Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Husqvarna => Topic started by: Eliott on January 13, 2014, 05:18:40 pm


Title: 281 Husqvarna, carb problems?
Post by: Eliott on January 13, 2014, 05:18:40 pm

Hey folks,

First post.

 '97   281 Husq'.

Put in a new carb kit, new fuel line, fuel tank grommet and new hose.

Was working before this upgrade, now it don't.

Can start it, have to hold the choke plate open just a crack to allow it to idle, as soon as the choke lever is pulled back, plate open... she dies.

Have stripped the carb twice, blew it out, soaked in carb cleaner, assembled with care.

As previously mentioned. With a worn needle, soggy, old diaphragm, gas leaking all over place from a rotten fuel tank grommet, **** fuel hose, was able to start and run... cut with it.
Treat her nice add some new stuff and poof! , no go.

The tilliston carb H, where is the metering lever supposed to sit. Flush to the carb floor or flush to the lip where the gasket lays?

Have had it both ways today. A little better with the lever flush to the carb floor. See pics please.

Now I am thinking air leak, seals? just dunno at this point. Why would it run, and then not after fixing all with in a couple of weeks?

Compression good, piston not scuffed up, she digs pretty good when cutting.

Need the old beast for chainsaw carving and have a 7 foot on the stump old wolf pine to fell, right soon.

Tanks for reading guys, have a good one.

Eliott
Title: Re: 281 Husqvarna, carb problems?
Post by: Eliott on January 13, 2014, 05:21:27 pm
Pics too large.
Not sure how to get down to 400 kb's or lower. If successful, will post them.
Title: Re: 281 Husqvarna, carb problems?
Post by: Eliott on January 13, 2014, 05:27:23 pm
pic
Title: Re: 281 Husqvarna, carb problems?
Post by: jmester on January 13, 2014, 07:50:03 pm
The metering lever should be level with the floor or recessed area where the needle,lever and spring are. Make sure your gasket is to the carb and metering diaphragm to the cover, on the pump side the pump diaphragm to the carb and gasket to the cover.  Hope this helps
Title: Re: 281 Husqvarna, carb problems?
Post by: jmester on January 13, 2014, 07:53:55 pm
Your lever height in your pics look to be right. On the metering diaphragm the side with the disc goes towards the lever.
Title: Re: 281 Husqvarna, carb problems?
Post by: Eliott on January 13, 2014, 07:59:05 pm
Thanks for that input. The diaphragm nib fits into the meter lever notch doesn't it ?
Title: Re: 281 Husqvarna, carb problems?
Post by: jmester on January 13, 2014, 08:21:50 pm
Yes on some they do. Did you keep your old one to match it up. Also not that familiar with that model husky, how does the gasket or seal look where the carb mounts. Could be an air leak there. Also just go back where you where working and make sure everything looks right. It is easy to forget something no matter how many times you have done it.
Title: Re: 281 Husqvarna, carb problems?
Post by: jmester on January 13, 2014, 08:29:38 pm
Also check you basic setting of the high and low speed screws a go place to start would be 1 to 1 and 1/4 turns out from a light seat.
Title: Re: 281 Husqvarna, carb problems?
Post by: Eliott on January 14, 2014, 07:02:34 am
jmester, thanks again. the H-L has been set many times,many different ways.

As I trouble shoot the air filter is off, top cover off, and screw driver handy to adjust as it tries to run.  Even if they were off a bit she would still run way better than it does now,

Pretty sure the diaphragm slips into the notch.

I am knocking off the clutch today.

You have a clear way with description,  :), appreciate you coming in on this post.
Title: Re: 281 Husqvarna, carb problems?
Post by: Eliott on January 14, 2014, 09:59:16 am
Killians', hi, thanks for the input.

New needle. Making sure it is free'd up and lever tangs are properly fitting into the groove at the top of needle.

Took carb apart once again last night, did a complete strip down, immersed in carb cleaner. There was some small rust'dirt particles at the bottom of the glass receptacle... surprised me as it has been cleaned and blown out twice already.

Will see how it runs shortly. Starting to source out seals for the 281, may have to go that route, need to do a test to see if seal is seeping... the easiest way possible. :-\

Title: Re: 281 Husqvarna, carb problems?
Post by: KilliansRedLeo on January 14, 2014, 10:12:50 am
I blew up the picture, I was wrong your have it in place correctly!
Title: Re: 281 Husqvarna, carb problems?
Post by: Eliott on January 14, 2014, 11:38:02 am
Yes the blow up helps. I do it quick, press ctrl and + at same time and click a few times, will bring them in, use the minus sign with ctrl to zoom out.

more carb pics this morning. looks pretty clean, 'eh. ;)
Title: Re: 281 Husqvarna, carb problems?
Post by: sharkey on January 14, 2014, 04:00:24 pm
Go over to Tillotsons website and look up your carb.  Study the pics.  Make sure you put the diaphragms and gaskets in the correct order.  On the metering side the gasket goes against the carb body with the diaphragm over it followed by the cover.  On the pump side its the opposite with the diaphragm against the carb body and the gasket over it followed by the cover. 

Did you check your fuel line for cracks?  Where the line goes through the tank is a place to check. 

Open each jet 1 and 1/2 turns from lightly seated as a starting point. 

Title: Re: 281 Husqvarna, carb problems?
Post by: Eliott on January 14, 2014, 06:21:44 pm
All gaskets in correct order. Fuel line is new, as is the tank grommet. Jets set correctly as saw was started, tried and run at various times. .

Worked better today after reassembly, but I'm afraid there is air leaks. So into the seals now ... .
Title: Re: 281 Husqvarna, carb problems?
Post by: Eliott on January 14, 2014, 06:49:08 pm
For those good folk that would like to hear and see the old beast chatter and suck, go here,
http://youtu.be/J_U5oxC18d8  .

You can see the choke plate being manipulated, kept slightly open in order to keep it running... eventually it opens up too much and kills the saw. 
Title: Re: 281 Husqvarna, carb problems?
Post by: KilliansRedLeo on January 14, 2014, 06:58:42 pm
OK, new seals it is, the flywheel side is HVA part number 503 26 02-05, the clutch side 'O' ring is HVA part number 740 42 24-00 and the clutch side seal is HVA part number 503 26 02-05 total price around $26 plus ship. You should replace the 'O' ring as it keeps crap off the seal!
Title: Re: 281 Husqvarna, carb problems?
Post by: dutchsawdoctor on January 14, 2014, 07:38:10 pm
Strange to need new seals as it whas running better befor the carb. rebuilt ??? Sounds more like a bloked off puls line do( i could be wrong ) ::)
Title: Re: 281 Husqvarna, carb problems?
Post by: KilliansRedLeo on January 14, 2014, 07:52:00 pm
Good thought Saul! The 181 did use an internal pulse through the manifold. Could be a misplaced or mis aligned gasket. Or the face of the manifold could be clogged! Looks like he should take it apart again! May even be that the passage through the cylinder is partially blocked. We all know how much goo gets clustered around the intake tract on an older saw! However that would require removing the cylinder to clean out the cylinder port.
Title: Re: 281 Husqvarna, carb problems?
Post by: Eccentric on January 14, 2014, 08:32:33 pm
That o-ring on the oil pump housing is critical because the seal is in the pump housing, and the pump is exposed to crankcase pressure/vacuum.  Should replace that o-ring any time you remove the oil pump.  Crank seals on both sides are the same on the 281 and 288 (and later 181SE's).  Early 181SE's had a different flywheel side seal. 

I also am thinking it's an impulse signal issue here, since it ran fine before all this.  Could be some crap in the impulse channel, or maybe a bum (or misaligned) gasket (on one or both sides of the manifold).  The manifold could also have developed a crack that was 'opened' enough to leak during the dissassembly/reassembly process. 

Also, that carb does have a metering lever with forks on both ends..................and therefore you must slip that fork into the groove on the 'tit' on the metal plate on the metering diaphragm for things to work right.  When that isn't done, the saw usually stumbles and floods however.  The diapragm also goes onto the carb body after the gasket on the metering side........................while the diaphragm goes on before the gasket on the pump side.
Title: Re: 281 Husqvarna, carb problems?
Post by: KilliansRedLeo on January 14, 2014, 08:56:48 pm
+ 1 on that Eccentric!
Title: Re: 281 Husqvarna, carb problems?
Post by: Eliott on January 15, 2014, 02:10:06 am
Thank-you gentlemen 'all. That is why I am here to get into the real nitty gritties.

Saws have been a large part of life. Logger, feller, forestry/chainsaw/clearing saw instructor, silviculturist/chainsaw/power carver.
First pulled the saw'stinger in 1969 when a 'wee power'saw kid.

Owned 60 to 70 saws over the course of a long career in the wild, deep woods. Operated, loved and cursed most major brands, European, Asian, American and even Canadian... 'eh  ;)
Learned to fix most... a lot of them on the fly, in the bush on a log, pulp pile or a snow bank.

This 281 is a trade, swapped out, in exchange for a little Stihl I fixed up, we were both happy.

Came to the point with the gas leaking out through that bad tank grommet seal, and as the fuel hose deteriorated and ripped, she finally quit. Used sporadically over three years, so 'hey it was expected... needed rear mounts anyway, so decided to upgrade and throw in what I could.

Yep, the impulse was considered, still is, and with renewed vigour as the feedback comes in. The original gasket to the head was ripped, so at this point with each tear down of the carb, have made, three gaskets from good gasket paper, hoping the last one pictured here is sealing properly, quite sure it is. Making sure the impulse hole is drilled out too, aligned with hole in head.

Oh yeah, the new gasket to the insulator has a hole in it, does it align to the factory hole? picture included.

Pried off the oiler/seal plate and as you can see pretty much plugged up.

The O-ring, not pictured does look ragged, not sure about the seal. Putting a picture up.

The expert info from you guys is a help indeed. Some good investigative tips... 'fer sure.



Title: Re: 281 Husqvarna, carb problems?
Post by: Eliott on January 15, 2014, 07:48:25 am
seal shots to follow, one side only at this point, will do some impulse C.S.I. before going on. ...
Title: Re: 281 Husqvarna, carb problems?
Post by: Eliott on January 15, 2014, 06:02:04 pm
 :o Well another part day tinkering, deciphering, retreating, returning, rebuilding.

After cleaning up the crud, making yet another gasket, trying a few new starts and tunings, finally... finally there appears to be a breakthrough.

Took a break... .
http://youtu.be/pzDUacUnZhY

After getting the old gal together and reasonably sure there was a real chance of maintaining a running chain, took it out to the woods. Demo next post.
Title: Re: 281 Husqvarna, carb problems?
Post by: Eliott on January 15, 2014, 06:47:40 pm
Appreciate the help, the guys that came on here, shared their knowledge. Thank-you, sirs.

The chain wasn't sharpened but was wanting to get over to the wood lot and try the saw in a small log, needs a bit of a tweak on the high speed, she is pulling through pretty good... heck of a lot better than yesterday!

http://youtu.be/vYG5zbHFtQk

We got a lot of wood to carve up! Ancient wolf tree making way for blueberry land the owner tells me.
Title: Re: 281 Husqvarna, carb problems?
Post by: KilliansRedLeo on January 15, 2014, 07:00:44 pm
Sounds like a Husqvarna! Nice work! However, cutting one-handed while making a video is NOT a safe practice, JMO!
Title: Re: 281 Husqvarna, carb problems?
Post by: Eliott on January 15, 2014, 07:10:49 pm
yep, she does... was waiting for the 'one handed to come in... does it help if I was looking away?

It won't be up long, lest I get 'tubed sued or sumpthin' ... and to think I was a chainsaw safety instructor 'eh.
Title: Re: 281 Husqvarna, carb problems?
Post by: KilliansRedLeo on January 15, 2014, 07:41:31 pm
Like the shoemaker's kids. ::)
Title: Re: 281 Husqvarna, carb problems?
Post by: dutchsawdoctor on March 23, 2014, 04:52:19 am
Appreciate the help, the guys that came on here, shared their knowledge. Thank-you, sirs.

The chain wasn't sharpened but was wanting to get over to the wood lot and try the saw in a small log, needs a bit of a tweak on the high speed, she is pulling through pretty good... heck of a lot better than yesterday!

http://youtu.be/vYG5zbHFtQk

We got a lot of wood to carve up! Ancient wolf tree making way for blueberry land the owner tells me.

Sounds like healty HVA, good job done