HD-12 will not hold a nice idle tune on 372..

[Adamski]

This HD-12 on my 372 is giving me heart ache. It will not hold it's idle. One minute it dies from too low a mix the next time after a cut it makes the chain creep. I have tested every seal, gasket and case gasket. Their are no leaks. Any one else have an issue with these carbs. You only have to put the screwdriver ONTO the low adjust and it changes its speed. Idle does not change if I flip the saw etc. Chime the posts about an airleak.. I have tested everything. I am now blaming the carb..

 

[mdavlee]

I had a few like that. Never did get them sorted out. I just get another til one worked

 

[Adamski]

I had a few like that. Never did get them sorted out. I just get another til one worked

Am or genuine oem? This oem Walbri sucks ass for sure.

 

[Stihlbro]

Check your throttleshaft for wear. Especially on the side opposite of the cable hook up. I've got several that are sloppy. Sometimes you can loosen the throttle blade screw, shift the throttle shaft over and it will snug up.

 

[Czed]

I've had to replace several oem over the years even after ultrasonic or carb soak and with new kits they were done.
Sometimes you can't save them.

 

[Gary Courtney]

check butterfly to make sure it is aligned properly
check metering lever

 

[mdavlee]

Am or genuine oem? This oem Walbri sucks ass for sure.

Oem

 

[Cut4fun]

I got oem one that went bad somehow doing same crap on a 372. After I chased symptoms and ended up at carb. Tried carb swap and all was good.
Never figured out what went wrong with carb. Went to the parts bins.

 

[Adamski]

check butterfly to make sure it is aligned properly
check metering lever

Check your throttleshaft for wear. Especially on the side opposite of the cable hook up. I've got several that are sloppy. Sometimes you can loosen the throttle blade screw, shift the throttle shaft over and it will snug up.

I have Set the metering spring. If the butterfly and shaft are OK I'll order a new one. Bloody thing

 

[Mattyo]

I've had some that have 2 idles....I've never figured out the issue either. ...toss.

 

[Ktoom]

Im actually going through a similar problem with a new walbro wj118 on my 2188. The darn carb is brand new, but the saw wont idle smooth at times. Coming out of a cut, the idle drops for a bit then comes back up. Yet the saw runs awesome in the cut. I played with the low side and idle, till i found a happy medium. I vac/press tested the saw numerous times and found no air leaks.

This little issue has prevented me from posting the old girl for sale.... needless to say, I will be posting it soon.

 

[Definitive Dave]

Oem wj118 or aftermarket?
Check that the linkage is completely free, occasionally they can hang slightly and don't return 100%

 

[mdavlee]

Im actually going through a similar problem with a new walbro wj118 on my 2188. The darn carb is brand new, but the saw wont idle smooth at times. Coming out of a cut, the idle drops for a bit then comes back up. Yet the saw runs awesome in the cut. I played with the low side and idle, till i found a happy medium. I vac/press tested the saw numerous times and found no air leaks.

This little issue has prevented me from posting the old girl for sale.... needless to say, I will be posting it soon.

It could be a little trash in the throttle cable if it's got a good bit of use or rubbed through and hanging up.

 

[jockeydeuce]

I have a bucket of HD12's with similar idle circuit issues. ....I'm sure some of them are bad main nozzle check valves. So far I've just been carb swapping until I get rid of the issues.....They are frustrating.

 

[rattler]

If you can find a hd6 to try.

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[Adamski]

So has anybody used a Stens OEM genuine carb replacing the walbro HD-6?

In the UK I can't find a local Walbro HD12 or 6. Need to get one shipped from you guys over the pond..

 

[Adamski]

So I tore down the oem HD-12 carb yesterday, pulled all the choke and throttle links, flaps, shafts etc, cleaned and reassembled.

After a cowboy pressure test with blue tack around the choke and throttle shaft ends, and a hand over the bore and blowing through the other end, I found that there was an air leak through the tiny hole that the return spring of the choke shaft sits in on the outside of the casting. Pretty perplexed as how or why air is coming out but a little JK weld and a redrill this morning and the carb is back to fully functioning... o how I forgot how much I like this saw..

 

[David Young]

So I tore down the oem HD-12 carb yesterday, pulled all the choke and throttle links, flaps, shafts etc, cleaned and reassembled.

After a cowboy pressure test with blue tack around the choke and throttle shaft ends, and a hand over the bore and blowing through the other end, I found that there was an air leak through the tiny hole that the return spring of the choke shaft sits in on the outside of the casting. Pretty perplexed as how or why air is coming out but a little JK weld and a redrill this morning and the carb is back to fully functioning... o how I forgot how much I like this saw..

? I need a picture but really interested in what you are saying

 

[Adamski]

So I mean the tiny little hole to the right of the choke shaft hole. It leaks a lot of air. Or draws in alot of air. What ever was happening is all now OK!!

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