Topics

1

Tech Talk / Shift problems YZ125

« on: October 31, 2015, 01:40:32 pm »

Not a VMX, but my sons 2009.

It won't shift sometimes under load into 5th and 6th. I've pulled the side off and clutch out, gone through all gears and it seems to hang up between 5,6 sometimes and takes a bit of manipulation to get into gear.

Before I pull the shift pawl, stopper and drum out, has anyone got any thoughts, what to look for?

I can see into the box and there is no signs of wear.

2

Tech Talk / Radiator repairs

« on: January 31, 2015, 09:13:20 am »

Can anyone recommend a decent bike friendly radiator repairer in brisbane?

My left cr250 radiator is a slightly bent out of shape, it's not leaking or anything, just want to get it tidied up a little.

3

Tech Talk / Gearbox bearings

« on: December 28, 2014, 10:31:49 pm »

I've just started putting my 96 cr250 engine back together and one of the gear box bearings on the right case is loose, and hasn't developed an interference fit. It's the bearing for the main shaft.

There's no signs of damage or wear on the bearing seat and I'm using OEM bearings, I can't find any reference in my clymer manual, is it possible it's meant to be this way?

If not, can anyone recommend a fix?

4

Tech Talk / Brisbane engine balancing

« on: November 14, 2014, 12:17:29 am »

Anyone had any experience with this fella? I spoke with him, he's based at capalaba and does dynamic balancing of bike cranks?

Seems the same process as franks cranks, and being based in Brisbane is convenient for me.

Only thing that concerned me was he said depending on the crank sometimes he has to split them and has someone like serco reassemble, not sure how that would work?

5

Tech Talk / Ultrasonic cleaner Brisbane

« on: September 29, 2014, 10:01:26 am »

Anyone know of someone who does this process for cash? I need a couple of cr250 cases done, they've been bead blasted already, and really just need to get them cleaned within an inch of there life ready for reassembly.

6

Tech Talk / Brake rebuild problems

« on: July 19, 2014, 07:16:58 pm »

So I've rebuild the caliper and Master cylinder on my 96 cr 250 and can't get any feel what so ever. Have bled the normal way and reverse bled with a syringe. I've even pulled the master cylinder apart again thinking that I might have damaged the seals when fitting to the piston but they look fine.

I got no more bubbles when feeding the fluid in from the bottom with a syringe, but after closing the bleed nipple can get a small bubble or 2 in the bottom of the MC when pumping the leaver.

Is my MC buggered? Any ideas?

I'm using a new Hel braided line as well, if that helps.

7

Tech Talk / zinc platting Brisbane

« on: January 27, 2014, 10:59:39 pm »

Anyone know a zinc platter in Brisbane that will do a small batch on the cheap. I had all the big stuff done by CP platters and wasn't overly happy with the finish, I want to get a few redone and about 30 small bolts that I forgot.

8

Tech Talk / First bottom end Rebuild

« on: October 06, 2013, 11:06:50 pm »

So I've been buying and selling my house for the last 6+ months and haven't even touched my CR250 resto, until this weekend.

After taking firko's advice I decided to give it a go for myself and bought the right tools etc. The good news is the cases are apart and I didn't cock anything up yet.

I need some guidance on a couple of things though, hoping you blokes can help0:

- Stud removal, head and cases. I want to get these zinc plated before reassembling. Is the 2 x nut method the best option for removal, or can I expect the stuff the studs and a fair bit of suffering.

- I want to zinc plate the case bolts, firko suggested getting all new bolts, whats the theory behind this? And will a standard zinc plate finish have any issue going into the Aluminium case, corrosion etc?

- I need to remove the bearings from the gear box and the main bearings, before I can aquablast. Some are easy to remove, others are blind, any tips for removing these without a bearing remover? Put the whole case in the oven at 100-150c and watch them fall out?

- Anyone see any problem using the gear box bearings again, assuming I can remove them gently? These feel tight and look good, I don't want to waste money for the sake of it, Main bearings and all seals will be replaced.

Any help appreciated.
 

9

Tech Talk / Head Stem Bearing

« on: January 19, 2013, 08:05:00 pm »

-So I am trying to fit the bearing on the bottom of my steering stem, CR250 1996.

Found a piece of PVC and it was perfect diameter, put the stem in the freezer for a couple hours, wacking the bearing with PVC for a good 5-10mins and it is still a good 20mm from seating.

Any suggestions?

Obviously a press is the go, anyone in Brisbane got one and want to earn some beer money?

Doesn't surpise me actually that it is so tight, the original bearing I cut off with a dremel and it took some work to remove, when I finally got through it gave a loud crack from the pressure.

10

Tech Talk / Mechanic Brisbane

« on: December 27, 2012, 10:08:54 pm »

Anyone know of a good mechanic in the Brisbane area that does a bit of cash work on the side? I'm not a rich man, so any savings help.

In a month or 2, I will have my 96 CR250 rebuild almost to rolling stage and at that time I will start thinking about the motor and what to do with it.

Crank play seems O.K, the cylinder looks good, need to have some measurements done to be sure.

I've toyed with the idea of a new top end only, to sending the crank to the US to have it balanced and lightened, need some solid advice/guidence I suppose.

I know of a good mechanic, but would need to drop the engine off at his shop and collect it finished using mainly the aftermarket parts they supply. I want to use OEM where possible, supply my own parts and maybe modify a few things along the way, so it could take a few months to build.

Was tempted to do it myself, but haven't done a bottom end before, so am a bit nervous and by the time I buy case spliters etc, it might not be worth the pain and suffering.

Any contacts appreciated, Cheers Jim

11

Tech Talk / Aqua/Vapour blasting Brisbane

« on: November 17, 2012, 01:44:35 pm »

G'Day, I'm new to the forum, have been reading plenty of old posts and there is a few nice builds on here.

I'm in the process of building a 96 CR250, which I know is far from VMX but is a good canvas for my first rebuild, I plan on doing more.

Anyway I know there are is a fella in Sydney doing aqua/vapour blasting, but was hoping someone could point me in the direction of a reasonably priced blaster in Brisbane?

I need things like Brake calipers, cylinder, shock body etc done, and am looking for the raw cast Aluminium look. Would prefer Local so I can deliver and collect, will probably need 2 batches done over the next 6 months.

Thanks Jim