Sachs Dolmar 123 pull start unit issue

[David Heaf]

Today the pull start on my 40+ year old Sachs Dolmar 123 failed. The rope stayed out after starting but retracted due to vibration when the saw was cutting at speed. This means the spring is working. After removing the unit and testing pull/retraction I can see that the rim of the inner side of the pulley (the outermost when on the saw) is rubbing on the spring in the region of the blue arrow shown in the photo. When pulled, the rope stays out only when pulled to its full extent, but can be retracted by turning the pulley manually.

 

A coil of the spring appears to be dislocated. I've so far hesitated to dismantle further because the spring can 'explode'. Has anyone here got any diagnostic suggestions. I've ordered a replacement spring (# 123 163 010) in case the spring is the cause.

[pleasant]

22 minutes ago, David Heaf said:

The rope stayed out after starting but retracted due to vibration when the saw was cutting at speed. This means the spring is working

No it doesn't. It simply means the spring has lost a degree of its original tension to retract the rope. If this is a sudden difference in performance, I would suggest the spring is the issue. Springs can break in the centre of the winding, which is difficult to see once wound up in the housing, and means only a fraction of the spring is being used to retract the rope and handle. I would remove the recoil handle and allow the rope to lose all tension. Then lay the recoil housing flat, remove the circlip retaining the pulley. Lift the pulley up cleanly and slowly, whilst also checking the tail of the spring isn't caught in the pulley as you are removing it. Put on a pair of safety glasses or goggles whilst doing this to be safe.

[ChrisNewport]

Put the circlip in your pocket before you remove the pulley as if you place it on the bench whilst your working the spring has a habit of flying about in all directions and swiping the circlip off the bench never to be seen again.

[David Heaf]

Thanks Dan & Chris! I followed Dan's instructions and all went smoothly (the circlip was safely in another room when the spring 'exploded'). But the spring itself turned out OK. The pulley side against the spring is sound. In short there's no obvious reason why one turn of the spring was displaced enough to impede the pulley. Anyway, I'll renew the spring when I reassemble.

On the rare occasions that I return to this forum, I always find it very helpful including being able to buy a spare Sachs Dolmar 123 from a member. (It's still running well Steve!)

[pleasant]

Dan & Chris?? Did you mean me OP?

[spudulike]

3 hours ago, David Heaf said:

Thanks Dan & Chris! I followed Dan's instructions and all went smoothly (the circlip was safely in another room when the spring 'exploded'). But the spring itself turned out OK. The pulley side against the spring is sound. In short there's no obvious reason why one turn of the spring was displaced enough to impede the pulley. Anyway, I'll renew the spring when I reassemble.

On the rare occasions that I return to this forum, I always find it very helpful including being able to buy a spare Sachs Dolmar 123 from a member. (It's still running well Steve!)

Was that one I sold you.....Christ, that was a long time ago if so. Glad it is still popping if it is.

If the spring is OK, use a craft knife to clean the gunk on each side, clean with WD40 and refit USING SAFETY GLASSES. Generally feed the spring in from either side of the cover using your thumbs to hold the spring in place whilst rotating the cover.....it is possible.

Sometimes the spring gets a bit gunked up and the pull start gets a bit lethargic.

[David Heaf]

2 hours ago, spudulike said:

Was that one I sold you.....Christ, that was a long time ago if so. Glad it is still popping if it is.

 

It is indeed! It's as powerful as the one I bought in the early 1980s, which is the one with the failed pull start. Thanks for the repair tip.

 

2 hours ago, pleasant said:

Dan & Chris?? Did you mean me OP?

I meant 'pleasant'. I misread the author name. So thanks again!