Husqvarna 435

[a. palmer jr.]

I have a Husqvarna 435 that was brought to me with low compression. I took it apart and noticed it had a stuck ring but the piston and cylinder looked otherwise undamaged. I pried the ring off, cleaned the ring groove out and replaced it with a new Caber plus replacing all the seals and using Dirko on the crankcase halves. I got it all back together and gassed it up and it wouldn't run but for about 2 or 3 seconds and then it would die. I taped the throttle wide open and it still wouldn't keep running. I've replaced the spark plug , the fuel is unleaded plus no ethanol, 40:1. Spark looks okay, wondering if I should spring for a new carburetor...I tried adjusting the carb on both screws from about one turn to one and a half, don't know what it's supposed to be set at..

 

[Ozhoo]

435's are 2-1/2 on the low side and 2 on the high side. Give that a shot and see how it responds.

 

[a. palmer jr.]

435's are 2-1/2 on the low side and 2 on the high side. Give that a shot and see how it responds.

Thanks, I'll give it a shot...

 

[a. palmer jr.]

Okay, I went out and adjusted the carb to the settings you suggested and, although it starts easier it only runs for about 2 to 3 seconds and dies. I tried 1/2 turn on both screws in and out and it doesn't make much difference, still runs a bit and dies. I didn't notice when I had it apart whether or not it has an impulse hose or passage. I guess it's possible also that the coil might be intermittent, so right now I'm not sure which way to go...

 

[Ozhoo]

you didn't use any dirko on the intake flange did you? It would be possible to block the impulse passage doing that.

My next thought would be to disassemble the carb to check that the diaphragms/gaskets are in the correct order.

 

[a. palmer jr.]

you didn't use any dirko on the intake flange did you? It would be possible to block the impulse passage doing that.

My next thought would be to disassemble the carb to check that the diaphragms/gaskets are in the correct order.
View attachment 973886

No, I didn't use anything on the flange. I'm guessing the carb just needs cleaned and rebuilt. I don't know if the carb has ever been apart. If I work on it anymore I'll probably just get a new carb after I check the impulse passage. I took it back to the owner, all I was to do was rebuild the cylinder and re-seal the crankcase which I did..

 

[Tomos770]

Is your saw leaking gas if you put it sideways?

 

[Captain Bruce]

Carb. diagram is a google search, with the part #???

you didn't use any dirko on the intake flange did you? It would be possible to block the impulse passage doing that.

My next thought would be to disassemble the carb to check that the diaphragms/gaskets are in the correct order.
View attachment 973886

????

 

[Ozhoo]

Carb. diagram is a google search, with the part #???

????

Service manual

 

[Tomos770]

Do you maybe have SM for 450?

 

[Toyman]

No expert, but I do have a 435 that had the same issue. It would fire for a second or two and then die. After a little research I found that it could be the ignition module. I replaced it last fall and it's been running excellent since. It also eliminated its hot start issue. Mine is a 435 e II and the PN for the ignition module for mine was 579638804. Good luck!

 

[Tomos770]

Watch out with these CDIs.....they are not interchangable between mk1 and mk2 models.....better to look out trough proper IPL for particular saw (MY and (sub)version)!

 

[a. palmer jr.]

Watch out with these CDIs.....they are not interchangable between mk1 and mk2 models.....better to look out trough proper IPL for particular saw (MY and (sub)version)!

How do you tell which one you have, is it marked on the saw somewhere?

 

[Tomos770]

https://www.partstree.com/categories/chainsaws/husqvarna/?page=2

 

[2StrokeFondler]

Did you double check the distance between ignition module and flywheel? Had a similar problem, and the coil must have been gotten loose somehow on my saw.

 

[a. palmer jr.]

Did you double check the distance between ignition module and flywheel? Had a similar problem, and the coil must have been gotten loose somehow on my saw.

I had the coil off when I cleaned the saw but put it back using the usual business card..

 

[a. palmer jr.]

I think I stumbled onto a new, or maybe the same problem: While trying to rev up the saw with the top cover off I noticed the screw coming loose on the coil. I tightened it up and checked the gap, which was okay but while turning the flywheel it felt like it had a really rough crank bearing. I'm wondering now if that bad bearing might make it not run very long before dying. Shaking the flywheel I can't tell that the bearing is really loose, just noisy..

I also took the carburetor off and checked the impulse passage with some flexible wire and the passage was clear. At this point I may be looking at another teardown...

 

[Tomos770]

Change those bearings with New ones asap...before they will damage (plastic) seat!

I think they are 6201 bearings...try to find them in C3 tolerance! (skf ina etc)

 

[a. palmer jr.]

Change those bearings with New ones asap...before they will damage (plastic) seat!

I think they are 6201 bearings...try to find them in C3 tolerance! (skf ina etc)

Gonna ask the owner tomorrow how much he wants to put into the saw, guessing he will say to fix it as cheap as possible.. should have changed them when I had it apart but they didn't seem too bad until I got it back together and turned it over a few times..

 

[Tomos770]

Bearing of 6201 size is...4-5 euros/piece.....dunno how much you value your time/hands...