Welding on a crank?

[matrox02]

Hi guys, I have an 1990 RMX250 L that is near on impossible to find a replacement crank for does anyone here know if its possible for an engineer to weld on said crank to fill in a flat spot on a crank shaft flywheel shaft and then have them turn it back down to suit the rest of the shafts shape? or would anyone say to leave it as is??

I would post a picture but the picture i have of it at the moment isnt too great and doesnt really show the issue

anyone know otherwise? anyone know of a decent guy who can do the work in auckland too??

[unstuck]

Would a speedy sleeve not work?

[skippa1]

Hi guys, I have an 1990 RMX250 L that is near on impossible to find a replacement crank for does anyone here know if its possible for an engineer to weld on said crank to fill in a flat spot on a crank shaft flywheel shaft and then have them turn it back down to suit the rest of the shafts shape? or would anyone say to leave it as is??

I would post a picture but the picture i have of it at the moment isnt too great and doesnt really show the issue

anyone know otherwise? anyone know of a decent guy who can do the work in auckland too??

Welding on a crank is possible, but not advisable due to heat distortion/alteration of the hardness/brittleness of the metal. It can be successfully done though. Machining likewise. Cost is a whole different ball game. You need engineers that know what they are doing, not think they know what they are doing.

[Akzle]

that sounds entirely possible

[matrox02]

Would a speedy sleeve not work?

From what iv seen of the speedy sleeves no, if you look at the link, the flywheel goes on after part 14, the flywheel is on a tapered shaft

http://www.partzilla.com/parts/search/Suzuki/ATV/1990/RMX250T%20/CRANKSHAFT%20%28MODEL%20L-M-N%29/parts.html

From what i know the speedy sleeve only works on non tapered shafts, though, that may be an idea to make a sleeve to fit? only problem is i would need the woodruf key to be in the right place and the only other problem is that it would weaken the shaft itself

[matrox02]

Welding on a crank is possible, but not advisable due to heat distortion/alteration of the hardness/brittleness of the metal. It can be successfully done though. Machining likewise. Cost is a whole different ball game. You need engineers that know what they are doing, not think they know what they are doing.


yeah.. thats my problem so far, No one ( engineers ) has been able to give me a definite answer, Im thinking maybe I should glob on high temp solder and then just smooth it out just to get the shape and balance back somewhat?? its going to be held in by a flywheel anyways, so i dont think it will just "fall out" or anything?

[skippa1]

yeah.. thats my problem so far, No one ( engineers ) has been able to give me a definite answer, Im thinking maybe I should glob on high temp solder and then just smooth it out just to get the shape and balance back somewhat?? its going to be held in by a flywheel anyways, so i dont think it will just "fall out" or anything?

Whack a good pic up, hard to imagine the extent. There are engineering companies that have the expertise on staff up your way. I may be able to point you in the right direction. Pics first

[Haggis2]

Engine reconditioner?

[matrox02]

Whack a good pic up, hard to imagine the extent. There are engineering companies that have the expertise on staff up your way. I may be able to point you in the right direction. Pics first

cheers, i will do, sadly.. Im at work till 3pm so ill have to try to remember to upload a pic, I though also thought that maybe i should just JB weld the prick and just reshape the jbweld Hmm, I also needa m12 x1.25 die to chase the threads

[AllanB]

Bloke in CHCH welds all types of engine parts old and new. Highly likely he has welded numerous cranks.

[unstuck]

I used knead it steel on a crankshaft on a v6 maxima about a year ago, still going strong. The key way for the crankshaft pulley had broken away on one side, and this seemed like the simplest solution at the time to get the car back to gore. It does some big kms too and no dramas yet.:Punk::Punk:

[jonbuoy]

Don't see why not, cranks get built up with weld for increasing the stroke all the time. Maybe find a performance/ classic car engine reconditioner.

[matrox02]

I used knead it steel on a crankshaft on a v6 maxima about a year ago, still going strong. The key way for the crankshaft pulley had broken away on one side, and this seemed like the simplest solution at the time to get the car back to gore. It does some big kms too and no dramas yet.:Punk::Punk:

That right there i think is my ticket to Success, Ill buy a tube of that and order my seals and bearings and gaskets sooner than i thought!

[DrunkenMistake]

get it metal sprayed and turned back to whatever it needs to be?

[Grumph]

metal spraying gets the shaft too hot - distortion is what you want to avoid.

From the sound of things it's on the taper - broken out the keyway ?

The crank will have to be split as once it's built up it needs machining between centers. Personally, I'd use bronze. Once the taper is lapped, the key is only to ensure correct assembly and doesn't actually hold anything.

[matrox02]

metal spraying gets the shaft too hot - distortion is what you want to avoid.

From the sound of things it's on the taper - broken out the keyway ?

The crank will have to be split as once it's built up it needs machining between centers. Personally, I'd use bronze. Once the taper is lapped, the key is only to ensure correct assembly and doesn't actually hold anything.

No its not the key thats broken, when i cut the old flywheel off i cut a bit deep and cut into the shaft, the key is fine otherwise

[Woodman]

Machine a new keyway 180 degrees from the original and adjust timing etc accordingly

[matrox02]

Machine a new keyway 180 degrees from the original and adjust timing etc accordingly

Its NOT Key way :S

[matrox02]

OK so i managed to get pictures, Pic 1&2

291957

291958

I just cleaned it with methylated spirits, Ill try the knead it steel now

[george formby]

If you can get the relevant part numbers try this outfit. Got all the bits for my DT crank offen em. JP-Parts (http://www.jp-parts.com/?gclid=CKDw74rp0K0CFcVKpgodAkafnQ)

[AllanB]

Bit of JB weld and she'll be all good to sell ...........

I don't see any reason why a skilled welder watching the temps could not build that up for you so a skilled machinist could turn it down. Few bucks though .......

[matrox02]

If you can get the relevant part numbers try this outfit. Got all the bits for my DT crank offen em. JP-Parts (http://www.jp-parts.com/?gclid=CKDw74rp0K0CFcVKpgodAkafnQ)


Awesome, Ill flick them a query, I finished allying that steel stuff, Ill see how that goes

[unstuck]

I made a gear lever out of minute mend once, lasted a couple of good trail rides.:Punk::Punk:

[skippa1]

OK so i managed to get pictures, Pic 1&2



I just cleaned it with methylated spirits, Ill try the knead it steel now

You sir, are a butcher with a hacksaw

[matrox02]

You sir, are a butcher with a hacksaw

though.. it was an angle grinder, and yes, its nasty

[2smokes]

Before you do anything dodgy, it CAN be fixed. Take it to a good engine reconditioner. They will build it up and grind it back. Same way they repair and re-grind race/vintage stuff. Talk to an old tradesman.

[hayd3n]

i repaired my clutch lever with that metal putty stuff its still good as

[Woodman]

Before you do anything dodgy, it CAN be fixed. Take it to a good engine reconditioner. They will build it up and grind it back. Same way they repair and re-grind race/vintage stuff. Talk to an old tradesman.

Except you cannot grind tapers on a crankshaft grinder.

[Ocean1]

OK so i managed to get pictures, Pic 1&2

It's fukd. Those RMX crank ends are a weak point, I've seen a few bent and battered ones.

Like the thread on the end of that one where someone's pounded the shit out of it trying to get the flywheel off.

Anyone with the experience and gear to fix it is going to charge you more than the price of a new one to do it.

[matrox02]

It's fukd. Those RMX crank ends are a weak point, I've seen a few bent and battered ones.

Like the thread on the end of that one where someone's pounded the shit out of it trying to get the flywheel off.

Anyone with the experience and gear to fix it is going to charge you more than the price of a new one to do it.

hmmm.. well if anyone can source a new one.. then im all ears, because they are simply not made anymore

[scumdog]

OK so i managed to get pictures, Pic 1&2

291957

291958

I just cleaned it with methylated spirits, Ill try the knead it steel now

Grab some J-B Weld and build up the 'bad' area then sand it down finishing with 1200 grit:niceone:.

[gammaguy]

http://www.ebay.com/itm/94-1994-rmx250-rmx-250-crank-shaft-crank-shaft-rod-US-WORLD-SHIPPING-AVAILABLE-/151200627629?pt=Motorcycles_Parts_Accessories&fits=Make%3ASuzuki%7CModel%3ARMX250&hash=item2334427bad&vxp=mtr

[Brian d marge]

A bit far !!! , fk u were pissed as bro !

yes they can be welded up and re machined , DO talk to a vintage repair shop OR an old fart who chain smokes and can find his spectacles

the metal isnt flash on those , but the stresses are right at the root /end of your cut ( there are up and down forces and clockwise anti clockwise and hertzian or where ever you created the stress raiser ,, and you do not want to make that brittle by incorrect temp control or it will shear at the base of the taper ,, not immediately but it will happen

sorry I can give a bit more detail but must take boys to Judo

Stephen

[Kickaha]

PM Swarfie, he's a right clever bastard and will be able to point you in the right direction

[pete-blen]

I wouldn't think twice about welding that...
use a tool post grinder in a lathe to regrind the tapper as
you can set the compound angle to match the crank tapper..

Even though they are out of fashion these days.. I would use a arc welder
Rods.. common old low hydrogen.. Was all we use to use on the TZ crank pins
to stop the cranks going out of true...

remove the cut section to ensure theres no voids in the weld..

really it all pretty easy..

[jonbuoy]

It will be in compression so JB might work but will always be a bodge. You would have to split the crank for welding/braizing. I'm sure any crank that gets welded must distort a little bit, when a machine shop does it they will check/straighten the crank afterwards anyway so not a problem in those cases.

[matrox02]

http://www.ebay.com/itm/94-1994-rmx250-rmx-250-crank-shaft-crank-shaft-rod-US-WORLD-SHIPPING-AVAILABLE-/151200627629?pt=Motorcycles_Parts_Accessories&fits=Make%3ASuzuki%7CModel%3ARMX250&hash=item2334427bad&vxp=mtr


I wish that did fit, only the 89 to 92 l m n models fit, thats a s t 94 and have differant everything,

Otherwise ill see if the knead it steel stuff just falls off or not during the day if not then ill file down to shape and what happens there, if it does fall off ill be on more of a look our for an old boy sitting in the back of an old shop

[Brian d marge]

I wish that did fit, only the 89 to 92 l m n models fit, thats a s t 94 and have differant everything,

Otherwise ill see if the knead it steel stuff just falls off or not during the day if not then ill file down to shape and what happens there, if it does fall off ill be on more of a look our for an old boy sitting in the back of an old shop

The joint is a taper , or an interference fit,

Think of it as yer cock going into a tight young virgin , shes going clamp down on your tool good and tight,

now forty years later ( or in this case half a ton of JB weld , with lesser mechanical properties ) your cock aint as firm and that tight young hole wouldnt be stretched as much , and your cock aint clamped as much as it was back in the day ,

So after a while it may slip out , or in this case you will find it hard to keep your flywheel from coming loose ( it will just shear the key and spin )

you might be in luck , as it is lightly loaded and wouldnt need much of a taper to hold it , but by the looks of that photo my guess its touch and go

Im not familiar with Suzuki pt numbers , but many of hondas parts are shared across quite a few models and even then all you want is that shaft ! are you sure nothing else can be found that will work?

Stephen

[matrox02]

The joint is a taper , or an interference fit,

Think of it as yer cock going into a tight young virgin , shes going clamp down on your tool good and tight,

now forty years later ( or in this case half a ton of JB weld , with lesser mechanical properties ) your cock aint as firm and that tight young hole wouldnt be stretched as much , and your cock aint clamped as much as it was back in the day ,

So after a while it may slip out , or in this case you will find it hard to keep your flywheel from coming loose ( it will just shear the key and spin )

you might be in luck , as it is lightly loaded and wouldnt need much of a taper to hold it , but by the looks of that photo my guess its touch and go

Im not familiar with Suzuki pt numbers , but many of hondas parts are shared across quite a few models and even then all you want is that shaft ! are you sure nothing else can be found that will work?

Stephen


yeah sadly, not with out changing alot more than just the bearings and seals, even the RM250 motors are different in many ways, seams as thought he only truely cross compatible parts are the barrels and heads

[matrox02]

So i found a machinist/metal refurbisher who is willing to do the job, it will however require that i have a flywheel to do test fitting, he says that metal spraying and then balancing the shaft is what he will do and he will do it for 200 cash so i think ill do that, just need to find a Flywheel for my bike now

[matrox02]

So, I needed a flywheel and nut to get the crank repaired, I call Suzuki and tell them i need a full stator assembly and a new flywheel/rotor, they get back to me with a quote of 780 bucks for the stator ( Must be gold plated! ) and the Rotor at just shy of 500! ( must be gold plated too! ) Im glad Ebay exists though as a New after market Fly wheel stator assembly and coil-cdi and a bunch of other things for 800 ndz all up shipped from America and thats including Duty costs.. I can only say that im stoked!, next is Bearings/seals and gaskets and rear shock rebuild and im sorted!

[george formby]

Did you go for a quote from JP-parts?

[speights_bud]

If it wasnt for the price I would have recommended Laser welding it up, we send our parts from Napier to Auckland to have a Chap up there do it, lots of our stuff is very finicky (toolmaking boo boos) but the heat put into the crank would be very minimal.

[matrox02]

Did you go for a quote from JP-parts?

Yeah I emailed them with their responce being " Not made anymore, cannot help" so.. maybe for other parts.. but not the webs :S

[matrox02]

If it wasnt for the price I would have recommended Laser welding it up, we send our parts from Napier to Auckland to have a Chap up there do it, lots of our stuff is very finicky (toolmaking boo boos) but the heat put into the crank would be very minimal.

what sort of prices are they? Im having my crank fixed up for 200 cash thats metal sprayed and machined ( I hope they dont fill the key way in! )

[speights_bud]

what sort of prices are they? Im having my crank fixed up for 200 cash thats metal sprayed and machined ( I hope they dont fill the key way in! )

Probably about 200 or a little more just for the welding

[Banditbandit]

Welding on a crank is possible, but not advisable due to heat distortion/alteration of the hardness/brittleness of the metal. It can be successfully done though. Machining likewise. Cost is a whole different ball game. You need engineers that know what they are doing, not think they know what they are doing.

wot he said .. seen it done ... by experts ...

[matrox02]

So i finally got my new after market stator regulator and flywheel, and im Stoked with the quality of it! and i got annoyed that allll the bike shops local to me where busy or would charge a fortune to seperate the webs, so i bought a press and have separated it myself :)

293507
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293509
293510
the press was only 200 bucks brand new, I wont complain with that, My work shop(backyard one ) is ever expanding, but i never thought to get one of these haha

[Yamahardman]

The next trick, pressing back together right.
I was always told to square a nick, on the end of the crank throws, heat the crank throws, re square the line and press quickly.
Seems to work pretty well.

[matrox02]

The next trick, pressing back together right.
I was always told to square a nick, on the end of the crank throws, heat the crank throws, re square the line and press quickly.
Seems to work pretty well.

Not quite the next trick, I first have to see why my flywheel isnt fitting right, it sits around 6mm below the threads so will never be able to be tightened/locked into place, so they may have sent me the wrong kit, which will be another annoying months wait