saw maintenance Jonsered 630 brake trips all time

[BEEMAN]

I have an old but very useful Jonsered 630, but the brake keeps coming on at the slightest bump. Very inconvenient, actually it makes the saw more or less unusable. Any ideas out there??

 

Also the saw is a bit low on power..... It has an 18" bar and I have to reduce the load to prevent stalling. I keep the air filter clear - power drops off if it is clogged - but am wondering if a new cylinder and rings might be needed??

[Conor Wright]

Inertia brake worn or packed with dirt maybe? Could also be why it's down on power a bit, if you're not familiar with saw maintenance I wouldn't go playing with the brake, just saying.. if you're mechanically minded give it a good clean out, replace anything worn or damaged and reassemble.. cant really give anymore advice than that as I'm not familiar with jonsereds at all, somebody better informed will probably be along shortly.

L and s engineers are good for parts for most makes.

[adw]

Depends on which brake you have, post some pictures, there were a few different brakes.

[adw]

If its the full inertia brake, then there is dirt under the knee link, this is stopping it from going over centre, strip and clean is the way forward, be aware there is a large compression spring under the cover.

[BEEMAN]

great, thanks for the tips. I will strip it down and clean under the knee as suggested. the drawing is very helpful. I will be careful with the spring! It is a bit heavy, but a good useful saw, when all in order.

[ESS]

I notice you mention the saw is bogging down also.  Its worth checking the av rubbers for excessive play , the chain brake tripping and bogging down could be linked to this.

[woody paul]

2 hours ago, BEEMAN said:

great, thanks for the tips. I will strip it down and clean under the knee as suggested. the drawing is very helpful. I will be careful with the spring! It is a bit heavy, but a good useful saw, when all in order.

Great saw of its time, 

Parts are not easy to get hold of.. 

[gary112]

7 minutes ago, woody paul said:

Great saw of its time, 

Parts are not easy to get hold of.. 

I still got one,but the threads have gone in the pot where exhaust bolts on,otherwise goes great

[spudulike]

BTW, when ADW talks of a "Large Compression Spring", he basically means that if you prize it out, it will explode out of the cover like one of those Aliens out of John Hurt in the film Aliens. Best cover in rag before prizing and only remove it if you need to as it will be a fecker to return in to whence it came from....be warned!

Edited December 29, 2019 by spudulike

[adw]

5 hours ago, gary112 said:

I still got one,but the threads have gone in the pot where exhaust bolts on,otherwise goes great

The 630 was the Husqvarna 162se, the muffler studs on the early cylinder was m5, the later cylinder is m6 using a stepped stud, so if it was m5 then tap out to m6 and use the later m6 stepped stud, just a thought.