Poulan 2150

[2Twannabe]

I know this is a throw away saw, but I bought it new 14 years ago and after making both H and L a little richer, it's performed flawlessly ever since. Now it's getting a little tired, actually it barely runs. I pulled it apart after measuring compression at 90 psi with a standard automotive gauge. Surprisingly, the cylinder is straight and the piston looks okay. I measured the ring end gap at .035. I'm thinking throw a new ring in it and see what happens.

BTW I thought 90 psi seemed extremely low, so I checked the compression on a new Hitachi CS33EB and only got 100 psi and it runs fine. Go figure.

 

[Dan_IN_MN]

I know this is a throw away saw, but I bought it new 14 years ago and after making both H and L a little richer, it's performed flawlessly ever since. Now it's getting a little tired, actually it barely runs. I pulled it apart after measuring compression at 90 psi with a standard automotive gauge. Surprisingly, the cylinder is straight and the piston looks okay. I measured the ring end gap at .035. I'm thinking throw a new ring in it and see what happens.

BTW I thought 90 psi seemed extremely low, so I checked the compression on a new Hitachi CS33EB and only got 100 psi and it runs fine. Go figure.

Welcome to AS!

With any 2 stroke you should be seeing around 150 psi compression. Are you pulling the rope until the gauge stops increasing?

Yes, you can put a new ring in that little saw and give it new life.

 

[2Twannabe]

Welcome to AS!

With any 2 stroke you should be seeing around 150 psi compression. Are you pulling the rope until the gauge stops increasing?

Yes, you can put a new ring in that little saw and give it new life.

Yes, I stopped counting at 32 yanks.

I was just looking at the parts list for the 2150. It shows the same part number for types 1-5 and a different part number for type 6 and yet another part number for type 7. I don't know which one I have. The tag is not entirely legible any more. It has 2150 on one side of the saw and Woodsman on the other. I think I can safely assume it's not a Predator, but I'm not sure what I have.

Any thoughts?

 

[Guido Salvage]

I know this is a throw away saw, but I bought it new 14 years ago and after making both H and L a little richer, it's performed flawlessly ever since. Now it's getting a little tired, actually it barely runs. I pulled it apart after measuring compression at 90 psi with a standard automotive gauge. Surprisingly, the cylinder is straight and the piston looks okay. I measured the ring end gap at .035. I'm thinking throw a new ring in it and see what happens.

BTW I thought 90 psi seemed extremely low, so I checked the compression on a new Hitachi CS33EB and only got 100 psi and it runs fine. Go figure.

That may be your problem, you need a gauge with a Schrader valve on it.

[EDIT] For kicks I went out and did a quick test on a Poulan 5200. With an automotive gauge I could only get it to go to 105 pounds, but with the one with a Schrader valve it read 165. The latter is brand new so I think it is probably good.

 

[2Twannabe]

That may be your problem, you need a gauge with a Schrader valve on it

It's a screw in Craftsman compression tester and it does have a Schrader valve. I've had it a good many years. I think it may be time to buy a new one or at least compare it to another one. Seems suspicious that my old Poulan is at 90 and a new HItachi is only 100.

I checked a McCulloch PM700 with the same tester and it measured 120 with a completely crapped out piston in it.

 

[2Twannabe]

I'm also really curious about the bare aluminum bore and what appears to be a chrome plated piston. I assume it has to do with keeping manufacturing costs down, but could it really be any cheaper to plate a piston than a bore?

 

[Chris-PA]

The PoulanPro variants had a chrome plated bore, so I guess it must have been a cost issue.

 

[2Twannabe]

I finally got around to putting a new piston ring in the old 2150 and now I'm getting 120 psi compression out of it. I think my compression tester reads a little low, but the point is I went from 90 to 120 and it sounds and runs much better.

 

[diggers_dad]

I finally got around to putting a new piston ring in the old 2150 and now I'm getting 120 psi compression out of it. I think my compression tester reads a little low, but the point is I went from 90 to 120 and it sounds and runs much better.

And that is what this place is all about, just enjoying getting some old equipment running again with your two hands. Good work - hope you get many more years out of it!

dd

 

[galde]

I periodically remove and clean the shrader valves in my comp. testers. They tend to get gummed up by the fuel mix that gets pumped past them. If they get sticky, then your reading will be low by the amount of pressure that it takes to push them open.

 

[2Twannabe]

I periodically remove and clean the shrader valves in my comp. testers. They tend to get gummed up by the fuel mix that gets pumped past them. If they get sticky, then your reading will be low by the amount of pressure that it takes to push them open.

Good point. I wonder if you can buy new valves for compression testers? Just for grins, I took the valve out of my tester and compared it to one out of an inner tube. The valve from the compression tester seemed to have a much weaker spring than the one from the inner tube. I figure it probably wouldn't be a good idea to throw just any old Schrader valve in a compression tester.

 

[Chris-PA]

Here's some shots of a 36cc engine I did a bit of grinding on:

Because the bore is smaller the transfers are pretty large :

I'm waiting for a new ring to show up. I have no idea how many hours this thing had on it but the ring was so worn thin it must have been a lot. The bottom of the piston and the inside of the cylinder were amazingly clean. Just goes to show that if you take care of them they will last a long time. Now it will be ported and it's getting a new bottom end from a straight-gassed PP262 with low hours. I have a lot of time running the 42cc engines and I'm very curious as to how a ported 36cc engine will run.

 

[grantwolland]

Don't forget the Muff Mod!!

Ive redone two 2150's that were given to me. I widened both the intake and exhaust on them and Opened up the mufflers. I run 18" bars on them after that! better on the back for limbing and really doesn't bog them down until they meet 16" of hardwood...then i just take it slow with a sharp chain. But then again i also put a bucking spike on them so the extra bar gets a little shorter with the spike. But impossible to beat that kinda bang for the buck! Usually a complete rebuild costs less than 50 bucks in parts and that's with a new sprocket!

to the OP...the type is found in the EPA number on the tag ifn it's legible at the end looking like -x where x is the type number. shouldnt really make a difference. but they should have a chrome bore and aluminum piston...I have yet to see anything different and thats from several 36cc-42cc models. but they are the older ones till mid-late nineties. I would think a cast ring would chew up an aluminum bore pretty quick when she gets warmed up. But then again briggs has done it for years.

 

[fearofpavement]

That may be your problem, you need a gauge with a Schrader valve on it.

[EDIT] For kicks I went out and did a quick test on a Poulan 5200. With an automotive gauge I could only get it to go to 105 pounds, but with the one with a Schrader valve it read 165. The latter is brand new so I think it is probably good.

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I have seen comments similar to this several times on AS and have no idea what is being referred to. I'd like to see a pic of a compression tester that doesn't have a valve in it. (other than the kind you "hold" against the spark plug hole.

 

[Chris-PA]

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I have seen comments similar to this several times on AS and have no idea what is being referred to. I'd like to see a pic of a compression tester that doesn't have a valve in it. (other than the kind you "hold" against the spark plug hole.

I have one of those, and it has a Schrader valve too. I think they all do.

 

[fearofpavement]

Good point. I wonder if you can buy new valves for compression testers? Just for grins, I took the valve out of my tester and compared it to one out of an inner tube. The valve from the compression tester seemed to have a much weaker spring than the one from the inner tube. I figure it probably wouldn't be a good idea to throw just any old Schrader valve in a compression tester.

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You are correct that the valves are different even though they will interchange physically. I tried it and a tire valve core won't work.

 

[2Twannabe]

Ive redone two 2150's that were given to me. I widened both the intake and exhaust on them and Opened up the mufflers.

How are you modifying the mufflers on the older 2150s. They're straight through already. About the only thing you can do is make the outlet holes bigger, right?

 

[grantwolland]

i gut them good!

ill take a cut-off wheel and cut out the baffle inside making the rows of holes into a big hole and then braze a deflector over another hole i put on the side. I'll try to get a pic ifn i can. i stay away from holes in the front of the muffler, doesnt put the exhaust where i like it and it can get some debris when bucking.

 

[Chris-PA]

How are you modifying the mufflers on the older 2150s. They're straight through already. About the only thing you can do is make the outlet holes bigger, right?

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