husqy 435 crankcase compression?

[Aicchalmers]

I've got a husqy 435, got it used a few months ago and had very little use, barely anything on the sprocket etc. Worked fine for a few weeks and now it's not working.

It'll start fine, sometimes with a bit of difficulty. It will run for up to 5 minutes and suddenly stop. Any attempt afterwards while it's hot it might run for 20 seconds after being on choke but no more. Seems to be a heat related issue.

Everything looks fine, it's still got compression, piston and pot aren't scratched, ignition 'seems' ok..

Is there anything common to go wrong on these saws or where to look next?

Don't really have loads of use for the saw but it'd be good to get it working! Might sell it and get a 550/261 instead

[adw]

Yes ignition units.

[spudulike]

The fact it will restart on full choke leads me to think either the tank breather is blocked or there is a fuel issue such as the blocked carb internal strainer or simply the carb needs adjusting by someone who knows what they are doing.

 

Check the spark when the saw is hot but is sounds fuel related if it will sort of run a bit when hot and restarted!

[adw]

Don't mean to be rude Spud but the ignition unit seems to have all sorts of issues, which can fool you into thinking its other issues, just my opinion, by all means try the easy cheap stuff first.

[Aicchalmers]

The fact it will restart on full choke leads me to think either the tank breather is blocked or there is a fuel issue such as the blocked carb internal strainer or simply the carb needs adjusting by someone who knows what they are doing.

 

Check the spark when the saw is hot but is sounds fuel related if it will sort of run a bit when hot and restarted!

 

It won't restart on choke but after it, sounds like a fuel issue. I thought it could be the tank breather but checked it and cleaned it and absolutely no different, even tried it without it and no difference.

Checked it with a tach and until cutting out rpm is within spec..

Must say I've not pulled the carb apart yet, could this be an issue with heat? Probably worth a shot..

Pull out the plug and turn over, spark would look weak/inconsistent if any issues?

[spudulike]

Don't mean to be rude Spud but the ignition unit seems to have all sorts of issues, which can fool you into thinking its other issues, just my opinion, by all means try the easy cheap stuff first.

 

It may be the way I am reading the OPs original post. If the saw is running for a period of time and then it dies and the only way to revive it is to let it cool down then I would 100% agree with what you say, obviously you know what is what and if these machines have dodgy coils............!!

 

I read or understood from the post that it that it would start again after failing immediaely with a bit of choke and then die again but may be wrong hence my comments - you could try the redneck coil test - take an old plug, open up the end electrode so it is bent out at 45 degrees and then test the spark on the saw when warm - if it sparks then the coil is probably good.....otherwise just swap the coil over and see if it cures the problem, only issue there is if the original fault hasn't gone away, you have just done a bit of wedge:thumbdown:

 

Not knocking your knowledge and no, not taking you to be rude either:thumbup:

[Aicchalmers]

To be clear If I try and start it up again after dieing;

Pull over a few times more than usual on choke it'll sputter as usual.

Take choke off and pull over and it will run for more or less 20 seconds then die again.

So just to check that the symptoms wouldn't match up with crankcase compression e.g perished oil seals?

Likely to be ignition or carb issues?

[adw]

They do not suffer with crank seal issues, is this machine still under warranty? it was a 2 year warranty if the dealer registered it.