Freeing a frozen/sized piston

[GarageEnvy]

Alright you guys can all have a good laugh at my expense. I haven't torn down too many engines and it's been a long time since I've done it. I've got a Partner K950 cutoff saw that I'm trying to sell but I can't get it to turn over. I bought this thing about a year ago and made a single cut with it. The thought was that I could sell it for about what I paid and save the $300 in concrete cutting fee. I stuck the thing in the shed and it worked when I put it in there. Now a year later there's just no pulling that cord. I took the spark plug out to see if it was a compression release problem but no luck. I tried a little WD40 down the cylinder but no luck. Since this is a saw I'm trying to sell instead of keep I'm not looking to make a project out of tearing it apart.

So here's the stupid question. How dumb of an idea would it be to stick a wood dowel down that spark plug hole and give it a whack? At this point my thought is that since it is a wet saw some water got down in there and rusted the piston to the cylinder. I know the gas was mixed correctly and it was running when I stored it so I don't think it's a usage/heat seizure.

 

[LEVE]

Try a little PBblaster soaking the piston and rings.

Then... a can of Coke Cola!

 

[trbomax]

heat it from the top only on the pin edges. 2 cylye pistons are not round . They expand more around the ports,and usually sieze there too. If you heat it around the pins,it may contract on the port sides. Then whack it!

edit) just reread the op. Is the jug and head intragal (one piece) ? That complicates it,but if you could pull the jug and heat around the pins from the bottom it might be ok.

 

[bochnak]

Marvel mystery oil in plug hole. If that doesn't work, pull the muffler and carb and apply more oil.

 

[tonydanzah]

fill the cylinder with 50/50 mix of acetone and atf. Give it a day, then talk dirty to it.

 

[tatra]

have heard diesel fuel works too, never tried it............

 

[HDNewf]

One thing to keep in mind is that a single cylinder 2-stroke piston will likely be stopped near bottom dead center. Whacking it with a dowel rod may just add wood chips to the cylinder. I would use light oils as mentioned above to try and free it. Is there any access to the crank output that you could turn it with?

 

[tdkkart]

Get a wrench on the other end of the crankshaft and gently try rocking it back and forth. Between possible water and a bit of humidity, it may have rusted the ring to the cylinder wall.

Good practice with any engine is too let it idle for a few seconds to a minute or so with no load before storage. Especially things like concrete saws, chain saws, etc get run hard then simply switched off, leaving their cylinder walls very dry.

 

[Jallred]

Finaly a small engine problem on the fourm. I work on these. The last poster is correct about the wrench idea. While it is ok to put a LITTLE light oil down the cylinder do not put coke,ATF, or realy anything else down there. Unlike an engine with an oil pan that all that can be cleaned out of, small 2 cycle engines have a more or less sealed crankcase that the fuel air mixture must pass through when the unit is running. Any of these fluids will collect in the crank case and cause problems. If it is stuck so hard that the wrench will not turn it then you probabaly have larger problems that may require the removal of the cylinder. Hope this helps. If you have any more questions let me kinow.


Jason

 

[LARSOFVT]

I can't believe the piston could be rusted up after only one year. Did you check the blade to make sure it's not hung up?

 

[brianh]

Check the clutch the shoes and housing are steel the concrete dust may have rusted it, does the cutoff wheel turn if it does it probably is not the clutch.

 

[rsanter]

I think soak the cylinder with oil. put it in the spark plug hole and let it sit untill it frees up

bob

 

[NUTTSGT]

Does that thing have a compression relief button ? That makes a world of difference.

 

[GarageEnvy]

It does have a compression relief valve. That's the reason I removed the spak plug. And yes, if that is not depressed then good luck starting it.

Also, for the record I'm not quite as retarded as the title of the thread would indicate. I just can't go back and correct the sized to seized.

 

[NUTTSGT]

It does have a compression relief valve. That's the reason I removed the spak plug. And yes, if that is not depressed then good luck starting it.

Just wanted to make sure you remembered it. There's been more than one time I grabbed ours at the FD and started pullin gbefore I remembered the decomp relief.

 

[BillK]

GE,
If it ran ok a year ago, more than likely it is just gummed up fuel causing the issue. Seems like the fuels with ethanol in them start turning to glue after sitting for a while. I would try some PB blaster first and rocking it back and forth like someone else suggested. If that does not work, get some GM Top Engine Cleaner and pour about a half cup of it into the cylinder with the engine sitting with the cylinder vertical. Let it sit for a few hours, then turn it over with the spark plug out and see what happens. If that does'nt do it, yo will probably have to take it apart

 

[Skin]

Sure nothing is jamming the flywheel? Maybe a squirrel or mice found a nice place inside to store things. I find it very odd that a piston would get frozen in place in that short amount of time without scoring or something jamming the recoil/flywheel.

 

[jon1996]

To free a seized Engine nothing is as good as Turpentine, yep plain ol Turpentine, just pour it down th eplug hole wait about a hour and it will be free a a bird, you can thank me later

 

[Skin]

you dont want to use anything thats going to strip the cylinder walls of every trace of oil on a 2 banger...

Theres often no way to drain the engines either so its going to sit in the crank and anything flammable that pools in there could potentially blow out the crankshaft seals.

 

[Joe69]

Remove the recoil and try to turn the flywheel by hand. I've seen many concrete saws that had the recoil stuck due to concrete dust.

Joe

 

[KenS]

Unlike an engine with an oil pan that all that can be cleaned out of, small 2 cycle engines have a more or less sealed crankcase that the fuel air mixture must pass through when the unit is running. Any of these fluids will collect in the crank case and cause problems.

Jason

Listen to Jason.

 

[brownbagg]

i had luck with the marvel mystery oil and tapping a wooden dowel. not hard hits but let it soak and evry day tap it to break loose. I have also heard about the acetone and atf trick too. I will try that next time

 

[GarageEnvy]

OK the verdict is in. Thanks to those who suggested rocking back and forth. It took a bit of effort but that did the trick. The PB and WD in the cylinder did nothing and I ended up dumping them back out through the spark plug hole and compression release valve. There is definitely a lot of concrete dust built up in the clutch though. I'll be cleaning it out. Now who want to buy the thing?

Thanks
Richard

 

[Aspen RT]

Wow, it got really quiet didn't it.

 

[santagary]

Kroil creeps...try Kroil in the sparkplug hole! Betcha it works.

 

[tcianci]

Remove the recoil and try to turn the flywheel by hand. I've seen many concrete saws that had the recoil stuck due to concrete dust.

Joe

Bingo, I was wondering when someone would figure out that the piston is not the only thing that could sieze in an engine. I have a 4 stroke Tech engine with a thrown rod. It wouldn't budge...Both the electric starter and the recoil were rusted solid. The funny thing is that the electric starter rusted with the bendix engaged.