HELP! Poulan Pro PP295 - Air Leak or Carb Issue?

[Clarkbug]

Evening everyone.

I had posted over in the Poulan thread, but figured I would ask here in the general forum also. (sorry that its long winded, wanted to get as much info as might be helpful out there)

I picked up a PP295 for a few bucks at a flea market last fall, and recently tore into it. Other than being filthy, it clearly needed fuel lines and an air filter, and I assumed a carb kit. I put in a new fuel line, fuel filter, air filter, and a carb kit. The screen in the carb was filled with sawdust, and I put in a new needle from the kit. I didnt pull the welch plug, but wondering if I should have. Pulled the limiters off, and aside from having to turn both the H and L screws out more than expected, it fired up and ran pretty well I thought.

I used it for a few cuts, and put it away for the day. Next day went to go use it to try it out a bit more, and the idle was higher. I figured I just needed to adjust a little, and started fiddling, but after a few more cuts it seemed like I wasnt able to find a good spot for it to run and then it wanted to run away. So, my guess is that there was an air leak and I shut it down for more diagnosing.

Pulled it apart again tonight. Piston and cylinder look great, so doesnt appear to be any damage. From looking under the clutch, I am guessing someone has been here before me. There is black sealant thats a little sloppy on the clutch side, and I noticed some on the fins of the cylinder (figure that wouldnt be factory). The flywheel side doesnt look like there is any extra squeeze out at all. I did notice it has what just looks like a plastic seal, so I guess this is the two piece setup where I dont need to do bearings also.

Given the history of these kinda saws, and that someone looks to have been here, is it a pretty safe bet to just put seals in it? I did notice there is a cut along the bottom of the silicone intake boot for the pulse line, but it doesnt go all the way through. Cannot see where else there would be a chance to have a leak, unless its because I re-used the gasket between the carb and the metal plate that seals up against that boot.

Or, is there something that could be up with my carb rebuild that would make it hard to actually tune? I have usually started my screws about 1 1/2 turns out, and this was 3 1/2 to start.

Appreciate any insight before I just fire the parts cannon. (I know thats hard to do without being here and looking at it)

 

[hacskaroly]

I have learned when getting a saw with unknown history (use, length sitting without use...etc), I find it best to just go ahead and replace the seals, I have learned the hard way and burnt two pistons that way (trying to be cheap and fix only what I thought needed fixing). Replacing the oil seals will give you an opportunity to inspect and extra lube the bearings while you are there. While not a hurry, I think it would be worth it to replace the cut boot before it does create a hole (insurance and one less issue to chase).

Not sure what is up with the black sealant (I am trying to picture what you have going on), but it is possible someone is trying to mask an issue or or something. Might be worth digging into it and see if there is an air lead that can be resolved with a proper gasket or replacing a cracked part. I have an older saw that the crankcase was hit by the chain hard enough that it cracked through the case and they sealed it with a piece of aluminum and some clear type glue. It seemed to work, but was not the proper fix which I am working on something more permanent.

 

[Clarkbug]

I have learned when getting a saw with unknown history (use, length sitting without use...etc), I find it best to just go ahead and replace the seals, I have learned the hard way and burnt two pistons that way (trying to be cheap and fix only what I thought needed fixing). Replacing the oil seals will give you an opportunity to inspect and extra lube the bearings while you are there. While not a hurry, I think it would be worth it to replace the cut boot before it does create a hole (insurance and one less issue to chase).

Not sure what is up with the black sealant (I am trying to picture what you have going on), but it is possible someone is trying to mask an issue or or something. Might be worth digging into it and see if there is an air lead that can be resolved with a proper gasket or replacing a cracked part. I have an older saw that the crankcase was hit by the chain hard enough that it cracked through the case and they sealed it with a piece of aluminum and some clear type glue. It seemed to work, but was not the proper fix which I am working on something more permanent.

Thanks for the reply!

Here is a photo that I took before I pulled everything apart. You can see the sealant at 2 and 9 by the crank. I think this uses the separate seals and bearings, but will need to open it up to confirm.

I'm going to buy the kit that has the intake boot, carb adapter and gaskets to eliminate all of my possibilities.



I'll also need to get something together to pull the oiler worm gear.. not sure of the thread pitch yet

 

[hacskaroly]

I'll also need to get something together to pull the oiler worm gear.. not sure of the thread pitch yet

The thread pitch should be 1/2" pipe thread (if I remember correctly), I have a Husky 55 with that set up and built my own puller from a coupling and nipple - I will have to try to remember to look at it when I get home. Here are two videos showcasing home built pullers, who knows, you may already have these parts on hand:

Now that I look at the IPL, this Poulan is basically a Husky 55, it has a clamshell cylinder which requires using a sealant between the cylinder and the base plate. Some people even put it around the bearings too to prevent air leaks, so I would say that black sealant is supposed to be there. If you do remove the cylinder, you will need to clean off all of the old sealant and replace it with new sealant that is fuel resistant....this is very important, was chasing my tail on my saw until I realized I was using the wrong sealant!!

The diagram below with the red arrows show the base plate and the cylinder where you will be placing the sealant (no cylinder gasket on this saw).

 

[Clarkbug]

I actually was just watching those same videos. Wasn't sure if it was the same setup, so Ill need to see what I have for fittings in the random pile in the basement. Any thoughts on putting it back on there in the right spot?

From what I have found, this is similar to a Husky 41/141, don't know how similar those are to a 55, but the same basic layout. I do think the black sealant is supposed to be there, but it seems a little sloppy on there, so makes me think I wont be the first to try and fix things. Was planning to use Motoseal for the replacement when I stick it all back together.

 

[hacskaroly]

Any thoughts on putting it back on there in the right spot?

Just put the makeshift tool back on and tap it until it seats. Yeah, the 36/41/51/55s are basically the same thing, just different sizes. I find it tough when putting the goo back on not getting too much - squeeze out on the outside is not an issue, you just don't want too much oozing inside and then getting thrown around, just makes a mess.

 

[Clarkbug]

Just put the makeshift tool back on and tap it until it seats. Yeah, the 36/41/51/55s are basically the same thing, just different sizes. I find it tough when putting the goo back on not getting too much - squeeze out on the outside is not an issue, you just don't want too much oozing inside and then getting thrown around, just makes a mess.

Update after lunch.

Pulled the gear off. a 3/8" fitting fit, but only a few threads. That and some screwdriver action seemed to help, will need to drive it back on more carefully.

Seals appear to have been leaking. I think someone put the sealant on them also, and it doesn't look like it stayed put. Or at least it didn't bond to the metal and the rubber/plastic on the seal surface. There is a lot of what looks like uncured sealant, maybe just regular black RTV was used and not something fuel safe. Im going to order a new set of seals along with the carb holder/intake boot and the bar oil fitting and will try to get this back together.

Any tips on order of operations for the sealant? Apply some to the cylinder, let it set up a little, then stick in the seals and tighten down the crankcase cover? Tighten the screws right away or give it a minute to set? Sorry, first time in a clamshell...

 

[hacskaroly]

Any tips on order of operations for the sealant?

Follow the instructions on the tube, I know others use Dirko, I think I have another brand, maybe Permetex, can't think of it off hand, basically with the stuff I have, you clean all surfaces very well with acetone or something similar, then spread a thin layer on all surfaces that will come together (clamshell bottom, cylinder and bearing pockets. Ease everything together without smearing the sealant, tighten cylinder bolts until the sealant comes together and just starts to squeeze out slightly. Wait one hour and then tighten to torque spec. Let set for 24 hours before running saw.

You want to make sure you get a little extra sealant in the notches where the bearings set, this will greatly reduce the chance of an air leak, usually the stuff flows well against all of the other surfaces, but these pockets on the cylinder and the base plate need a little extra.

Sorry, first time in a clamshell...

No worries, clamshells take a little more time to work with than standard cylinders as you have to wait for the sealant to dry before testing and that can add a couple of days if you goof up and have to redo it. Keep asking questions if you have them!

 

[Clarkbug]

Keep asking questions if you have them!

Thank you!

And thanks for the picture, that's helpful. I think on my saw those notches hold the edges of the seals, and the bearings ride just inside of those. (the IPL shows there are two different configurations of bearings/seals, mine is the one with separate pieces) I guess I can try to get sealant in that entire notch, but don't want to have too much goo all over the place inside the saw. I also see Motoseal isn't recommended for plastics, which the outside of this seal seems to be...

 

[hacskaroly]

Dirko HT is highly recommended as fuel, heat (up to 315 C) and plastic safe. You don't need the sealant in the entire notch, just where the cylinder and base plate come together, with the seams and the seals meet up...there is the greatest chance of air leak. Trying to find a happy medium is the trick, too little and you can get an air leak, too much and you have a mess and dirko balls bouncing around the cylinder until they are spit out and captured by the muffler.