Swingarm problems

[YZ250H]

Hi guys, after some help (again)
Tracked down the new swingarm bearings and before I took the arm to the sandblasters I tried fitting them.  Turns out they slide into the tube way too easily, so I'm guessing the tube on the swingarm is flogged out from lack of maintenance  .

Question is what to do with it ??  The previous owner  has had brass bushes turned up.  Should I just put these back in and pretend it's all good or try to shim the tube or have new ones welded in.  I can probably pick up another swingarm off an IT465 to canabalise.  Do you think I should bother?.  Will the brass bushes affect handling ?

Looks like I got more than I bargained for when I bought this HOS.  Any and all discussion / suggestions greatly appreciated.  TIA for your help.
Cheers

[lms6201]

u may be trying to fit later (approx. 83 on ) bearings , there is 1mm diff , i have a 490 and i guess the bearings will be the same as 250 ,  465 and j 490 use 29mm od , k 490 and on use 28mm od , all balls have a kit 

[YZ250H]

Thanks IMS.  When I get the swingarm back I will put the calipers on it to see what I've got.
Thanks for the tip - could save me a whole world of hurt.

[vandy010]

when you find out what you've got. theres still the option of harrassing your local bearing shop for a larger O.D. bearing.

[lms6201]

best of luck , u,ll get the ones for 83(k ) and on but not the 29mm od  j and back ,u still have to buy the solid bushes from yamaha , why would u bother for about $130 from pro x or all balls ,including the solid bushes , bearings , bushes  (one bearing one bush a side ) thrust sets and seals , u can get a lot of yam bearings at skf ect. but there is a few u can,t like main bearings are the same size but don,t have enough radius to fit the crank

[YZ250H]

Got the swingarm back from the blasters - looks good and will be sweet painted.  However before I put good 2 pac and $22 decals on it I need to get this sorted.  Took a few measurements with the calipers this afternoon.  Inside diameter between 29.2 and 29.48.  Luckily the blasting was cheap.  I'm starting to think it could be something for the dump (the swingarm not the bike )  For all you machinists out there is the variation in the diameter small enough to take a bearing ?

At a bit off a loss as to what to do here - suggestions ??  Try the 29mm ??  Get the tube reamed to 30 and put a 2mm sleave in and use the 28mm kit ??  Bin it and start again ??  Get it reamed to 30mm and put 30mm bearings and bushes in ??  I'm a bit concerned about reaming it as there doesn't seem to be a whole lot of meat left on the tubes.


Luckily I can use the bearing kit from All Balls on the 125H if it all turns pear shaped (one advantage of having a stack of restos  to do ).  I agree with IMS that the all balls kits seem to be the way to go.  For YZ250H the kit was $US49 (from memory)

Looking for the best way forward and open to suggestions 'cause I'm buggered if I know.

[GMC]

I have repaired these before, I cut the tubes off, machine up new ones, weld them in & then get it heat treated back to spec. I would consider this the right way to do it, it is probably the dearest too. Allow around $250.00 to do this.

Your next bet is to try to find another swingarm. Maybe at CD5

The reaming to slightly bigger might be the easiest way, but your right, be wary of how much meat is left. Check with bearing suppliers for a slightly bigger bearing instead of a sleeve

You probably should have sorted this before blasting

[Lozza]

A few pics would help.
Q1.Are the new bearings needle roller?
Q2 If answer yes to Q1, do they have a hardened sleeve in and outside the needles?
Q3 When you measured 29.2 and 29.4 was that in the same spot or do you mean the bore is oval?
Q4 Are the machined bushes a good fit in the swing arm and on the pivot bolt?

[YZ250H]

Yeah GMC - you are right about sorting it before blasting - never mind only cost me $20.  Missed out on a swingarm at CD5 by a matter of minutes on Saturday.  I was going to crash tackle the bloke, but thought it may not be appropriate.

Lozza
A1 - Yes
A2 - Inner hardened steel sleeve - sadly no outer hardened steel sleeve (the root of all the problems)
A3 - 1 Measurent on each tube - obviously I will need to do more
A4 - Yes, a pretty good fit.

I think I'm going to give up and look for another swingarm - refer wanted section.

Thanks for your help guys - great to meet you both at CD5.

[mainline]

There's a guy from Moruya advertising a lot of bike parts in the OZVMX classifieds, I've got a couple of parts off him, it might be worth shooting him an email.

[YZ250H]

Thanks for the Tip mainline - will do.

[490 tez]

instead of throwing it i have in the past machined bronze bushes to suit worn swing arms and you would have to be a very good rider to pick the differance beetween rolers and the bushes to make it even better you can put a grease nipple in this not only lubes but flushes the shit out from a good days ride be carefull it doesent hit on any thing as it goes up and down as well look where the chain goes good luck

[GMC]

A2 - Inner hardened steel sleeve - sadly no outer hardened steel sleeve (the root of all the problems)

Usually the needle rollers have a thin metal case that the needles run in. If the arm is out of round it forces the needle cage out of round.
Don't throw that arm out as you never know how desperate you might get.

[Lozza]

If you can put a grease track internaly in the the bronze bushes will be good for a few years.