Messages

1

Tech Talk / Re: Shift problems YZ125

« on: November 01, 2015, 09:01:49 am »

So what your saying, is I'm likely going to have to split the cases.

I had another look last night and it will hang up a little in the lower gears.

Before I go the route of splitting cases, I'm going to try giving the shift pawl a clean and the shift stopper. If I can get it to shift a little easier, I'll replace the stopper and give it a test ride.

Apparently the 05-06 models had a known problem with their shift stoppers, causing the same symptoms, except eventually the roller would shit themselves totally.

2

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.

3

Tech Talk / Re: Plastic Tank Restorer in Aust

« on: June 28, 2015, 10:15:13 pm »

If you do find someone, I'd be keen to know.

I'd like to find someone who can make white tanks, white again, rather than dull yellow.

4

Tech Talk / Re: 1994 CR125 FOOTPEGS

« on: March 21, 2015, 09:12:01 pm »

Titanium yz 125 foot pegs fit perfect on my 96 cr 250, I'm guessing the 125 of that era would have the same mounts.

5

Tech Talk / Re: Radiator repairs

« on: January 31, 2015, 12:38:34 pm »

I considered these, I've heard a few mixed reports about hole alignment is all. Your right though they are cheap for what you get.

The bikes a 96.

6

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.

7

Tech Talk / Re: Gearbox bearings

« on: December 30, 2014, 10:21:54 pm »

Thanks for all the advice, I've convinced myself that the loctite 620 is the most practical answer and grabbed a bottle today. I wouldn't go that option if it was a main bearing etc, and given that the seat is only a fly shit worn, she'll be right.

8

Tech Talk / Re: Gearbox bearings

« on: December 30, 2014, 01:27:43 pm »

Photos attached, the culprit is the top right in the first photo. I got I wrong too, the gear box needs to be assembled from this side of the case, so the bearing will stay put. Opinions please? Loctite and be done with it? The bearing seat is in good condition as you can see by the other photo.

9

Tech Talk / Re: Gearbox bearings

« on: December 29, 2014, 08:43:59 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?

It is Quite possible that this is a design feature, where the bearing is designed to re-align itself as the cases expand and  contract with temperature change. (Cold engine-Hot engine) The other end of the shaft/bearing assembly is often securely mounted with a retaining plate on the track and a strong circlip on the shaft. Other than that if the bearing is a bit too loose loctite bearing mount does the trick. cheers pancho.

I'm thinking this could be a reasonable explanation, the only problem I can see is on assembly of the bottom end the, gear box is assembled from the left side case and holding the said bearing in place will be a PITA.

I Know some of the bearings fell straight out of the case when heated on disassembly, should have paid more attention at the time though, to which ones. Admittedly I did take the engine apart almost a year ago now, so that's a bit of challenge in itself.

10

Tech Talk / Re: Gearbox bearings

« on: December 29, 2014, 08:36:53 pm »

Hey Jim, here is a great link to an engine rebuild for the 92-01 CR engine.  Perhaps you can rip one of the pics out of it, highlight what bearing it is and post it up. Someone on here is bound to know more about it.  Green loctite, retainers,  OEM bearing etc, im sure there is a simple solution..  anyway, check out this link as im sure it will help in your rebuild..
http://www.allthingsmoto.com/forums/f-14/92-01-honda-cr250-engine-build-tutorial-64413/
Cheers,
Alex

Yeah mate, I've been all over these threads on ATM, the bloke who wrote them is a wizz with these Cr250 engines. I tried contacting him to get is opinion, but haven't heard anything back yet. Will get some photos posted and see what you more experienced blokes reckon.

Thanks Jim.

11

Tech Talk / Re: Gearbox bearings

« on: December 29, 2014, 01:09:04 am »

It's weird because all other bearing are pretty snug, even with heating the case and freezing the bearings, they all pretty much needed some persuasion, except the ones with retainers. So the cases are pretty good condition generally and I don't think the motor has done much work for its age.

I be interested to know how well the loctite works for the long term though, it looks pretty good and I'm only talking a fly shit of interference required.

12

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?

13

Tech Talk / Re: Case bearings dropping out easily!

« on: December 01, 2014, 11:28:31 pm »

What's the best way to tighten up the tolerance on engine mount holes? I've read that they can be a major cause of vibration, any ideas for shimming them?

Was reading an article on Eddie Warren recently and Apparently he used to shim his engine mounts to reduce vibration, not sure how though.

14

Tech Talk / Re: Zinc plating - Qld

« on: November 24, 2014, 08:33:41 pm »

Hi Col,

Are you down this neck of the woods now? I've used CP platers and they are too commercial, the finish was terrible. I had GC Electroplating redo them and the finish wash much better, although not perfect. Price was fair and turn around about a week.

If I had my time over I would have prepped my bolts with my bead blaster first, rather than a wire brush. They say you don't have to, but I reckon the finish is better when prepped properly.

I've been meaning to ask you what colour silver spray paint did you use to paint your r/h side case cover on the 96? I've got a new OEM clutch cover I'm trying to match.

Cheers Jim

15

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?