks for the tip. That should be a lot easier to use than a rope and safer than the scew in stop. Unfortunately I don't think it would have helped in this case. I think an impact wrench would have been the safest method in this case.

 

[Urbicide]

And you can see how the connecting rod was obviously shot-peened for extra torsional strength...

Looks like it needed an additional row or two.........:chainsawguy:<-----Brad

 

[brages]

Yes and it weighs the same as the MS180 at 8.8 lbs. The 401 has a very impressive power to weight ratio and it's build like a professional saw.

Is the listed weight for the 401 correct? Apparently, Dolmar has been known to fudge a little...

The 401 looks like a nice little saw, lightweight with some power, reasonable price and quality construction

 

[mtfallsmikey]

I really learned something today!...Thanks Brad!
:jawdrop:

 

[Fastcast]

Is the listed weight for the 401 correct? Apparently, Dolmar has been known to fudge a little...

The 401 looks like a nice little saw, lightweight with some power, reasonable price and quality construction

Just did an unscientific test....On a digital scale, weigh myself, pick up 401 with 14" B&C and full fuel & oil, weigh it.....The 401 holds 13.3oz fuel & 8oz oil.

Me 185lbs.....me with saw 196lbs......Total weight of saw, ready to cut 11lbs.

This is how I gestimate packages I ship with USPS & UPS....always seems to be within 1/2lb of their scales.....Close enough!

 

[blsnelling]

I really learned something today!...Thanks Brad!
:jawdrop:

Sorry I had to give the lesson. to self. I can't find a crank.

 

[DMShaver]

Possible good crank

Brad...I took a seized MS180 in on trade a few weeks ago. I have not looked at it in depth, but did try to hammer the piston down to release it. I ended up with a piston that looks similar to the one in which you used the plastic stop.

I will tear the bottom end off it tonight and see what the crank looks like. I suppose it's possible if the rod is as weak as it appears to be, that when this saw seized it may have bent the rod as well.

 

[bump_r]

It''ll bend back during the reassembly torque-down, won't it?

 

[blsnelling]

That would be awesome and I really appreciate your time and effort. Hopefully the hammer didn't hurt the rod, now that we know how weak they are.

 

[stipes]

Thanks Brad...

Wow!! Didnt realize how easy you can bend that....I kinda got a tounge lashing quite awhiles back about using a impact,,but now,,I rather blow a clutch apart instead of bendin a rod....

 

[blsnelling]

The 401 looks like a nice little saw, lightweight with some power, reasonable price and quality construction

Advertised weights of the two saws are identical at 8.8 lbs. The only problem I have with the 410 is it only turns 12K RPMs. Of course it's constructed like a Pro Stihl saw with vertically split magnesium case halves and a bolt on cylinder, so porting and squish adjustment should not be a problem. Hmmmm.

 

[Urbicide]

I haven't seen one of those. Mine is the threaded kind and is why it was in the middle of the crown.

Stihl PN 0000 893 5903. Should be about a buck. They come with the MS200 and MS192 for clutch removal, but also fit a lot of saws.

It is just a plastic double ended deal and the stops are on each end at an angle so you can feed it through the plug hole and hold it against the cylinder wall.

One of those piston stops comes with the ring compressor set that Bailey's carries.

http://www.baileysonline.com/itemdetail.asp?item=10429&catID=93

 

[blsnelling]

One of those piston stops comes with the ring compressor set that Bailey's carries.

http://www.baileysonline.com/itemdetail.asp?item=10429&catID=93

LOL. I wondered what that was for. I wonder if I still have it.

 

[Urbicide]

Advertised weights of the two saws are identical at 8.8 lbs. The only problem I have with the 410 is it only turns 12K RPMs. Of course it's constructed like a Pro Stihl saw with vertically split magnesium case halves and a bolt on cylinder, so porting and squish adjustment should not be a problem. Hmmmm.

Hmmmm? I'm wondering if there is going to be a run on 401's now.

 

[Urbicide]

I was looking at Makitas. Is the DCS-34 the equivalent of the Dolmar replacement for the 401? Some cut & paste info. Where is SawTroll?

DCS-34

Features
Rugged cast cylinder
Low noise operation
Easy maintenance
Double air filtration
Efficient cold weather operation
High power-to-weight ratio
Specs
Engine: 2.0 cu.in.
Displacement: 33 cc.
Max. engine speed
> > (w/bar & chain): 12,200 RPM
Power rating: 1.4kW/1.9 BHP
Fuel tank capacity: 13.3 oz.
Oil tank capacity: 8.5 oz.
Standard guide bar: 14"
Chain Pitch: 3/8"
Chain Gauge: .050"
Net weight (dry w/o bar & chain): 8.2 lbs.
Shipping Weight: 22.00 lbs.