125-200cc DIY dented pipe repair

After having a nasty crash a few weeks ago and breaking five ribs and also denting my new fatty I decided since I am doing much better I would spread the cheer and get my WR125 back in shape.
This was my first attempt at dent removal and since it worked so well I thought a little DIY thread would help other fellow Husky riders fix those dented pipes!

Things you need:
All parts were bought at the local hardware/auto parts store for under $15!

to get started you will need freeze plugs (1)1 1/2" & (1) 1"
You will also need (1) threaded air stem from the auto parts store.

By idacurt at 2012-07-18

Take the air stem apart and use just the main shaft and the nut

By idacurt at 2012-07-18

Take the 1 1/2" freeze plug apart and keep the rubber plug and the washers.You will need to trim the rubber plug so that you will be able to thread the nut on the air stem.also drill out the washers/plug to accept the wider diameter air stem.

By idacurt at 2012-07-18


By idacurt at 2012-07-18


By idacurt at 2012-07-18

That takes care of all the hard work!
The 1" plug will have to be slightly trimmed to fit the small end of the pipe

Word of caution!!
Clean all oil from the ends of the pipe before inserting plugs also
Safety wire both plugs to the pipe and NEVER EVER get in front of either end after heat is applied.How do I know this??? well my first plug with air stem went into orbit never to be found after a few minutes of heating,scared the heck out of me and the dogs!

When plugs are in,tightened and safety wired, add 30lbs of air and begin to apply heat to dent and adjacent area until pipe just starts to turn red,you should begin to start seeing the dent come out. I used a hand torch with Map gas(burns hot)

Ten minutes or so is all it took to pull the dent out!


By idacurt at 2012-07-18


By idacurt at 2012-07-18

WOW! where did that dent go?


By idacurt at 2012-07-18

Here is the pipe back on the bike,everyone is safe and happy!
Now I just need to get a pipe guard and more rib protection.
I'm sure I may have left out some details,so please ask questions.


By idacurt at 2012-07-18

Very good write up and great advice on the safty wire. A friend of mine got hit square in his nose when a plug flew out of his ! Thanks for the write up and with great pics. too.

I lost a plug too, kinda gets your attention
Nice write up

My FIL was standing infront of that plug 5 minutes earlier and I said "please don't stand there" when it let lose it sounded like a gun blast and the plug left the yard in a blur,have no idea where it went? On the next attempt the FIL was standing ten feet behind me.

I've been working on my Gnarly pipe trying to get a huge dent out of the left side of the pipe. Cut a large avacado in half, and that's what it looked like. I'm sure I just don't have enough heat cause it's taking FOREVER and it's still has some still to come out. Plus the tight curve probably isn't helping. I'm using an acetelyne torch tomorrow for mass heat. I know not to go crazy on the spot. I hope it looks like the pic above when it's done.

A friend of mine used this method to attempt a dent repair on his pipe and did not fair too well, I cautioned him on not using too much air pressure and heat. Apparently the beer goggles were on and he applied too much of both, he showed me the pipe after his attempt and the dent was still there along with a gaping wound where the pipe melted and blew out! He almost burned his garage down he said when the pipe let go and hot molten metal shot into the christmas decorations in his garage!. He doesn't repair his own pipes any-more since the volcano erupted and I think we are all a little safer for it! I have used this method and had success,the gnarly pipes are a thicker gauge steel and will require more heat ( I use oxy-acetylene) just be patient and go easy on the air pressure! Nice write-up Idacurt!.

Couple of things I always do is burn the spooge,etc. out of the pipe first. If you get it hot enough it could go ballistic unless you use some kind of inert gas to fill it. I also use 50 PSI of pressure as it makes getting the sharp dents and edges better. Using an acetylene torch is best if you have one as you can use a finer tip and really get precise with your repair. The cutting torch makes burning out a snap.

+1 and make sure you are in a well ventilated area and tell your neighbours that the house is not on fire as cleaning spooge caused the fire department to rock up to my house once...at least l know l have concerned neighbours

All went well with the acetylene torch! That dent popped right out in minutes!! All that's left is a little ripple due to the shape of the original dent. It's minor so I'm pleased. I melted the rubber coupling clamped to the pipe which holds the schrader valve. I got a little too close to it trying to remove a pinched spot next to it. No biggy. It didn't blow up. It just released all the air. Hopefully now the gnarly will do it's job.

Great post and helpful replies to boot!

Here's the result of my work on the Gnarly pipe. That dent went all the way down to the bottom of the dark spot. It was big.

Nice job!

Hi, sorry to bring up an old thread...I was wondering if I could use a smaller blow torch to heat up the dent. the little spray-can-sized ones that usually goes into a camping/portable stove.

sth like this:


Thanks in advance!

probably but your best bet is oxysettaline, i use a mapp blowtortch from plumbing, i use 50 psi and make sure my seals are tight i have a clamp the pipe type that have a metal plate over and collars that pinch to the pipe, no way these are comming off.

Ah ok...tks for the reply! will have to browse around a couple of hardware shops for sth that specific.
I hope my pipe will never need to be dent-repaired but it's always good to prepare

I use mapp gas as well, I find I need alot of psi to push out the dents. I don't think it gets hot enough at 30-40 psi, I have to double it nearly.

Starting to think oxy acetaline would be safer in not needing to bump up the pressure so much. Don't know how you guys get anywhere with mapp, I've tried everything it just doesn't seem to be enough heat even for the stock pipe.

i work from just beyond the dent so even before its started to ding and work in circular motions an gradually get to the center, whole process for major dent takes 7-12 mins depending on size, if you have any pin hole leaks the pressure is nowhere near sufficient weld your pipe without pressure in to seal any pinholes up. that may be your problem aviduser.
also i dont have a roaring flame thats just a waste of gass i have it s o the cone is about 1inch long and keep the tip of the cone right on the point you need to heat.

I've recently (like 8mth ago ), bought a proper clamp system to plug the pipe and have used the following:
Propane : Great for shallow dents @ 30/40 psi but cools too quickly if the dent is wide or you'll have to bump up the psi to 70/80 psi whilst trying to maintain heat...danger Will Robinson.
MAPP: Great for wide shallow and some deeper dents that aren't creased as it can maintain more heat but again, you maybe have to go as high as 70/80 psi whilst keeping an eye of the dent and maintain heat...Danger Danger.
Oxy : Simply can't beat it, can heat a greater surface whilst feeding in air pressure enough to noticeably pop the dent out slowly, have yet to put in no more than 30psi using an oxy.

With an Oxy, l pump the pipe to 20psi cold and then work on the dent, shallow dents pop up in less than 5 mins, creased dents tends to need more heat and a little bit more pressure but please be VERY VERY careful with the psi level as you can quickly burst the dent you are working on if you've applied too much pressure and heat - have a gauge/tyre inflator attached so that you can monitor the pressure as well as quickly drop the pressure.