Trying to rebuild my 1100cd with a donor case/crank assembly (also an 1100CD but newer). Because i am having trouble finding parts for an 1100 I decided just to swap everything over to the donor case. Upon installing the piston and cylinder i found that the piston skirt appears to hit the counterweight just before BDC. Same deal with the piston that came off the donor case (weird). Im going to take the C & P off again and make some measurements but is it possible that different years of the 1100 had different stroke lengths? Trying to determine if i need a different piston or if i need to break out the Dremel.
Husky 1100CD piston interference
- Thread starter Ms290man
- Start date
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No mention of change in bore and stroke in 1100s that I'm aware of. 56 x 40, same as 2100. Also, basic crankshaft part number same as 2100.
1100: 50 12 916-01
2100: 50 12 916-61
Applying Occum's razor, is there a chance the donor crankshaft is non-genuine?
I didn’t think so but I will check. The case that I got as the donor doesn’t appear to have ever been separated so I naturally assumed it was a stock crankshaft.
I have heard from others that the AM pistons will indeed hit the counterweights.
Hmmmm, I didn’t think that these were AM but both pistons are very clean. So do I break out the Dremel and take off material to clear the crank or shorten the whole skirt?
That would've been my first theory but the way I read the story, the piston cleared the counterweights on it's original crankshaft but doesn't on the 'donor' saw's crankshaft. More likely 1 out-of-spec crankshaft than 2 out-of-spec pistons.
@Ms290man Do the pistons have 'Mahle' cast into the underside?
No “Mahle” on either piston, see the pics. The one on the left came from the original saw, the right from the donor saw.I did just notice that the original saw has a boss in the case that has been ground down while the donor saw hasn’t. Thinking now that is what the piston is hitting. Thoughts?
Looks like I picked the wrong manufacturer! Both pistons are Karlschmidt, therefore 99.99% sure to be genuine.
Here's my updated theory, assuming there's absolutely no radial play in the big end.
Somewhere in the back of my mind I remember something about having to grind away a piece of casting in order to clear newer pistons, though I honestly can't be sure it was on 2100s.
I'm thinking both pistons are non-original genuine 2100 pistons (Are the cylinders Mahle or KS?) with a longer skirt than 1100 pistons, meaning that some c/case material needs to be removed....but I could be wrong!
Is it better to remove material from the case or would it be better to remove material from the piston? I’m concerned that if I mod the donor case like the original I could wind up with an air leak?Here are the cylinder markings
Mack sure your con rod is not bent
It looks to be straight, no sign of damage or overheating in the bearing areas.
Well, it looks like a Karlschmidt cylinder too.
I'm not experienced in matters of crankcase vs piston material removal. Someone like Huskybill or weimedog may be able to advise.
srcarr52
We can't stop here, this is bat country.
Your donor isn't a 280/380/480 case or crank is it?
srcarr52
We can't stop here, this is bat country.
I can't tell be the serial numbers. The 180/280/380/480 saws look very similar but have 4mm less stroke, 36mm instead of 40mm.
What is wrong with the original 1100 case?
What is wrong with the original 1100 case?
srcarr52
We can't stop here, this is bat country.
The easiest way I could find to tell the difference is the 1100/285/298/2100/2101 case will have the idle speed adjuster screw in the flywheel side case. The 180/280/380/480 will have the idle screw on the carb so there will not be a spot on the case for it.
Er...no. Not easy to confuse 280/380/480 case with 1100/2100 case.
1100 case is bigger in every dimension.
Main bearings, crankshaft, piston pin bearing, clutch, flywheel, etc. The SEM ignition is interchangeable though.
However the most obvious difference is the cylinder/crankcase interface.
1. 280/380/480 cylinder bolts are M4 into captive nuts in the crankcase. 1100/2100 have UNC bolts (like in the pics above) into threaded holes.
2. The 280/380/480 have the transfer port entry outside the cylinder wall, similar to 365/372, only with 2 ports rather than 4.
1100/2100 have the port entry inside the cylinder wall via the open sides of a "powerflow" piston, like 133, 238, 242, 444, 154, 254, 162, 266, 272, 181, 281, etc.
It could only be bent slightly the crank throws come pretty close to the piston on normal operation could be the difference of a few thousands. Measuring from centre to centre on the con rod is the best way, not really practical on chainsaw though.
The original is seriously old!
The bottom mount where the dog attaches is broken off.
Both the old and new case have the idle adjustment screw in the side of the case.
