stihl 009 chainsaw, chain tensioning problem

[donrkebab]

Hi Guys,
I have owned and used a stihl 009 chainsaw for over 20 years without a problem. But it has recently developed a strange fault that has me stumped. The chain tensioner screw/bolt continuously loosens, used it this afternoon for about 20 minutes. Started off the screw was ok with good chain tension, but it loosened and the chain came off. Anyone any ideas as to what is going on. The problem has never occurred in previous 20 years.

 

[Burnerman]

The chain bar securing bolts (or nuts) may have a stripped thread.....can you check those?
John

 

[Norcon]

Make sure the collar nut is well tightened.
Remember to hold the bar nose up when you tighten the collar nut!

If you've been using the same bar and chain for the last 20 years I would strongly recommend renewing both!
About £60 quid will replace them.

 

[donrkebab]

Thanks guys, I've also noticed the chain sprocket is worn, it has a groove nearly 1mm deep. Some info I found elsewhere said the chain sprocket should be replaced for every two chain replacements, I'm probably on my sixth or seventh chain. So I'm going to replace them both and the bar.

Problem is after searching for the parts (including the clutch removal wrench) I can't them anywhere. Does anyone know of a good stockist of stihl chainsaw spares in the UK?

 

[Burnerman]

Unlike many manufacturers, Stihl parts are readily available from any of their dealers, or if you want pattern stuff then Garden Hire Spares are great - I use them all the time.
I can't place the 009 (old 'un I guess) but the clutch drum is just usually held with an 'E' clip or circlip and it just pulls away. Beneath that is the centrifugal clutch that has a left hand thread but you won't need to take that off.
The wear on the chain sprocket wont affect the tension particularly so I reckon the thread on the securing bolt or nut may be suspect.
My local Stihl dealer is Gustharts, Blagdon - who I guess will do mail order.
Looking at the bar - the groove needs to be central and the tracks on either side of the groove need to wear equally for a straight cut.
John

 

[donrkebab]

Its all getting very strange, I downloaded the stihl 009 service manual, but there are differences between the manual and my saw. For example the manual states that the chain sprocket has 6 teeth mine has 7, and the centrifugal clutch is slightly different. I think these differences are because the manual is for Eurpopean models but my saw is made in the USA. If I google or ebay the part nos all the responses are from USA. Also I bought my saw just after the big storm of 1987?, so its possible that stihl quicky cobbled together some saws in order not miss the sales opportunity.

Anyway I think I've resolved the problem. Last year I cut down a neighbours tree, don't know the species but the wood was extremely hard. And it was impossible to split the logs, even a 2.5 kg log splitting axe had little effect. I suspect the sap from the tree has got into the chain and gummed it up so its lost its flexibility. I soaked it in petrol and wd40 and it now seems ok. So I'll just soldier on with the worn parts.

If anyones interested the service manual is here http://www.worldoftrainz.com/Downloads/Files/Stihl Manuals/009-010-011-012 Service Manual.pdf And this a general guide to chainsaws. http://www.stihllibrary.com/pdf/SharpAdvice061301final.pdf