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Husky 61 hard to start after warmed up and partly cooled

Started by Canadiana, August 27, 2016, 01:31:39 AM

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Canadiana

My husky 61 starts well. Idles almost ok. After running til up to temperature, then shutting it down; if it is left to cool off for a few minutes it is then harder  to start than when cold started. I've only been successful in getting it running again with several start n stalls and using full throttle with various stages of choke. After about 1min of run time the saw seems to return to its normal state. I'm not sure where my repair or trouble shooting  should begin. Thanks for any input
The saw is more fun than the purpose of the wood... the forest is trembling 🌳

millwright

My 61 tends to vapor lock , if I let it sit it will start after a bit and will run fine

John Mc

It does sound as though it may be vapor lock - basically some of the fuel boils and turns into a vapor in a place in the fuel system where it's still supposed to be liquid. Usually, it doesn't lock when the saw is running, since you are constantly pumping fresh fuel through the system. Once it shuts down, and the fuel stops flowing, the parts that are near hot spots on the saw can bake in the residual heat and turn to vapor.

On SOME saws you can minimize this by not shutting down immediately after some hard cutting: let it idle for a bit so the saw can cool down a bit while the fuel is still flowing.

Another thing that can help is to make adjustments or modifications so the saw runs cooler (make sure all of your cooling fins are clean, maybe run a tad richer, swap out a catalytic muffler for a non-cat one, or possibly open up a restrictive muffler so it can breathe better). I had this problem on my Jonsered 2152 (sister saw to a Husky 353). Switching from a catalytic to a non-cat muffler and retuning solved the problem.
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

HolmenTree

Check to make sure the cold weather window in the top cover partition is not open allowing cylinder heat back to the carburetor.

These older 61 Huskies had cylinder bolts attaching the carburetor allowing cylinder heat to transfer to the carburetor heating it up.
Stihl's ever since that era had a rubber thermal insulating intake manifold preventing vapor locking. But in the winter these Stihl's iced up easily.

As the old saying goes " Huskies great winter saws. 
Stihls great summer saws."

Making a living with a saw since age 16.

weimedog

Quote from: John Mc on August 27, 2016, 06:56:51 PM
It does sound as though it may be vapor lock - basically some of the fuel boils and turns into a vapor in a place in the fuel system where it's still supposed to be liquid. Usually, it doesn't lock when the saw is running, since you are constantly pumping fresh fuel through the system. Once it shuts down, and the fuel stops flowing, the parts that are near hot spots on the saw can bake in the residual heat and turn to vapor.

On SOME saws you can minimize this by not shutting down immediately after some hard cutting: let it idle for a bit so the saw can cool down a bit while the fuel is still flowing.


Hope those with the new strato saws like the 562's are also reading this excellent explanation AND simple solution.. intelligent muffler mods can also help but who wants to hack a NEW saw??? And in some cases intelligent top cover mods can help. BUT back to those older Husky's, John Mc & Holman Tree pretty much summed up many years of collective experience in two posts...
Husqvarna 365sp/372xpw Blend, Jonsered 2171 51.4mm XPW build,562xp HTSS, 560 HTSS, 272XP, 61/272XP, 555, 257, 242, 238, Homelite S-XL 925, XP-1020A, Super XL (Dad's saw); Jonsered 2094, Three 920's, CS-2172, Solo 603; 3 Huztl MS660's (2 54mm and 1 56mm)

John Mc

I agree, Weimedog: who wants to go hack a brand new saw? In that case, you are limited to cleaning the cooling fins, adjusting the mixture (if it's not an auto-tune saw), and letting it idle a bit. I'm guessing Canadiana's Husky 61 is not still under warranty :D

I'm sure there are other things that might contribute (weak spar plug or coil, for example) but I'm not much of a chainsaw mechanic.

If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

tranabo_bjoern

I am a bit late on this post. On my old 61 I change in cold days to a mesh filter. The standard filter does not run well in cold weather even the saw is in winter mode (hole to the filter is open). This helped a lot.

I do the same with my 395.
Just do it!

Husky 395xp 20 inch bar
Husky 460xp x-torq Rancher 24 and 20 inch bar
Husky 61 18 inch bar
Jonsered 2234 14 inch bar
McCulloch cs 380 18 inch bar

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