damaged piston/cylinder? husqvarna 254xp

[MartDalb]

Will be 5-10 days wait for new ign. Coil.

 

[wcorey]

Took of the blue wire, at the coil, no spark at all now. (tested by putting it to cylinderhead, no spark) and goes without saying, no ignition either.

Does it have any saying? ^^

Not sure why that should make it fail unless something is flakey with the coil.
The blue wire goes all the way back to the kill switch, yes?
Is the spade connector on the coil loose/wiggly?

 

[MartDalb]

Uhm. I am not up to date at all on electrical things on chainsaws. I just assumed that when you unplug a wire to a start/kill switch it wont fire for sure. That is not the case here? Explain if you can, would really appriciate it.

 

[MartDalb]

Spade connector dont seem loose no.

 

[Mattyo]

All the on off switch does is short spark to ground....so the coil can't generate spark.

 

[MartDalb]

Why was I then told to try with blue wire pulled from coil? Should it have generated spark with blue wire pulled?

 

[Mattyo]

that orange wire looks like its supposed to be attached to ground.... so...that is not the kill wire.

the blue wire is the "kill" wire. if the blue wire gets shorted to ground, it will turn the saw off. ie... thats what the on/off switch does... when you turn the switch off, it shorts that blue wire to ground. if the blue wire is unnattached, then the saw is considered "on" all the time.

 

[MartDalb]

Not according to my coil . Lets hope a new coil helps then.

 

[MartDalb]

And again. Tyvm for the words. /salute

 

[MartDalb]

update.

I put in the new coil, tested, looked good from the testing of spark (more clear spark for sure)

testing the saw, gave me nothing, not a hint of start or anything. STILL not getting anything.

Having had a 254xp (that worked) in hand a few days ago, I am noticing something.

My pull/flywheel is ALOT more rough to pull than the other 254xp, I mean, ALOT harder to pull and not nearly as "freely" moving.
The tip about it having "compression" if it slowly moves down while only holding it by the cord, well that works on the other 254xp, but mine doesn't really move down...it just seems stuck, unless I really help it by lifting/shaking.

So.....can this be a hint of something that might be wrong?

I have nothing to go on from here.....

 

[Adam08ski]

update.

I put in the new coil, tested, looked good from the testing of spark (more clear spark for sure)

testing the saw, gave me nothing, not a hint of start or anything. STILL not getting anything.

Having had a 254xp (that worked) in hand a few days ago, I am noticing something.

My pull/flywheel is ALOT more rough to pull than the other 254xp, I mean, ALOT harder to pull and not nearly as "freely" moving.
The tip about it having "compression" if it slowly moves down while only holding it by the cord, well that works on the other 254xp, but mine doesn't really move down...it just seems stuck, unless I really help it by lifting/shaking.

So.....can this be a hint of something that might be wrong?

I have nothing to go on from here.....

Have you checked the piston after removing the muffler? If it looks good it could still be snagging and scoring somewhere else. Potentially the ends of the ring (intake side, but you will not see it without taking the jug off) Piston ring pin may have come loose. Crank main bearings may be knackered. Small end piston bearing may be knackered. Big end crank bearing may be knackered. Seems like you need to pop the jug off and investigate. Have you got a compression tester or one you could borrow? That would be the easiest way to determine if it is ring damage or not.

 

[MartDalb]

sadly no tester.
I will take it off tommorow and investigate for sure! thanks

 

[MartDalb]

still odd I am not getting a slight pop or nothing,...

 

[Adam08ski]

you won't if you rings are that damaged that they are causing resistance. tbh there are alot of reasons that you can feel resistance and not get a pop. But I think take the jug off as a start..

 

[MartDalb]

Update. Positive one.

I got it to run and pop.

First off. The seal on this right side was not fully in, causing the pull problem i mentioned.


The saw ONLY starts with full throttle hold and gas into plug hole. And it stops as soon as i let go of throttle.
Also noticed I am missing the air duct, is this a problem for starting/running the saw, will buy one asap.

Thanks!!! Yay the sound made me smile

 

[MartDalb]

Second update.

Startet it without gas into plug.

Last problem remains, won't run unless full throttle.
Stops as soon as i let go of it.

Anyone? ☺

 

[Adam08ski]

Here is a workshop manual, may be of use.

 

[Adam08ski]

Here is a 254 series operator manual, go to page 29 and tune your carb following this. It could be that your carb just needs tuning if it is wanting to die. Or you could have a knackered fuel tank breather causing a vacuum..

 

[MartDalb]

Update. It runs. Smoothly.

Startup is rough requires lots of hard pulling, and sometimes the starter robe seems to slip and not catch the flywheel. But IT RUNS!!

THANKS to everyone helping me on this very time consuming project!

 

[Adam08ski]

If you want to go further then I suggest tearing down the carb and resetting the metering lever, might help with starting. The 254 and the others on the case all start very easily in my experience.