Husqvarna 266xp not starting

[Khriss]

2 minutes ago, Stubby said:

Bugger indeed !

Its on the way to mums but he would have to fix it over weekend - fr my return journey-   will just  buy new saw 😑**  K

[openspaceman]

On 03/01/2022 at 18:16, sandycb said:

 

 

Any ideas? It's a great saw but have already spent £50 on diagnosis, another £50 on parts so there's a risk of throwing good money after bad. Against that, an equivalent new saw is about £600-£800 I'm told. Help! 

There have been lots of suggestions to try out and I cannot add anything without seeing the saw but I do have a donor 266 with most of the engine bits (mice ate some of the plastic parts as it was put away with vegetable oil in the tank) if you are close.

[spudulike]

120psi is very low. If the saw had come to me, I would have popped the plug out and shone a light down the hole to look at the exhaust side of the bore.

You can remove the exhaust and look at the piston surface through the exhaust port. My reckoning is that you will find some damage on it....scoring and black carbon. 

If you lift the saw with the starter handle, does the saw fall relatively freely to earth or does it fall and stop for a few seconds on each compression stroke? 

Old saws need a pressure and vacuum test, this ensures the LOWER crankcase is sealed by the rubber components and gaskets. The COMPRESSION test shows you secondary compression and gives you an indication on the state of the cylinder, piston and ring.

You firstly need to know you have good secondary compression which means the top end is good, the pressure and vac test is to ensure the machine runs correctly and won't seize with use.

I have seen saws with seals missing still fire and run......badly!

[spudulike]

BTW....where are you based?

And I am not looking for work!!!

[Ratman]

BTW....where are you based?
And I am not looking for work!!!

[emoji16][emoji16][emoji16]

[adw]

did i miss something, i thought he had fitted a new cylinder and piston all be it after market, it is either a crap cylinder, or he broke the ring on rebuilding.

[outonalimb]

Have you tried smearing it with delicious Husqvarna Dipping oil?

I find it very efficacious in most circumstances.

[spudulike]

13 hours ago, adw said:

did i miss something, i thought he had fitted a new cylinder and piston all be it after market, it is either a crap cylinder, or he broke the ring on rebuilding.

Very good Mr A, he did indeed say that he has fitted a new top end. He may have fitted the piston back to front, seen that before! If not, that blokes compression gauge is a bit iffy....unless it was 120 on one pull

[Stubby]

5 hours ago, spudulike said:

Very good Mr A, he did indeed say that he has fitted a new top end. He may have fitted the piston back to front, seen that before! If not, that blokes compression gauge is a bit iffy....unless it was 120 on one pull

Or one for a car ...

[up a tree]

Hard to say without seeing a saw, I agree with key way or cylinder wrong way round, I always start on easy things first Spark, coil, is fuel getting in cylinder, key way could be it maybe not completely broken and moved, then timing is out can not run. First chainsaw build is always the hardest, but great way to learn.