Messages

46

Technical / New YZ Project

« on: November 01, 2013, 10:16:19 AM »

Pretty sure my 2001 CR125 had a hot rods in it that held up well to my (extreme) abuse.

47

Technical / Piston/Cylinder diagnosis

« on: November 01, 2013, 02:29:46 AM »

New top end went in last night. Spent like 3 hours trying to figure out the stupid power valve linkage spring but its all good now. Did my first heat cycle this morning, going to work now and and another one this arvo.

On a side note does anyone know if KTM made some changes to the cylinder head centre o-ring from 2011-2013?

THanks again all.

48

Technical / New YZ Project

« on: November 01, 2013, 02:25:28 AM »

Deinitely go a new crank but as for hot rods or wiseco, I've heard more bad things about wiseco. You're the second person on here that has had a hot rods seize in six hours on a honda. Was yours an 85?

49

Technical / KX250 front brake problem

« on: October 28, 2013, 05:22:42 AM »

Most new pads need to be "broken in", this process is usually written on the manufacturer packaging somewhere (that we never read) which could help.

Good thought. Fresh rotors need a little break in too I'm told. Running a KTM means you never have to buy another one 

50

Technical / KX250 front brake problem

« on: October 28, 2013, 12:31:03 AM »

Something on the pads?

I agree...  (I can't believe I'm tying this ) Try Stu's method and let us know what happens... 

Happy day! Don't do it often though unless you really like replacing brake pads

51

Technical / KX250 front brake problem

« on: October 26, 2013, 11:57:20 PM »

Something on the pads?

x2 go somewhere you can ride in a straight line, ride along in first gear and drag the brakes until it gets quite hot. Hopefully that will evaporate whatever is on them. Sometimes if you spray WD-40 on the bike somewhere, it can mist over and settle on the rotors or something like that. I find degreaser is just as bad so if you were washing your axles with that be careful.

52

Technical / Piston/Cylinder diagnosis

« on: October 26, 2013, 11:51:42 PM »

It all looks fine to me, tiny bit of blow bye, but that's to be expected, after 30hrs @8000rpm that piston and rings have traveled along that bore 28800000 times, wear is to be expected.
Drop a new slug in and close it up doctor and get back out on the track...

Definitely. Poor little rings 

Bye bye vertex! I wish KTM would start putting wossner in their production bikes. They run a forged KONIG in their four strokes I believe. I would have thought it would be easier to buy it all from wossner, I think their factory teams run wossner anyway.

While I've got the majority of the bike down, I'll get a one size bigger and one size smaller main and same for the pilot, just gotta find out what they are the cat chewed up the piece of paper I had it all written down on. ****in cats...

53

Technical / Piston/Cylinder diagnosis

« on: October 25, 2013, 11:08:38 PM »

oh yeah....your hands are grubby.

That hurts my feelings... 

54

Technical / Piston/Cylinder diagnosis

« on: October 25, 2013, 10:24:50 AM »

210psi? uh...
Hit the walls with a scotch bright pad, it should clean right up. I'm sure you meant 110psi, so my thought is maybe the rings didn't seat correctly?

Yup my bad 110 lol. 20:1 compression ratio in my 250sx, didn't you hear? I did a diesel conversion 
I think the dealership threw in a fresh set of rings for hte purpose of sale before I got it. Thing is, they failed to mention that and I went right into new-bike-glue-the-throttle-the-****-open mode.

Cheers.

55

Technical / Piston/Cylinder diagnosis

« on: October 25, 2013, 07:59:36 AM »

Did a compression test today, gave me 210 PSI with no air filter, WOT and 10 full kicks. Definitely time for a top end goes I. I bought hte bike from a dealership with a claimed 10 hours on it, I have put on an additional 24 aleast 20 of which are well thrashed hours. I don't trust other people with my motors so I ordered in a full top end from the small end on up with gaskets and will hopefully be here next week. Have to give tomorrows practise a miss though   

What I need though is some other opinions on my cylinder. I'm fairly certain whats shown below is ring blow by from the excessive hours on the rings because I can't feel any change in teh surface and I ran my cylinder bore gauge over it aswell and it gave no different readings. Theres a little bit of ring blowby on the piston aswell, but no score marks to match the cylinder, hence my conclusion.  But I'm still quite new to this game and don't know very much so any opinions are appreciated.

Wash pattern:


General look:


Close ups:




Cylinder:


Cylinder other side:


Thanks in advance for any advice.

56

Technical / New YZ Project

« on: October 24, 2013, 10:05:07 PM »

That's one rough bike to start with....  which will make the build more rewarding. 

I think you'll be happy in the end as '01 is a good year for the yz125....  I know I like mine an awful lot.

'01 is the last year they had a steel frame AND a 6-speed trans....  '02-'04 went to a 5 speed trans and '05 went to aluminum frame.

I also think you'll be happy having it stay a 125...    once you go up in displacement, it loses a lot of its charm.   

Yamaha went to a 5 speeder from 02 onwards? Really? As if the Hondas weren't enough of a failure.

57

Technical / New YZ Project

« on: October 23, 2013, 11:48:58 PM »

Oh dear... Better crank up the pressure washer mate.

58

Technical / New YZ Project

« on: October 21, 2013, 05:43:47 AM »

make a photo bucket account, upload the photos to photobucket, copy and paste the [IMG] URL into the reply box and it should display the photo.

59

Technical / New YZ Project

« on: October 19, 2013, 09:36:15 AM »

So, today, well I guess yesterday, October 20, I went and picked up the YZ. As I suspected the thing was bagged. The bike was in pieces, the cylinder was missing, bottom end siezed, bolts were mismatched, fenders cut, tires bald, air filter was so old that the oil on it was dry, chain rusted, and the list goes on. One of the weirdest things I found was that the clutch perch was broken, so the owner had wired it together with chicken wire and then taped it with electrical tape.  Anyways, looks like I have lots of work to do but I already got lots done today.

Thats upsetting... Although I'm not ashamed to admit I tacked a clutch perch back together with a 1200 mig welder in desperation to ride That was a great weld...

60

Technical / New YZ Project

« on: October 17, 2013, 09:43:50 PM »

I have done some research on the Athena 144 kit, and it looks like there are quite a few complaints about the kit, and it also requires modifications to the cases, which I would not be comfortable doing myself, so that would mean I would have to pay the local Yamaha dealer 100 bucks an hour to do these small modifications. So I found that Athena makes a 125 kit, it comes with everything I need, so I will be keeping the bike a 125. I really do not mind because I am used to racing a stock cr125 which is apparently in no comparison to a YZ125 motor.

Fair enough mate. Whatever way you slice it it'll be a blast to ride. Yes the CR motors weren't the best, but they could be brought up to speed. But that should have been done in Japan...