Poulan 3450 Project Saw - More Questions

[Log Splitter]

I was not getting fuel to the cylinder in my old 3450, so I ordered a carb kit, new fuel line, impulse line, and fuel filter. While waiting on the parts, I went ahead and disassembled the saw and found the problem. (Broken impulse hose at the crankcase fitting.) Since the parts had not arrived, I went ahead and put the saw back together and planned to rebuild the carb later.

The saw still will not start. Before I had a dry plug and good ignition but it would not run. Now I have a wet plug and good ignition, but it still won't run. The starter seemed too easy to pull, so I did the 'drop test' and the saw wound out all the starter rope.

So, I pulled the jug and found the rings were stuck with carbon coating the piston and crusted in the top of the head. I've been cleaning all that mess up today (the cylinder wall does not look bad) and now I'm waiting on a ring and new gasket to arrive along with my carb parts.

My question is regarding the build up of light brown material (more carbon ?? ) down in the crankcase. In the attached picture, just above the crankshaft, you can see where the deposits have built up to the point they are flaking off. Since this stuff is hard, I can't think it would be good if more of it flaked off while the saw is running. Should I try to clean it off? If I do, then there is no way to keep it from getting down into the bottom of the crankcase which will make the cleanup/removal process a real bear, and I really don't want to split the case.

I thought I'd done a fine job cleaning up the old saw, but the macro lens on the camera helped point out some more grime, didn't it.

 

[Log Splitter]

Anybody????

Looking at it again this morning, I wonder if the 'coating' might be paint. They wouldn't paint the inside of the case, would they?

Since this is my first time to tear down and rebuild a saw, I'm just wondering what most people do to clean out the crankcase after they get done working on the top end. It can't be a good thing to have debris running around in there after the saw gets going again. Also, would it be a good idea to put a bit of 2 cycle oil on the bearings before I put it back together?

Sorry for the newbie questions, but if it were not for AS Site this saw would be at the dump with all my other old saws. After reading all the posts here I got interested in trying to fix up an old saw just to see if I can bring one back. I've not spent much money on the parts so far, but I have put some time into the project. I'd also like to get it running again so I can compare it to my new MS270 in some fresh cut hickory this weekend.

 

[bump_r]

Looks like the same crap that gums up a carburetor in automotive applications. As such, my first though would be to douche it out with a good carb and choke cleaner. Be sure to pre-lube the bearings before you button it up.

 

[scottr]

Log Splitter , if I were you I'd take a flake of that brown stuff and see if my gas/oil mix would disolve it in a jar . I've never heard of Poulan painting the inside of their crankcases but you can get the factory phone number from ordertree the parts phone number on your saw and give them a call . That crankcase looks like it had some crappy mix run through it .

 

[Four Paws]

It looks like varnished gas to me! Fill the crank up with gas and let it sit for a few hours/over night. That 'brown stuff' will wipe right out of there.

Looking like you will have a nice performing saw - you are doing everything a guy should to 'freshen' his saw up.

Josh

 

[Log Splitter]

Thanks, guys. Not that you mention it, varnish makes a lot of sense for being the source of the deposits in the crankcase. All I know about working on 2 cycles is from searching on AS, so some of my questions may be a bit basic.

I can't say I ALWAYS run fresh mix in the saw. I try to, but it stays at my camp which is 700 feet off the road in the woods in Louisiana. Sometimes when you don't expect to be running a saw you find yourself having to use whatever gas is still around, like the time I got there about midnight and a tree was down across my road leading to the house.

I'll fill up the crank with premix and let it soak. I have plenty of time, I checked this morning and the new piston ring and gasket have not shipped yet. I suppose the holidays have slowed them down.

I hope the saw runs when I get done. The funny thing about all this is last year was the first time I ever did anything to 'store' the saw properly. It was running fine the day I put it on the shelf. Of course, from the looks of all the built up carbon that was on the piston and cylinder, it was just a matter of time....

 

[1wildthing]

Instead of premix, I would use either straight gas, or alchohol would be better. Simply because they will dissolve the stuff more easily.

 

[Log Splitter]

It cleaned up real nice. Thanks, gentlemen!

If you spend your holiday vacation rebuilding an old chainsaw, you might just be a ...... :hmm3grin2orange:

 

[Four Paws]

Now, lube those crank bearings up with some 2-stroke oil and rotate the crank around a few times for good measure.

 

[Freakingstang]

Instead of premix, I would use either straight gas, or alchohol would be better. Simply because they will dissolve the stuff more easily.

Negative Batman... alcohol will eat the seals, and if it doesn't completely eat them, it will dry them out to where you have an air leak, ask me how I know...


Premix, or straight 2 stoke oil.....

 

[buck futter]

I think you should open up the muffler a little.
if your exhaust is free than you have more effective blowdown with out touching the ports. look for screens or a choked up muffler while you are at it.


I would like to see the piston and cylinder if you wouldn't mind.

Buck

 

[Log Splitter]

I think you should open up the muffler a little.
if your exhaust is free than you have more effective blowdown with out touching the ports. look for screens or a choked up muffler while you are at it.


I would like to see the piston and cylinder if you wouldn't mind.

Buck

My plan is to get the saw up and running 'as is', then open up the muffler the same way Cut4Fun did on his Poulan the other day.

Here is a picture of the piston and cylinder. I'll post a better one once the dry cycle ends. I don't have any 'before' shots, wish I did....

 

[buck futter]

I don't see a pic.

Ok thats fine, I guess you would have a better before and after but I would see if there is anytype of screen. I think they have a basket inside the would be a big help removed.

Buck

 

[Log Splitter]

I don't see a pic.

Ok thats fine, I guess you would have a better before and after but I would see if there is anytype of screen. I think they have a basket inside the would be a big help removed.

Buck

Ah! I did not understand you wanted to see the muffler too. It's not in the dishwasher, the bride might run me off if I did that. Here you go, this one is with the front plate removed.....

Here is the muffler with the parts all laid out in order....

I think I can remove the basket with the two square cutouts and simply leave the screen in place. At the very least I'll drill out some more holes. The other mod I think Cut did was to either pry out the exhaust openings on the front plate or drill two 1/2 inch holes in it.

The interesting thing to me is the screen was not stopped up, despite the fact that the piston crown and top of the cylinder were caked in carbon. Also, the inside of the muffler (past the screen) is caked in carbon. That makes me think that the size of the carbon particles is smaller than the screen openings.

 

[scottr]

3450 Muffler

If you soak the baked on carbon with some detergent motor oil it will soften and you can wipe it out . If you take the diffuser box out then the screws that tighten the front to the back of the muffler can distort the cover . If you remove the spark arrestor screen and open the outlet hole in the back to your liking the chance of a spark is slim and the log doesn't get hot as with holes drilled in the front .

 

[Log Splitter]

If you soak the baked on carbon with some detergent motor oil it will soften and you can wipe it out . If you take the diffuser box out then the screws that tighten the front to the back of the muffler can distort the cover . If you remove the spark arrestor screen and open the outlet hole in the back to your liking the chance of a spark is slim and the log doesn't get hot as with holes drilled in the front .

Good thought on distorting the cover with the diffuser box removed. I may just go back with some spacers to prevent that from happening, but leave the screen in place. I'm not worried about setting the woods on fire as much as I am getting some dirt into the cylinder if I remove the screen. I'll also pry open the front exhaust outlet on the front cover like you suggested rather than drilling holes. Makes sense. Thanks!

 

[scottr]

Front cover

I thought that the 3450 muffler outlet was on the rear of the muffler and was deflected to the side and forward by the shield . I used some small copper tubing cut to the diffuser length to eliminate the diffuser box .