Poulan Micro XXV, starts but won't run

[woolleyemmett]

I just got a Poulan Micro XXV from my dad. After much tinkering and a new tank of fuel, i got this thing to fire with the choke on full. Then with the choke set almost all the way on, I can get it to run okay for a while. Then it either dies, or revs up out of control. A buddy took a look at it and said I might be getting air into the crank case. Is this a common problem? Are there certain things I should look for? The other things I should note: I'm getting blow-back of fuel out of the carburetor, sometimes a mist, sometimes a fine spray. Also, I looked at the reed valve under the carburetor body and it does not make a tight seal in it's resting state. I tried removing it, flipping it over, and reattaching it, but it still does not seem to make a good seal. Could that be causing the blow-back and ultimately my problems?

 

[lawnmowertech37]

I just got a Poulan Micro XXV from my day. After much tinkering and a new tank of fuel, i got this thing to fire with the choke on full. Then with the choke set almost all the way on, I can get it to run okay for a while. Then it either dies, or revs up out of control. A buddy took a look at it and said I might be getting air into the crank case. Is this a common problem? Are there certain things I should look for? The other things I should note: I'm getting blow-back of fuel out of the carburetor, sometimes a mist, sometimes a fine spray. Also, I looked at the reed valve under the carburetor body and it does not make a tight seal in it's resting state. I tried removing it, flipping it over, and reattaching it, but it still does not seem to make a good seal. Could that be causing the blow-back and ultimately my problems?

yes the reed valve if there is trash between the reed and the body throttle it will cause a gap big enough to have blow back with fuel i was working on a homelite xl 12 that had the same issue had to replace the throttle handle cause the throttle handle had a cut into the metal part of the reed valve resting area which caused the gap with the reed so with that said its possible that xxv may be the same issue

check for trash between the reed and the throttle handle area if there is none then check for cracks that would cause a gap issue

sounds like your whole issue with the rrev issue is that reed area

cause its not controlling the amount of fuel flow correctly cause of the reed not seating against the handle

hope this helps

calvin


if you find out if you are in need of any parts i have parts for the micro xxv 's

 

[MS460WOODCHUCK]

Them saws are known to get cracks in the gas line at the rear of the handle or where they go into the tank. I had a few that did what u are saying and that was the problem. The cracks were not big just enough to get a little air and they would not run without choke.

 

[almondgt]

Sounds like crank seals to me, just my .02 cents.

 

[woolleyemmett]

Thanks, guys. I checked the fuel line all the way. I don't see any cracks, it really looks like it is brand new. I also checked the crank for any leaks, I can't find any place where it looks like there is oil or fuel coming out of the case, which would lead me to think there is a leak. I think I'm going to try the reed valve first, and see if I can't get that to fix it. If that doesn't work, I'll look into the crank seals a little harder. Also, I was wondering about the fuel/oil mixture. Written on the handle of this thing it says to mix 1/2 pint to a gallon. That's a 16:1 mixture. I like to use Stihl oil which is 50:1. Will I do harm to the saw using 50:1 Stihl oil? And if so, what kind of oil should I buy that is 16:1? Thanks.

 

[lawnmowertech37]

Thanks, guys. I checked the fuel line all the way. I don't see any cracks, it really looks like it is brand new. I also checked the crank for any leaks, I can't find any place where it looks like there is oil or fuel coming out of the case, which would lead me to think there is a leak. I think I'm going to try the reed valve first, and see if I can't get that to fix it. If that doesn't work, I'll look into the crank seals a little harder. Also, I was wondering about the fuel/oil mixture. Written on the handle of this thing it says to mix 1/2 pint to a gallon. That's a 16:1 mixture. I like to use Stihl oil which is 50:1. Will I do harm to the saw using 50:1 Stihl oil? And if so, what kind of oil should I buy that is 16:1? Thanks.

its possible that 50:1 is too much for that older saw those saws for built for a certain ratio

i guess you can get the ones that you can mix according to gallons of fuel used walmart carries that kind of oil so does lowes

i even sell the oregon oil on my store

part # 40092 it is packets but i sold 12 out of 48 already to online customers