026 help...take two!

[Woody33]

It's been a while since I posted this problem about my 026 and I still haven't been able to solve it...here is a link to my first post:

http://www.arboristsite.com/community/threads/help-ported-026-problems.245613/

This project has been on the back burner for a while now and I have just recently had a chance to revisit it. As an update, we figured there was an air leak somewhere so I've replaced the fuel line, impulse hose, and intake. As well, I've resealed the cylinder base with motoseal. Nothing has changed the way the saw runs. It will still idle nicely, and bog out when I apply the throttle. If I slowly blip the throttle, I can get the saw to WOT before it bogs down. I'm about ready to give up. Basically, what I'm thinking is that I opened the exhaust a little too wide and now the rings aren't sealing properly and I'm loosing compression. After inspecting the cylinder, I did go a hair closer that 2mm on one side of the exhaust. Do these symptoms sound like this could be the case? I'm ready to buy a new cylinder and try all over again...any advice?

 

[mdavlee]

Going that close to the edge of the skirt isn't causing that problem. You've got a carb or fuel delivery problem. Where are the L screw and H screw from seated?

 

[Ozhoo]

If you're so certain of a troublesome air leak, strip it down and pressure test it in a 5 gallon buck of water. But I agree with mdavlee, it's more likely to be a carb problem.

 

[z71mike]

Yup. Even if you opened the exhaust too wide, it would still run fine, just probably be a little low on power.

 

[Woody33]

Wt-22 carb. Stock settings for L and H screws (1 turn out). I've put a new carb kit in as well. Maybe I buggered something myself (most likely) but I double checked the diaphragm/gasket arrangement and they are correct. Would I have to open the metering lever to allow more fuel in or just adjust the H and L screws because I have tried almost every arrangement of H and L and nothing really changes in the saws performance. I'll see if I can get a video up of it running but it's cold and windy as all hell up here today (northern Manitoba, Canada)

 

[fearofpavement]

I agree with the others that you have a fuel issue. Start by opening up the L another 1/4 turn and see if that makes a difference.
If you can find another 026 and can exchange some parts to see if you can move the problem, that may be one of the best ways to troubleshoot your issues. I would try a new/different carb. If it turns out to be that (likely) then you can pursue the defective one to see if you can get it resolved. A Chinese replacement isn't that expensive and may solve the problem. Do you know anyone that has an 026?

 

[Woody33]

Don't know anyone with an 026.. I have an ms250 at my disposal but not certain the parts are the same. I took a video but I can't upload it because it's an mp4 file (whatever that means) and I am severely illiterate when it comes to technology (and apparently chainsaws as well)... I feel as though a Chinese replacement carb might cause more headaches down the road...

 

[Ozhoo]

Did you put in a full carb kit or just a diaphragm kit? Did you mess with the welch plug? Adjustment screws are in good shape? So many questions, so little time.

Also, consider putting an add in the trading post before going aftermarket.

 

[Woody33]

Full kit, diaphragms, needles, Welch plug, metering lever etc....do you think I need to increase the flow of fuel by adjusting the metering lever ? I wish I could play this video...i'm going to try and convert it. Idles great but bogs with throttle as if running lean and then starves for fuel but no amount of adjusting the l or h screw fixes anything?

 

[Ozhoo]

Post your video on youtube. A low metering lever will cause your problem. It should be level with the carb body. Take a gander at this troubleshooting chart to see if anything sticks out to you.

 

[Ozhoo]

If you don't already have it, here's the WT service manual. The Walbro Service Manual also makes for a good read and covers operation/troubleshooting.

 

[asand1]

Did you replace the crank seals?

 

[angelo c]

What sort of case pressure testing have you done? 26's are known for weak seals but im betting on metering level.
Post up a request to borrow a carby in your area. I bet you will find someone who will help or mail you one.

 

[Milkman31]

You could take a look at two eazy things that may help. First make sure that the gold looking pin is in the filter and holding the choke lever in place.yeah I know this filter is no good. Second make sure the air passages in side the Venturi are clean.I use torch tip cleaners for this. And yes this carb is from a husqvarna but same idea on the 026 carb. Hope this is a help.

 

[sld961]

I'll throw another vote on metering lever. Definitely check that.

 

[Woody33]

Thanks so much everyone for the responses.. its tough to diagnose something when I'm not 100% certain what's causing it.. i'm going to play with the metering lever but when I replaced it with the one in the rebuild kit, I leveled it with the carb body. The gold pin is in but I'll check the air passage. I'll start a youtube acct and post the video. Really nothing exciting, just might help give an idea of what it's doing.
The reason I am questioning the jug is because the saw was in great condition when I bought it and was a strong runner before I mucked with it and started grinding away (although once I get it running it should be a screamer!). But after reassurances about the jug, I guess the next thing to suspect is the fuel delivery...thanks again guys, I love these little saws and can't wait to tear into.some wood!

 

[Woody33]

Sorry, crank seals were not replaced.
I did a "shoddy" homemade pressure test with my compressor at 7psi and it actually showed no loss of pressure over about 1 min but this was obviously not the best way to do it but it's all I have at my disposal..im up north in a town of ~500 people so not much in the way of help by dealers etc.

 

[Woody33]

Couple pics of metering lever it is level with the carb body as seen in picture, should I lift it to allow more fuel?

 

[Ozhoo]

Well there's your problem. See below of what "level with the carb body" means. A straight edge across the carb works fine.

 

[Woody33]

I don't understand? Isn't that where it is set, my flat edge just touches the lever without opening the needle?