250-500cc Froze my WR 250 pipe and blew it apart!

I thought I'd blow out some dings in my 2 stroke pipe as I am getting ready for the ice racing season. I filled it up with water, got the air out, then plugged the ends. After a day in my freezer I pulled it out and found most of the dings were pushed out but the pipe burst at a seam like I was afraid of. I'm sure I can re-weld the seam but just wanted people to know what can happen. Having a spare pipe is always a good idea. Happy New Year.

I never heard of the water/freezer method, thanks for the heads up. Where do you have ice to ride? I live way north of you and the small lake we ride on isn't freezing up like most years. We usually would have been on the ice a week or so ago.

The smaller ponds are starting to freeze now around Maybrook, NY and West Milford, NJ but today it's warming up. We race at Lake George during the winter carnival and our club is putting on races every sunday if possible in Fallsburg NY at the town park. Next week will be in the teens here in north Jersey but we're still a few weeks away from riding. We have a great little hideaway pond up in the mouintain that freezes early as the sun never hits it and have ridden there in years past before XMas. You're way up there in NY, won't be long for you guys.

That freezing method only works for 4 stroke pipes but it does work. Usually takes a couple different freezings

Freezing works with 2 stroke pipes as well. Just don't plug the ends. Leave the ends open so there is room for some expansion. You might have to freeze it a few times to get the larger dents out. I have used it multiple times with good results.

Interesting. I just know of the block the ends, apply air pressure (be careful!) and then heat. I do not think I will try the freeze method, but who knows.

I froze it twice without plugs with no results. Years ago I used air pressure and my torch to pull dents out untill I nearly blew my head off and had to chase my dog down the road after the explosion. No lie. Never plug a pipe, add air pressure, then heat unless you get all of the 2 stroke oil and gas out of the pipe. I'll never heat a pipe again.

I blow my pipes out all the time. Always burn them out first ! I did put a 2" circular hole in the shop wall when I had to blow out a melted in place plug. Took about 90 psi and I crapped myself even though I knew it was coming. Took about 2 hours to get the shop cat out of the crawl space.

About 25 years ago on one of my "starter" pipe repairs I put about 50 lbs in the pipe and started to heat the dings. Pretty soon the plug blew out, hit me glancing off my forehead and continued up to dent the ceiling in my shop. I soon learned to solder the plugs in, as I am a master plumber, but found I wasn't a master pipe fixer. Now I''ll just bring them to Town and Country Cycle and have em blow them out. I don't want anybody trying this like I did and getting hurt or going deaf, or losing their gun shy dog.

A member in our club tried to get his dents out with the air/heat method. One of the end caps flew out hit him in the nose and head. He looked like a horned head monster for a while. I won't try that now. When mine gets dented I'm gonna just get a new one or buy the new Ossa's LOL!

PS, Always stand to the side of the pipe.

A was burning out a 15 year old KDX200 pipe this week. It was so full of spooge and carbon that I had to shut it down and start over 4 times and the pipe still melted in 3 spots from the heat of the carbon burning. You just get it started from one end then feed it O2 until it burns to the other end. I was burning out an old G-1 yamaha golf cart muffler and it was so full of crap that it got started and I couldn't get it out and ended up with a pool of metal, a couple of pieces of solid metal and a bunch of glass in the gravel. Took about an hour to finally go out.

We used to freeze gas tanks back in the day when dirt bike tanks where metal and you bent them all the time. It was easier because the metal back then was actual metal. Not this tin pot crap they use nowadays.

I guess in a perfect world a guy would want to use a high pressure inert gas(ie no oxygen present)....then you can heat it up all you want without fear......
But I have gotten away with it with no trouble for years.....the trick is how you plug the inlet....

I use a frost plug..tap it in place at the inlet and secure it with two MO FO vise grips......then I manually pressure it up at the stinger with a rubber tipped blow gun...

oh yes point the damm thing away from you just in case.....dont want to be winning any Darwin awards

LOL it's the pro's vs the joe's. Sometimes the joe's get stuff flying out and back at them. It's one of those don't try this at home things.

I have had decent luck with freezing 2 stroke pipes without plugging the ends. But we quickly found out that big dents have a memory, and as soon as you touch the pipe again (crash) it returns to the previous mangled condition. After freezing you need to heat up the pipe to keep that from happening.

Later,

I took a massive dent out of my stock pipe with the air and heat method but I kept a pressure gage on the pipe and didn't let it get over 20psi. I like John01 idea of buying an Ossa better.

Selling the pipe and silencer from my 09 WR250. Brand new take offs. Looking for $150 for the pair.

If that helps. I am an ECEA guy.