Repair old Husqvarna 61 advise

[honda4life]

Hello,

I got the old Husqvarna 61 (1984?) from my grandfather and used this saw in the past as a backup second saw because it did run quite bad (age?).
Running idle was somewhat possible after tuning the carb, when using the saw the chain runs too slow with my impression way too rich.

Until my saw broke and I run a full tank of gas on the 61, at the end the beast was awake because I think air got into the fuel line and the mixture was a bit leaner.

Okay, the hole in the carb from the choke valve axis is a bit worn out from the vibrations over te years, so this might give some minor air leak here.
Should I replace the carb, or should I try to replace the membranes first?

Membrane kits from AliExpress any good?
For example: https://www.aliexpress.com/item/4000366314914.html

Any manuals available how to replace the metal disks etc?
Or should I just do the membranes and the needle valve?

(Non native English, European)

Thanks

 

[2StrokeFondler]

I have okay experience with Chinese carb kits. If they fit, and nothing's obviously broken, they usually work just fine. Had a thing with a kit for an 015 once, where the plunger on the metering diaphragm was longer than the original, so I had to bend the needle arm a bit. Didn't see it at first, so the saw was running pig rich till I found the error. Glad I always safe the old parts for comparison.

I usually don't change the plugs (metal disks) if I don't see a specific reason to do so.

Looks like an earlier 61, could/should have a two piece ignition. Good saw.

Cannot help you on the choke axis. No idea how to test if that's an air leak. Maybe some of the pros here have an idea.

 

[honda4life]

Okay, is it a 61 or a 61 Rancher, can't find out for sure.
Some workshop manuals available for this old saw?

 

[2StrokeFondler]

Okay, is it a 61 or a 61 Rancher, can't find out for sure.
Some workshop manuals available for this old saw?

Don't know if 61 or Rancher, but I'm sure somebody here will chime in soon.
I have a German workshop manual, if you like.
Otherwise: https://www.arboristsite.com/threads/husqvarna-272xp-owners-manual-and-service-manual.359639/

 

[J D]

61 is a great platform well worth putting some time into.
Sounds like the carb was fouled up & running fresh mix has helped dissolve some of the varnishing etc. Definitely worth putting a kit in the carb.
I wouldn't worry too much about play in the choke shaft unless it's really excessive. It won't contribute to lean running as it is "before" the carb. A smear of grease around it may be beneficial

 

[J D]

Here is a broad Husky service manual

 

[honda4life]

It is a Walbro WS17B.
You can see the clearance.
Piston looks great trough the intake port, compression feels very strong.

The manual is for the newer saws, but probably some useful information can be found.

 

[honda4life]

The Low and High screw are completely in, the idle screw is maximum. Gives me some revs.
I still think it's running too rich?

 

[2StrokeFondler]

The Low and High screw are completely in, the idle screw is maximum. Gives me some revs.
I still think it's running too rich?

Wait, H and L are turned clockwise as far as they go, and the saw still starts, idles and revs? Somethings wrong with the carb, for sure.

 

[JoeMay]

Last year I put a Meteor P&C on a Husky 61 Practica, which is the very early version of the 61 farm/ranch saw. Also rebuilt the Tillotson carb. Then I gave the saw to a brother as a house warming gift; pun intended, he has now got a fireplace. I wouldn’t focus the choke shaft’s play. Highly unlikely it is a key source of an air leak. As long as it locks properly opened and closed it is fine. I’d instead focus first on the entire Walboro carb. Completely disassemble it, thoroughly clean it and carefully install the correct Walboro rebuild kit. If problems persist, move on to fuel line and filter and tank venting.

 

[ballisticdoughnut]

If your intentions are to continue using the saw into the foreseeable future, your gonna want to do a few things. New carb kit, fuel hose, and fuel filter at a minimum. Get genuine parts if you can. If after that you can tune the carb and get it to run correctly your probably ok although if it were my saw, I’d replace the crank seals and o-rings as well.

 

[irhunter]

+1 for full name-brand Walbro carb kit and new Husky fuel line/filter.

As far as the carb rebuild, I go by what Walbro suggests:

 

[J D]

All good advice above...
Be carefully not to "tighten" the mixture screws or you will damage the seating surfaces. If you have them all the way in & the saw will still run to any degree it is likely the metering valve isn't sealing properly. You can pressure test the carb to verify this by putting about 10psi on the fuel inlet... it should hold that pressure indefinitely

 

[Old-Feller]

Get it running again and spray brake cleaner behind the clutch, If it dies, There is your air leak, The crank seal on the clutch side is bad if it dies after spraying it with a hefty dose of brake cleaner. Not saying this is your problem, But it's an easy way to eliminate that as being the problem. When you can't adjust the carb enough to get things running good, It's possible you have an air leak such as a crank seal.

 

[J D]

Get it running again and spray brake cleaner behind the clutch, If it dies, There is your air leak, The crank seal on the clutch side is bad if it dies after sparaying it with a hefty dose of brake cleaner. Not saying this is your problem, But it's an easy way to eliminate that as being the problem. When you can't adjust the carb enough to get things running good, It's possible you have an air leak such as a crank seal.

While I wouldn't rule out the possibility of an air leak there must be a carb/fueling issue if it will run on both jets wound all the way in (unless the wrong springs are fitted on the screws & that is limiting their travel)

 

[honda4life]

Checked the complete carb again with pressure testing.
The good thing is you can push te metering valve open on this carb.
High and Low needle opening an closing is ok, no air leaks, all jets clear.

Created some equipment to pressure testing the complete saw.
I was a bit suprised about the amount of blowby on the piston towards the sparkplug, but considering the good compression when pulling the starter I think this is normal.

I'm more concerned I think to hear some air leaking from behind te flywheel... I guess that will be the cause.
It doesn't sound that much, but probably enough to mess things up.
Need to check tomorrow.

 

[irhunter]

Yup...if you can hear hissing...it's too much.

The shop manual has specs on how much pressure and vac the case should hold (and, for how long).

 

[Cantdog]

Yup...if you can hear hissing...it's too much.

The shop manual has specs on how much pressure and vac the case should hold (and, for how long).

If you hear it, it's for sure leaking way to much. Behind the flywheel is a seal carrier that is held in with three bolts. Remove it and replace the seal....very easy with it out of the saw case. Order the correct o-ring that seals the carrier to the case from Husky......very specific size. If it were me I'd double the order and replace the oring and seal on the clutch side too. Cheap insurance.....do 'em all......

 

[Puffie40]

One other place to check for air leaks is the four screws holding the cyilinder down. I have encountered those had worked themselves loose in the past.

 

[JoeMay]

Does one of the crankshaft’s tapered ends on that saw have a raised step on it? That step can easily invert the lip of the new seal as it’s being installed. You won’t know if this has happened. If it did you’re back to square 1. Use an aluminum drink can to cut yourself a little sleeve to guide and ease that seal over that step.