Stihl MS361C crankcase alignment

[Dan91]

Hi guys and girls

 

Quick question, I'm changing the piston and cylinder barrel on a friend ms361. On removing the cylinder I've noticed there is a discrepancy in heights between the 2 halves of the crankcases, ironically where the cylinder bolts down.

 

The owner has fitted a new "clutch side" crankcase (genuine Stihl) as the clutch drum was ran to thin and proceeded to explode.

 

Does anyone know whether the ms361 crank case halves are fitted with aligning dowels?

 

 

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[njm]

Yes there should be a sleeve fitted in the rear bolt location

[Dan91]

So there is only one alignment dowel? I'll have to loosen all the crankcase bolts and try to manually level the barrel mounting surface best I can without interfering with the crankshaft alignment.

 

I may be making something out of nothing. I measured the height difference between the cases at 5 Thou. I'm concerned that once the barrel bolts are tight the cylinder could be tilted out of line to the crank/piston travel resulting in an increased load and wear on one side of the piston.

 

Crank rotation has a bit more resistance than I'd like but that may be down to the new seal in the case.

 

Worst case I'll have to get the owner to take the saw to a certified dealer to give their opinion. It's not my saw so I'm not going to take a chance then have someone blaming me if it dumps its guts after 10 hours.

 

 

 

 

 

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Edited January 15, 2017 by Dan91

[SawTroll]

I always get worried when I see a Stihl designation with a "C" suffix on it, as it usually means that the saw has some unwanted "feature" on it, possibly the "toolless" chain tensioner in this case?

 

That has nothing to do with the issue at hand though, that's a fairly common issue when one case halv is replaced, regardless of brand. If the cylinder gasket isn't flexible enough to solve it, there is a real issue, and the "higher" side may need to be ground down.

[Stubby]

I think you should fit 2 new crank case halves as they are matched to a degree at the factory . Its what I have heard in the past .

[cornish wood burner]

I think you should fit 2 new crank case halves as they are matched to a degree at the factory . Its what I have heard in the past .

 

I'm surprised the factory didn't even go further than just matching. A light skim would have made it perfect.

Having the bore out of line with the crank can't be good.

[spudulike]

I think you should fit 2 new crank case halves as they are matched to a degree at the factory . Its what I have heard in the past .

 

That is pretty much what I thought as well, it is a difficult one to resolve. You can mount the cylinder over the piston, push lightly on the cylinder top and feel to see if it rocks from side to side when the crank is rotated. That will tell you if the height difference will cause an issue. If you do use it, I would use a liberal coating of liquid gasket around the base both sides of the gasket!

 

I wonder if the dowels were lost on the rebuild:confused1:

[peatff]

I always get worried when I see a Stihl designation with a "C" suffix on it, as it usually means that the saw has some unwanted "feature" on it, possibly the "toolless" chain tensioner in this case?

 

That has nothing to do with the issue at hand though,

 

B is easy chain adjust, E is easy start and Q is quickstop plus. Not sure what the C is for it might be low emission (caring for nature in their write up).

[Daniël Bos]

Think c can mean comfort, but also catalytic converter.

Stihl haven't always been consistent with their naming.

 

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[peatff]

Think c can mean comfort, but also catalytic converter.

Stihl haven't always been consistent with their naming.

 

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I didn't include the cat because they use C for their battery saws, comfort or clean sound like possibilities.