Chainsaw Repair
Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Jonsered => Topic started by: JonF on May 27, 2014, 05:00:42 pm
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I just picked up an old 2040 turbo to chop some logs up for winter etc.
I have replaced the carb gaskets and cleaned it all up. It's a wabco WT289 so pretty common I think.
The saw has a good spark and compression.
The carb is picking up fuel as you can see it running up the clear lines. However it seems to be over fuelling and flooding. If I clamp the fuel line after a few pulls, the saw will run up fine for a few seconds. When I unclamp the fuel feed line, the saw dies.
I have checked the inlet needle and it seems to seat correctly and is held in by the metering lever.
Anyone experienced this before? I am not sure else to check.
Any help from the experts out there is very welcome.
Jon
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If you have the metering valve diaphragm against the body of the carburetor with the gasket between the diaphragm and the steel cover it will hold your inlet needle open
Whatever, the needle is being held open
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You also need to check you metering lever height. It should be level with the recess for the lever.
http://www.walbro.com/servicemanuals.aspx. Look at the service manual for a wt carb.
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Is the saw "filling" itself with fuel while it sits? Also a tell as to if the metering valve is closing. They make metering lever tools for both zama and walbro. 2 of the best tools for 2 stroke repair that I have purchased.
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I use a pressure tester on the fuel inlet to see if the carb holds about 7 lbs pressure. I release the metering valve to see if it lets the pressure go and then re-seats itself?
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Thank you for the advice. I will try the suggestions and get back to you.
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So I have checked the gaskets are correct. The metering lever is set at about 1mm below the recess. Still seems to over fuel.
If I give the saw a couple of pulls with the fuel line open then close it, the saw starts and runs ok for 5secs. As soon as I unclamp the fuel line, it dies.
Should I try changing the metering needle too? Not much else is there?
The carb to cylinder gasket is not great but I guess the pulse must be ok as it is over fuelling it.
The other thing I have noticed is the saw tends to leak some fuel from the crank case screws in the bottom of the housing. Not much but enough to leave a mark.
Thanks for the help.
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If the needle has a worn ring around the tip it will never seal reliably.
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Have you played around with you adjustment screws to see if that helps.
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I had a stihl 029 in that would flood itself no matter what I did to carb. Finally gave up on that carb and put the same new rebuild kit in another carb and all was fine then. My WAG = I think the seat is causing the flooding, needle seat has ware or something.
You have tried a complete carb repair kit with new needle installed right? Not just a diaphragm kit.
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I tried a complete kit over the weekend (gaskets, needle and screen) and it is still flooding. Very frustrating.
I followed setup procedure for walbro wt carb and have the needles at 1.25 turns out. It floods so fast from opening the fuel line that I think needle adjustment seems unlikely. Will try though.
The carb to cylinder gasket is not looking great but I guess it must seal as the pulse is still good - I am getting too much fuel rather than not enough.
Also, when it does run it seems to leak a little fluid from the crank seal, chain side not generator side. It's not chain oil as I have blocked the port. If I am loosing crank case pressure, will this effect anything?
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I had a stihl 029 in that would flood itself no matter what I did to carb. Finally gave up on that carb and put the same new rebuild kit in another carb and all was fine then. My WAG = I think the seat is causing the flooding, needle seat has ware or something.
Try another carb.
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Question I tried looking up a jonsered 2040T IPL as you have listed. Nothing.
Is this saw a jonsered 2040 rear handle or is it a T = top handle?
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If so new only $26. http://www.jackssmallengines.com/Parts-Lookup/530035330/2153436/PL
530035330 Supercedes to 545013503 REP BY 530069629
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Saw is a 2040 Turbo, hence T.
That carb looks correct. I have certainly spent $30 of time on it!
I will try that. Thanks.
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Thanks, I was thinking there was a saw how I couldnt find again. Fixed heading.
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Looking at that jacks link it says fits these too. Might look for a donor off these saws. Poulan 2200, 2750, 2775, 2900, 3050, 2500, PP4620AVX, PP295 Chainsaws
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if the welch plugs have been messed with, or there is any corrosion under them that's pushing them out, it will cause flooding issues.
this is the same saw as the Husqvarna 40-45-49. lots of parts everywhere for these.
you do have the spring under the lever don't you?
are you sure it's the correct needle? there needs to be fuel pressure to 'fill' the metering side of the carb, and it needs to be quite a bit to do so. so if the diaphragm is in the right place, and all corresponding parts are ok, there shouldn't be any fuel getting in unless that spring is either missing or somebody has messed it up. not much to these carbs to cause problems. they're not rocket science. so long as all the parts are in place, and properly, there shouldn't be any issues like this. this is one of the most reliable carbs out there.
regardless of the flooding. if a crank seal is leaking fuel out no matter how full the crank case is, that seal needs to be replaced. if it's leaking through the mounting bolts, the bottom end needs to be re-sealed which means a total tear down. you have more work than just the carb. and running that saw with said issues will burn it up quick. maybe it's time you visit the local small engine shop for an opinion from somebody who can have the saw in front of them for a proper inspection. before you waste more time and money.
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regardless of the flooding. if a crank seal is leaking fuel out no matter how full the crank case is, that seal needs to be replaced.
Could catch. I didnt read or process that part.
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if the welch plugs have been messed with, or there is any corrosion under them that's pushing them out, it will cause flooding issues.
this is the same saw as the Husqvarna 40-45-49. ....
I don't think so, as I recall it those Huskys are Swedish made - while the 2040 is a cheaper Poulan made saw, similar to the Husky 41.