Husqvarna 435 chainsaw won't start when warm

[DrRoughneck]

Chainsaw starts on first pull when cold.
After idling a bit, if I kill it and try to start it again, it never starts.
It only starts again when it is cold again 2 hours later.

In general when a 2stroke refuses to start warm, is it a known symptom of something?

 

[Chris B.]

I had the same issue with a Husqvarna chainsaw and they were never able to fix it under warranty. Got my money back and got a Stihl. I'd advise you to do the same.

 

[robshelton]

All the new 2 stroke power equipment is set to idle very and I mean dangerously lean. I work on a lot of small engines as a hobby and usually one of the first things I do is pull the carb and "Defeat" the limiter screws. Many of the caps can be pulled off the mixture screws and reinstalled after you get it adjusted. But on some, I take some small diagonal cutters and snip off the nub that keeps the screw from turning.

Other things you should check are:
Spark - should be a nice blue color
Fuel tank vent
Fuel filter - on the gas line in the tank
Fuel screen in the carb
Fuel needle adjustment in the carb

A quick search found this page: http://www.arboristsite.com/community/threads/husky-435-starting-problems.102175/
The last post is a guy that richened his idle mix screw 1/4 turn and it fixed his hot start problem. The tools are available on flea bay, BTW. Good luck!

EDIT After I looked at the IPL the saw probably has a "Stratified charge" engine. They appear to have two throttles but one is just for air. If so the intake "Pipe" is plastic and usually will not re-seal if you remove the carb. I have a 455 Rancher on the bench right now waiting to see what the owner wants to do. Needs the intake-large air leak.

 

[DrRoughneck]

Originally Posted By: robshelton
All the new 2 stroke power equipment is set to idle very and I mean dangerously lean. I work on a lot of small engines as a hobby and usually one of the first things I do is pull the carb and "Defeat" the limiter screws. Many of the caps can be pulled off the mixture screws and reinstalled after you get it adjusted. But on some, I take some small diagonal cutters and snip off the nub that keeps the screw from turning.

Other things you should check are:
Spark - should be a nice blue color
Fuel tank vent
Fuel filter - on the gas line in the tank
Fuel screen in the carb
Fuel needle adjustment in the carb

A quick search found this page: http://www.arboristsite.com/community/threads/husky-435-starting-problems.102175/
The last post is a guy that richened his idle mix screw 1/4 turn and it fixed his hot start problem. The tools are available on flea bay, BTW. Good luck!

EDIT After I looked at the IPL the saw probably has a "Stratified charge" engine. They appear to have two throttles but one is just for air. If so the intake "Pipe" is plastic and usually will not re-seal if you remove the carb. I have a 455 Rancher on the bench right now waiting to see what the owner wants to do. Needs the intake-large air leak.

Good tips thanks. Just got the splined tool from felabay for less than $2 including shipping.

 

[DrRoughneck]

Originally Posted By: robshelton
All the new 2 stroke power equipment is set to idle very and I mean dangerously lean. I work on a lot of small engines as a hobby and usually one of the first things I do is pull the carb and "Defeat" the limiter screws. Many of the caps can be pulled off the mixture screws and reinstalled after you get it adjusted. But on some, I take some small diagonal cutters and snip off the nub that keeps the screw from turning.

Other things you should check are:
Spark - should be a nice blue color
Fuel tank vent
Fuel filter - on the gas line in the tank
Fuel screen in the carb
Fuel needle adjustment in the carb

A quick search found this page: http://www.arboristsite.com/community/threads/husky-435-starting-problems.102175/
The last post is a guy that richened his idle mix screw 1/4 turn and it fixed his hot start problem. The tools are available on flea bay, BTW. Good luck!

EDIT After I looked at the IPL the saw probably has a "Stratified charge" engine. They appear to have two throttles but one is just for air. If so the intake "Pipe" is plastic and usually will not re-seal if you remove the carb. I have a 455 Rancher on the bench right now waiting to see what the owner wants to do. Needs the intake-large air leak.


I have not removed the carb but the saw is a refurb so who knows.
I've ordered a new NGK sparkplug to replace the Husky HGT-1 currently in. Figured try the cheap/easy solutions first then see.
If it's not the plug I'll go down your list. Thanks.

 

[DrRoughneck]

Originally Posted By: Chris B.
I had the same issue with a Husqvarna chainsaw and they were never able to fix it under warranty. Got my money back and got a Stihl. I'd advise you to do the same.

I don't use mine for a living but I get your point, it's frustrating. I figured, trying to troubleshoot it is free tuition in 2 stroke unscrewery for me so I'll try the cheap/easy solutions first until I give up.

 

[Kamele0N]

If all above will not work... Then change your CDI unit...

 

[Kawiguy454]

Your symptom actually says it is a bit RICH A cold engine needs more fuel to start and yours cold starts no problem. A hot engine does not need additional enrichment to start and if too rich can wet the spark plug and short the spark. When it is hot do NOT use the choke or priming bulb and if it still wont wont start pull the plug and see if it is wet. The plug should be tan color. If it is darker or blackish it is plenty rich for HS power. I dont know this specific 2-stroke but most have IDLE adjust and HS adjust as was said can be defeated. sounds to me like the IDLE is rich and the HS is set for power like it should be.

 

[Doublehaul]

Originally Posted By: Chris B.
I had the same issue with a Husqvarna chainsaw and they were never able to fix it under warranty. Got my money back and got a Stihl. I'd advise you to do the same.


Id hardly use this as an example of how bad Huskys are. The 435 is a homeowner grade saw and the home owner grade Stihl saws are just as problematic...and there cs is just as bad. Thank 2 stroke emission standards and price point targets.

Professional grade Husqvarna, Stihl, Echo, and Dolmar saws are all very reliable

 

[yeehaw1960]

Simple first is the ticket. Start it, run it for a few minutes, try to start it again. If it won't start, check for spark. Hook ANY different spark plug to the wire nest and check for spark. If no spark, disassemble to expose coil and make sure it doesn't have a bunch of debris around it. If it does, try cleaning it up, but your coil (CDI) is probably fried. Ebay time after that. But first see what a shop would charge for one. Whichever is cheaper...it's the same Chinese stuff! Most of the consumer level machinery has suspect parts...Echo and their dang carbs, Husqvarna and their dang coils and oilers.

 

[DrRoughneck]

Originally Posted By: yeehaw1960
Simple first is the ticket. Start it, run it for a few minutes, try to start it again. If it won't start, check for spark. Hook ANY different spark plug to the wire nest and check for spark. If no spark, disassemble to expose coil and make sure it doesn't have a bunch of debris around it. If it does, try cleaning it up, but your coil (CDI) is probably fried. Ebay time after that. But first see what a shop would charge for one. Whichever is cheaper...it's the same Chinese stuff! Most of the consumer level machinery has suspect parts...Echo and their dang carbs, Husqvarna and their dang coils and oilers.

Makes sense. I'll try the "any spark plug" comparison first to narrow down on plug vs coil. Thanks for the tip.

 

[krismoriah72]

I had a similar problem a few weeks ago with my Husqvarna trimmer.. i thought for sure it was 'worn out'..because once it was warm it would not restart. I got some fresh 93 octane and mixed a fresh batch of fuel and it ran like it always had. I run my OPE at 32:1

 

[DrRoughneck]

Problem solved! Details follow...
I came upon this youtube video on how to clean fouled sparkplugs with a torch:

After the plug cooled down, I gapped it to 0.5mm (it was off at 0.6mm) and started the chainsaw.
After the saw warmed up I shut it down, tried to start it and it did! But it would not hold idle.
Then I adjusted the fuel mixture screw, turned it clockwise 1/4 turn as mentionned above (to enrich I believe) and now it starts right away and holds idle.

Tanks a lot for the hints!

I was pretty convinced that $135 refurb chainsaw off fleabay was a dud. Well maybe it was, but I managed to fix it for free! We'll see how long it lasts...

 

[lars11]

A husky can maybe always be rejuvenated with fairly simple work unless the main crank or cyl/housing is wasted.

You found one of the common probs, often ignition will be the culprit with hard starting warm engines, sometimes the condensator or the cdi unit will be bad. There are bad plugs too, but not soo often in my opinion. That gap difference should not cause hard starts, i think.

I had another warm engine problem in my hva 140r from like '78-80; The air cleaner screen was almost completely plugged (but looked ok), it started fine but was a bear to run or start when hot. Cleaned it and re-set the carb and works like new again. It had some "invisible" hard stuff in the mesh that really needed dishwashing and compressed air. So don't just look at the mesh, assume it is plugged.