266xp vapor lock?

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stonykill

stonykill

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Today was the 1st warm day that I had a chance to cut wood. I grabbed the 266xp, 346xp, and old reliable, the 10-10. The 266 ran great for 1/2 a tank, then died. Filled the tank up , it started hard, way to many pulls, had to choke it hot to start it, slowly bringing in the choke. Then it ran great again, until 1/2 a tank. I went through this cycle 3 times, it was either run over the saw or grab the 10-10. Of course the 10-10 gave me no problems and finished off the day without issue. I got home the 266 was cool, filled the tank, started right up, ran great till 1/2 a tank, then the same thing. Is there a vent somewhere in the 266 that could be plugged? Any ideas would be real helpful. Thanks>>>Tom
 
First off,I'd replace the fuel filter,and make sure it's not bound up somewhere in there.It seems odd that it happens at a half tank of fuel...So that's the first thing that comes to mind...I once had a 044 do the same thing.
 
You might want to check you fuel tank vent for blockage and your fuel line for cracks. Also as Timberhauler said, a new fuel filter is not a bad idea either.
 
The tank vent slipped my mind...I've never even had a tank vent problem...But you guys are right...Good idea.
 
the fuel line looked fine, however I reallize they can look fine, but still have pinholes. I should have time to take it apart over the weekend and check it out further. I did pull the top cover last night and saw the coil wire had 2 jug melts on it. I don't think thats my issue but it can't be good so I'll fix that 1st. It sure acts like a vapor lock. I'll find the tank vent and clean it, and most likely just replace the fuel line and the filter while its apart. I like to work on saws, but not when I need to work with my saws, so I'll just check it all out. thanks guys>>Tom
 
Check vent, change filters, gas and air, change plug. All easy and cheap. If that doesn't work try a carb kit installation. But do the easy stuff first. Check that your chain isn't jamming when it gets hot, sprocket, bar, oiler, etc. are okay. I'm curious to know what fixed the problem. Sure sounds like a fuel, carb, air combo issue.
 
DGG said:
Check vent, change filters, gas and air, change plug. All easy and cheap. If that doesn't work try a carb kit installation. But do the easy stuff first. Check that your chain isn't jamming when it gets hot, sprocket, bar, oiler, etc. are okay. I'm curious to know what fixed the problem. Sure sounds like a fuel, carb, air combo issue.
Click to expand...


its not the chain binding, oiler is fine. I'll let you know what fixes it. I'm way behind on my jobs, so it may take a bit to get to it,thanks
 
Make sure the plug on the firewall of the top cover is in place.Also make sure your cylinder fins and starter cover are as clean as possible.266s were more vulnerable to vapour lock owing to the solid manifold. All new generation pro saws now use rubber boots as manifolds,does a much better job of keeping heat away form the carb. As soon as the airbox temp reaches around 44deg c
gas will vaporize inside the carb and bingo,no more runnin noises!
 
jonseredjohn said:
Make sure the plug on the firewall of the top cover is in place.Also make sure your cylinder fins and starter cover are as clean as possible.266s were more vulnerable to vapour lock owing to the solid manifold. All new generation pro saws now use rubber boots as manifolds,does a much better job of keeping heat away form the carb. As soon as the airbox temp reaches around 44deg c
gas will vaporize inside the carb and bingo,no more runnin noises!
Click to expand...

thats some good info. Everything was and is clean. I keep my saws nice, blow them out after every outing. I just put a new rope in it, so I know the starter is also clean. thanks for the good post.
 
The 266 was infamous for vapor lock. There is/was a kit that helped. It included stainless steel carb mounting bolts that had plastic sleeves to go over them in an attempt to keep heat transfer from the manifold to the carb to a minimum.

Sometimes, A simple cure is to switch gasoline brands. Alcohol in gas will lower the temp at which it will vapor lock.
 
:rock: ok, finally had a chance to check it out. Fuel filter was pretty plugged. Changed fuel filter and line, cleaned the vent. Noticed that the heat shield on the side of the muffle was missing and fabricated one to replace the missing. Without it, the heat from the exhaust was not only melting the chain break handle, but was also dumping hot exhaust gas into the cylinder area, under the top cover. Made a few cuts and feels good. After lunch I'm going to attack a huge for this area maple, around 40 inches at the base. Its 55 degrees here today, and the tree is big, so I'll know soon enough if its fixed. I think the main problem was the missing heat shield. I'll know soon enough. Thanks all for the feedback, and I'll check in later with the cutting results, and maybe a few pics.>>>>Tom:D
 
The saw ran like a champ. I wish I had time to diagnose it one step at a time, but this is my busy season, so chainsaw time is limited. I am sure it was the lack of the muffler heat shield that was the problem. It got so hot under the top cover that the plug wire was melted to the jug!:( . Its all good now, a few pics of part of the days work. The 1st 2 are after it was limbed, the 2nd 2 pics are after 1 full tank thru the 266. I forgot to take any pics after that. I think I'll be able to mill the 1st 6 feet of this tree, I'll know better next time I go there to cut.

DSCF0568.JPG


DSCF0569.JPG


DSCF0570.JPG


DSCF0571.JPG


:chainsaw:
 
there are a lot of good tips here. (well most of 'em ) there is a possibility that you could have a heat sensitive ignition system too:bowdown:
and maybe in need of the latest design muffler exhaust gasket that helps lower the exhaust port temp:clap:
 

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