What is wrong with my 025?

[game04]

My 025 starts and idles ok and when I ease onto the throttle it goes up to max speed with no problem. However when I mash the throttle it immediately dies. When I bought the saw last month it would not start so I took the carb apart and cleaned it. All the gaskets and diaphragm looked to be in pretty good shape so I didn't replace anything. The carb just has a low speed screw and idle screw. The low screw is turned out one turn. Any ideas what the issue may be?

 

[sawbid]

Check the little rubber impulse line and port...that is the easiest fix. If not that, could be an air leak somewhere.

 

[Fish]

Go through the carb again, this time remove the needle/spring/lever combo
and hold the carb body up to a light, then blow out all of the orifices again
including the passage under the needle, then hold up to a light again, and
visually verify that the passage is clear.

Also visually inpect the fuel line for cracks, especially between the tank and carb. also make sure the impulse line is in place and tight fitting.

 

[stevohut]

My 025 starts and idles ok and when I ease onto the throttle it goes up to max speed with no problem. However when I mash the throttle it immediately dies. When I bought the saw last month it would not start so I took the carb apart and cleaned it. All the gaskets and diaphragm looked to be in pretty good shape so I didn't replace anything. The carb just has a low speed screw and idle screw. The low screw is turned out one turn. Any ideas what the issue may be?

Sounds like your low speed is to lean. That's what happens she boggs when you tromp it until the mid and high speed circuits take over. If you got a lim cap on that low speed pull it off and back your screw out to richen her up. This will bring down your idle so adjust accordingly. Failing that you have a carb issue and further investigation is needed. The saw may also have an airleak that could cause this problem. The saw will have a high idle if an airleak is present that would be hard to regulate with the idle and low speed jets. Those little diaphram carbs can be very fussy so its important to have all the orfices extremely clean or it will keep you running in circles trying to figure it out. make sure your fuel filter and tank aren't full of crap. easiest way to find an airleak is start the saw and let idle take a propane torch with a rubber hose on the end of it. open the valve to let some propane out. move the hose around all areas that could leak. if the idle goes down in a certain spot you have found your airleak. old trick for testing carbs and manifolds on cars for leaks. Check your hoses too make sure your getting fuel and a negative pressure from your pulse line. Hope this helps

 

[a. palmer jr.]

Sounds like your low speed is to lean. That's what happens she boggs when you tromp it until the mid and high speed circuits take over. If you got a lim cap on that low speed pull it off and back your screw out to richen her up. This will bring down your idle so adjust accordingly. Failing that you have a carb issue and further investigation is needed. The saw may also have an airleak that could cause this problem. The saw will have a high idle if an airleak is present that would be hard to regulate with the idle and low speed jets. Those little diaphram carbs can be very fussy so its important to have all the orfices extremely clean or it will keep you running in circles trying to figure it out. make sure your fuel filter and tank aren't full of crap. easiest way to find an airleak is start the saw and let idle take a propane torch with a rubber hose on the end of it. open the valve to let some propane out. move the hose around all areas that could leak. if the idle goes down in a certain spot you have found your airleak. old trick for testing carbs and manifolds on cars for leaks. Check your hoses too make sure your getting fuel and a negative pressure from your pulse line. Hope this helps

That's about what I was thinking..You might have your idle set too slow. You don't want it fast enough that the chain turns but just below that point. Then turn your L screw about 1/2 a turn to see if it makes it better. If it makes it worse turn it back.

 

[game04]

Ok, I got it running good now. I took the carb back off and I noticed the choke rod was slightly bent. I also sprayed out the carb again and put a newer metering diaphgram on in. I'm not sure which one it was but it's responding perfect to the throttle now.

My only question now is with the fuel vent. I noticed when I shut the saw off there was fuel on top of the fuel tank. It is seeping out of the top of the fuel along with some air bubbles. Is this normal? I also noticed when I turn the saw on its side (rope starter side down) fuel slowly drips out of the top of the vent tube? This doesn't seem right. Both grub screws are present and I tried two different tubes from other 025's and it does the same thing.

 

[sawbid]

a little "seepage" is normal and should be expected when the vent is completely covered by fuel. As the fuel vaporizes laying on its side like that, it will build up enough pressure to "push" a little fuel out the vent...as long as it is just a trickle and not pouring out, in my eyes, it means your vent is doing its job.

 

[game04]

Thanks guys for the help. I think this means this saw is finished. I just have 6 more to work on now.