ADVrider

Go Back   ADVrider > Bikes > Thumpers
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 06-06-2008, 09:44 PM   #1
gaspipe OP
Wandering Soul
 
gaspipe's Avatar
 
Joined: Jul 2004
Location: Pickwick Lake, Tennessippi
Oddometer: 11,352
Can a 550cc two stroker be a thumper?



Feels thumperish, pulls like a John Deere. My 1995 KTM 550MXC has been laid up for a while. The 92.25mm piston, made by Mahle, is no longer made, and KTM has given up on 'em.

These old bikes are really very cool - huge torque and HP, with reasonable handling, even by today's standards for fast trail biking. I modified this bike with an Emig triple clamp for an LC4, late model brakes, and a set of WP4860 forks from an '05 SX (adjustable preload...). On went some late model Excel rims, 21/19, and I had a rip snortin' 60+HP fun ride.



Unfortunately, everything wears out eventually I blew the ignition side crank seal last Summer, and parked it. Over the winter, I broke the top end apart. Inspecting the gizzards revealed that the piston had a few cracks in it.

Looking for a piston, I quickly found out that these things are no longer available. My buddy Backdrifter turned me onto a piston - so the beast shall live again.

The Holy Grail of big bore 2 stroke KTM pistons...



I have a plate, so I might even make it street legal now.
__________________
gaspipe [the original]

Hair of the dog....

gaspipe screwed with this post 06-06-2008 at 10:56 PM
gaspipe is offline   Reply With Quote
Old 06-06-2008, 09:59 PM   #2
chickenstrips
Adventurer
 
Joined: May 2008
Location: Fullerton, CA
Oddometer: 11
Send the new piston to wiseco and have some made?
chickenstrips is offline   Reply With Quote
Old 06-06-2008, 10:01 PM   #3
BigM
Hello :-)
 
Joined: Jan 2007
Location: Adelaide, Australia
Oddometer: 766
whats the weight of that thing? (the bike not the piston)?
__________________
KTM 2006 625 SXC
Leo Vince X3 Pipe, Scotts Steering Dampner, Woody's Rear Wheel + Cush Hub, Race Tech Gold Suspension, 18L Tank, Bark busters, Trail Tech SCMR16 HID Helmet Mount, Comfort Seat, Bark Busters, Stealth Sproket, Trail Tech X2, Michelin Desert

Cedo Nulli
BigM is offline   Reply With Quote
Old 06-06-2008, 10:05 PM   #4
gaspipe OP
Wandering Soul
 
gaspipe's Avatar
 
Joined: Jul 2004
Location: Pickwick Lake, Tennessippi
Oddometer: 11,352
Quote:
Originally Posted by chickenstrips
Send the new piston to wiseco and have some made?
Very, very expensive. The day is coming where this will have to be done, or these old bikes will just die off. I figure if I layed out the $10k to run off 50 or so of them, I'd probably get my money back - the question is how long would it take...?

I guess it's just a case of a low production machine, now over 10 years old.
__________________
gaspipe [the original]

Hair of the dog....
gaspipe is offline   Reply With Quote
Old 06-06-2008, 10:06 PM   #5
gaspipe OP
Wandering Soul
 
gaspipe's Avatar
 
Joined: Jul 2004
Location: Pickwick Lake, Tennessippi
Oddometer: 11,352
Quote:
Originally Posted by BigM
whats the weight of that thing? (the bike not the piston)?
Around 230lbs.
__________________
gaspipe [the original]

Hair of the dog....
gaspipe is offline   Reply With Quote
Old 06-06-2008, 10:25 PM   #6
GodSilla
I did that.
 
GodSilla's Avatar
 
Joined: Sep 2006
Location: Downtown S.E. NSW
Oddometer: 7,826
I suppose the bike meets the "one cylinder" bit.
But a thumper is meant to "thump", same as Ducati's "boom" and "thunder".
I suspect this magnificent beast goes "ring" and "ding" and "braaaap".
Do we need a poll?

Still, I'd vote for it. Old ain't necessarily slow or bad, and can be quite "wow!" like this one. Cheers.
GodSilla is offline   Reply With Quote
Old 06-06-2008, 10:42 PM   #7
Bucho
Beastly Adventurer
 
Joined: Dec 2006
Location: Maryland
Oddometer: 1,983
It is a single.

Huge twostrokes are badass and you can call it whatever you want, as long as you can ride it.
Bucho is offline   Reply With Quote
Old 06-06-2008, 11:19 PM   #8
Pro_Marinero
Carbon Sasquatch
 
Pro_Marinero's Avatar
 
Joined: Feb 2005
Location: Ellensburg, WA
Oddometer: 2,090
>500 cc two-strokes are a whole different breed. Yes, they thump, and they pull like tractors. It may not sound like a thump, but it's there.

They also are probably the most maintenance-free single short of an XR. Even that is probably a stretch, as XR's require a valve adjust from time to time. Big-bore 2t's can stretch a top-end into years if you take care of them.
Pro_Marinero is offline   Reply With Quote
Old 06-07-2008, 04:00 AM   #9
johno
Beastly Adventurer
 
johno's Avatar
 
Joined: Dec 2007
Location: Mount Gambier, South Australia, Australia.
Oddometer: 2,911
They do thump. When you gas it up, and it spits you off the back,
you go thump on the ground.

The only "real" 2 stroke I had was an IT125 Yammy. ported, redone suspension. Great bike.
johno is online now   Reply With Quote
Old 06-07-2008, 07:51 AM   #10
TNC
Candyass Camper
 
TNC's Avatar
 
Joined: Mar 2007
Location: Tejas
Oddometer: 4,629
Dang...550?

Obviously I'm not as up on motorcycles as when I worked at a shop for about 15 years in the 70's and 80's, but I still ride and we even put on a state circuit enduro every year for the last 28 years. I had never heard of this bike. That's a freakin' awesome bigass two-stroke. Yeah, it's a shame that manufacturing issues and corporate logic result in some really good older rides drying up due to lack of parts support. GP...I didn't realize that getting a Wiseco custom piston was that expensive. I thought I recalled...back in the ancient days of my shop employment...that Wiseco would make these one-offs for a surprisingly reasonable price. Pretty darned cool bike. The concept of "Thumper" can definitely cross traditional lines with a bike like this IMO.
Quote:
Originally Posted by gaspipe
Very, very expensive. The day is coming where this will have to be done, or these old bikes will just die off. I figure if I layed out the $10k to run off 50 or so of them, I'd probably get my money back - the question is how long would it take...?

I guess it's just a case of a low production machine, now over 10 years old.
TNC is offline   Reply With Quote
Old 06-07-2008, 07:59 AM   #11
Ruffus
Dirty Old Mudder
 
Ruffus's Avatar
 
Joined: Jan 2006
Location: Fort Erie,Ontario
Oddometer: 4,081
Dammit, posted in the wrong thread

feel free to delete my post LOL
__________________
We spend our lives chipping away at our ignorance :wisdom by Dakez

Friendship is like peeing your pants, everyone can see it, but only you
can feel the true warmth.: wisdom by ??



Reverse Darwinism...he's only alive because he's to stupid to die. : wisdom by AZRamjet

06 Husky TE510

Ruffus screwed with this post 06-07-2008 at 08:05 AM
Ruffus is offline   Reply With Quote
Old 06-07-2008, 08:21 AM   #12
dirtydeeds
I'm alive.
 
dirtydeeds's Avatar
 
Joined: Jul 2004
Location: Calgary, AB, Can
Oddometer: 2,680
Say it aint so.

I might need a piston for mine one day.

Maybe I should find one now...

I love my 550.
__________________
990SMT, 640A, TXC450, TE510, ATC350X, ATC200ES, 550MXC, BW200. Need more space in garage.
dirtydeeds is offline   Reply With Quote
Old 06-07-2008, 01:59 PM   #13
gaspipe OP
Wandering Soul
 
gaspipe's Avatar
 
Joined: Jul 2004
Location: Pickwick Lake, Tennessippi
Oddometer: 11,352
Quote:
Originally Posted by dirtydeeds
Say it aint so.

I might need a piston for mine one day.

Maybe I should find one now...

I love my 550.
KTM says no more 550 pistons - all that's left is what's on parts shelves at the dealerships KTM's asking price was over $400!!!!!!

I hope Wiseco or some other manufacturer will start making them.

At least they seem to last - my original one made it 12 years before it cracked, and it was still running fine. I only found out when I tore it down to replace the crank seals and water pump guts.

The 440 uses the same piston as the 500, and those are still available. Only the 550's seem to have been dropped.
__________________
gaspipe [the original]

Hair of the dog....
gaspipe is offline   Reply With Quote
Old 06-08-2008, 05:38 PM   #14
dirtydeeds
I'm alive.
 
dirtydeeds's Avatar
 
Joined: Jul 2004
Location: Calgary, AB, Can
Oddometer: 2,680
Quote:
Originally Posted by gaspipe
KTM says no more 550 pistons - all that's left is what's on parts shelves at the dealerships KTM's asking price was over $400!!!!!!

I hope Wiseco or some other manufacturer will start making them.

At least they seem to last - my original one made it 12 years before it cracked, and it was still running fine. I only found out when I tore it down to replace the crank seals and water pump guts.

The 440 uses the same piston as the 500, and those are still available. Only the 550's seem to have been dropped.
I remember asking wiseco about them. They had nothing. the piston is 102mm in diameter (do i remember correctly?). I found nothing that matched it - except a piston for some old subaru. Damn it.
__________________
990SMT, 640A, TXC450, TE510, ATC350X, ATC200ES, 550MXC, BW200. Need more space in garage.
dirtydeeds is offline   Reply With Quote
Old 06-08-2008, 05:43 PM   #15
gaspipe OP
Wandering Soul
 
gaspipe's Avatar
 
Joined: Jul 2004
Location: Pickwick Lake, Tennessippi
Oddometer: 11,352
Quote:
Originally Posted by dirtydeeds
I remember asking wiseco about them. They had nothing. the piston is 102mm in diameter (do i remember correctly?). I found nothing that matched it - except a piston for some old subaru. Damn it.
They are 92.25mm, but a bit odd where the connecting rod/wrist pin interfaces. I'm sure we could get them to make a run of them, but it won't be cheap. Then again, the stock slug is far from cheap, if you can find one.
__________________
gaspipe [the original]

Hair of the dog....
gaspipe is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 03:16 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2015