I was excited about my new Holzforma 070...

[TBS]

I'd just put it back together and torque that nut down properly so that tapered shim gets set in. Make sure you have the washers in place.

 

[SEAM]

If I remember correctly, the 070/090 (and also the Contras) have a bush in the clutch center that deforms when the nut is tightened, locking the clutch on the shaft. If the nut gets loos, the clutch will turn freely on the shaft. Make sure the nut gets tightened properly (and stays that way) or get a new clutch assy with nut...

 

[Justsaws]

Clutch has a tapered spacer between it and the flat side of the crankshaft. It is a press fit held in place with a nut. If there is a washer, anywhere in the mix between the side of the clutch and the nut that holds the clutch on, check them over carefully for being deformed, holes elongated, or mis shaped. The metal used is too soft and the washers give a bit when that happens the press fit becomes to loose and the clutch will spin on the shaft. It is a good idea to replace all of the washers, spacers on that side of the saw.

Replace the washers with a decent quality washer. Reassemble, lightly tap clutch assembly into place, torque down nut.

The washers being too soft is a problem on any farm tec, whatever brand aftermarket clutch set up I have seen.

Replace the washers and the 070 clones can solid performers. Only other common short fall I have seen might be the oiler pumps being a bit meager, hit and miss on those, some pump waaaaaay better than others.

I changed the description of the crankshaft. The crankshaft is not tapered, it is two steps, both flat.

 

[macstrange]

Great info. Thanks. Thanks to everyone who replied.

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[Mad Professor]

huummm chinesium............

Bleach anything new coming from China, so you don't get sick.

 

[atpchas]

From the 070, 090 shop manual:

 

[Modifiedmark]

If you need it, I had a used OEM 070 clutch in the trading post cheap that nobody showed any interest in.

 

[macstrange]

From the 070, 090 shop manual:
View attachment 794421

Are you trying to tell me I should go through the engine and check all the bolts? [emoji1]

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[atpchas]

Are you trying to tell me I should go through the engine and check all the bolts? [emoji1]

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No, but I think you knew that.
Thought it might help to know what torque Stihl specifies to keep the crankshaft nuts snugged down. Much less and things loosen up, much more and threads get trashed or parts break.

 

[Mad Professor]

No, but I think you knew that.
Thought it might help to know what torque Stihl specifies to keep the crankshaft nuts snugged down. Much less and things loosen up, much more and threads get trashed or parts break.

But does chinesium take those torques?

 

[atpchas]

But does chinesium take those torques?

That is the $64 question and the main reason I posted the specs.

 

[Justsaws]

From the side of the crankcase...

washer, clutch drum, bearing in drum. Not usually a problem, if damaged replace.

Washer, inside of clutch drum between clutch and drum. Problem washer, might need replaced.

clutch, taper small hole facing the crankcase, large hole facing out, ridge on the spider facing out. Insert pressed in from end of crank.

small dia. thick washer on top of clutch, tapered insert. Problem washer, might need replaced.

big domed washer. Problem washer, might need replaced.

left handed nut.

There are good videos on YouTube dealing with assembly and repair on the 070 clones.

 

[arto_wa]

That is the $64 question and the main reason I posted the specs.

I can confirm it did just fine in the MS660 clone I assembled in December.
Everything was torqued to OEM specs.

As a side note: One should pay attention to whether the specs are for dry or lubricated threads and if there is no mention of it, the default is: Non-lubricated.
Easy to search and find tables showing the difference.

 

[atpchas]

I can confirm it did just fine in the MS660 clone I assembled in December.
Everything was torqued to OEM specs.

That's an encouraging bit of information but in my experience Chinese parts have been less than consistent in quality. In any event, I gave the spec so the OP would have a torque figure to shoot for in case he didn't have the spec (assuming he has a torque wrench).

 

[macstrange]

Pics of damage

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[macstrange]

If you need it, I had a used OEM 070 clutch in the trading post cheap that nobody showed any interest in.

Might take you up on that.


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[Justsaws]

Yep, that one spun a lot. Clean up the crank and see about getting a new taper bushing, or just clean the one you got up. Check the washers and clutch drum bearing.

 

[Modifiedmark]

Might take you up on that.


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Mine is just the clutch, no bushing with it. I know its good, I took it off a saw for a guy who was putting a very long bar on and I switched it to a 090 clutch.

 

[macstrange]

I sent pics to holzfforma. They offered a partial refund if I could fix it myself. I told them I could fix it, but I would need a clutch assembly with bushing and a crankshaft. They seemed agreeable but said they couldn't ship right now because of the Corona virus epidemic. Apparently they are shut down until government notice.

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[macstrange]

If anyone had a tapered bushing, let me know.
Thanks

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