OzVMX Forum

Marque Remarks => Yamaha => Topic started by: Marc.com on July 14, 2011, 06:56:11 pm

Title: YZ250 A roach
Post by: Marc.com on July 14, 2011, 06:56:11 pm
Now the YZ is almost on the boat I am comtemplating my purchase and have a couple of questions for Ross, Freaky and anyone who has some more idea than me.

1. chassis parts are not a so big issue however, curious about the fork legs or lack of chromium on them, what fits in there place ( MX DT YZB)

2. pistons, rods etc seem fully available..... safe to assume the bore is dicked, sleeve or plating, which would you use.

3. clutch..... can DT actuator and casing be used in a pinch, I noticed on modified in an earlier post

4. Gearbox ..... if the box is completely shrapnel do i have the option of DT/RT gear cluster, I know they are different ratios.

Anything else that I desperately need to know.

(http://i245.photobucket.com/albums/gg71/marcFX_photo/2011-03-19_15-50-43_610.jpg)
Title: Re: YZ250 A roach
Post by: mx250 on July 14, 2011, 07:30:38 pm
..............curious about the fork legs or lack of chromium on them,........
The forks look right to me. They came standard 'machined down' without the mudguard mounts.

what fits in there place ( MX DT YZB)

MX are 34mm have about the same travel but are not machined down.

DT are 34mm have the less travel and are not machined down.

YZB are 34mm I'm not sure about the travel and are machined down (I think the axle mounts differently).

PS I hope it was cheap ;), there's a lot to be resto'ed there.
Title: Re: YZ250 A roach
Post by: Marc.com on July 14, 2011, 10:03:05 pm
( MX DT YZB)
MX are 34mm have about the same travel but are not machined down.
PS I hope it was cheap ;), there's a lot to be resto'ed there.
[/quote]

well that solves the fork issue as have clean set of MX250 forks in my war chest

BTW: yeah it was pretty cheap if you can do a lot yourself.... I paid about what NSW car rego, insurance  and green slip costs ... lucky I don't own a car  ;)
Title: Re: YZ250 A roach
Post by: Freakshow on July 14, 2011, 10:53:31 pm
id rechrome the ones in it, only cost $200 or so over here, your other legs wont have the same tapers.  having said that onther 34mm will fit but if you going to do that just use the whole fork and be dont with it if you making up a rider/bitsa.

And then pack up the fork and post to me ( payment ensuing)

sleeve it if it needs it ( then you have umpteen piston choices.)

YEs the dt covers can be cut down to be race covers or you can just the button cam if thats all you need out of it.  also im looking to find the specs for the sissor type ones  ( speedway style ) so ytou can do away with that system and also use it as a case saver.

yes you can miss gear sets in pairs, but remeber if its a genuine YZ box its square cut as are the pimarys.

you have abn easy base bike there to work on the.  the YZ dont have a lot of fluff so its only on the bike if it has a purpose so there easy to built up, unless you want a wanky 100 point resto in NOS then just remorgage the house
Title: Re: YZ250 A roach
Post by: Marc.com on July 14, 2011, 11:41:34 pm
unless you want a wanky 100 point resto in NOS then just remorgage the house

Nope no wanky NOS cheque book resto around here, thanks for the help, I think the forks look like they will stand rechrome as most of the rust is between the legs. I will pick my way through, still a few shafts and gears on Fleabay so looks like most things are possible.

Who would you recommend to sleeve it ?  BRG Marc
Title: Re: YZ250 A roach
Post by: Slakewell on July 15, 2011, 07:15:04 am
I run MX 400 B forks in mine from time to time as they worked better and were a straight bolt in.
The gear box was it's own special thing and only B parts fitted as far as I know, The dogs on the back of 5th were a problem as they changed 2nd to 3rd or something like that. I had them re cut and then sent the gear to heat treatment in Brisbane to be beefed up.
Sadly the easiest way to clean the air filter was to remove the rear wheel and mud guard.
I used a 92 YZ 250 carby as it was straight up fit and didn't need re-jetting adding a bunch more power.
The clutch always sucked and I never fixed it.
You can fix the original shocks to work OK but works performance were better.
Title: Re: YZ250 A roach
Post by: Marc.com on July 15, 2011, 07:23:05 am

You can fix the original shocks to work OK but works performance were better.

Yeah I had the same conclusion, I have a couple of sets of works performance shocks spare so they can go on. Interesting on the gearbox and the dogs being a problem, having owned a few Ducati's I probably have a different interpretation of gearbox issues.
Title: Re: YZ250 A roach
Post by: Slakewell on July 15, 2011, 07:53:26 am
I never found a oil the gear box liked so the clutch would slip or drag. I never tried to retro fit modern plates like I do on my KTM's now.The whole clutch set up is bogas.
Sadly they steer like wheel borrow with a flat tyre and an lose axle, I fitted 36mm Cerarnies forks which helped allot but the real problem being the engine is too far back so you need to ride them on the back wheel which isn't my style. The light weight is wonderful and if you can fix the clutch and steer them on the back wheel you will love it. 
Title: Re: YZ250 A roach
Post by: Marc.com on July 15, 2011, 09:49:43 am
Sadly they steer like wheel borrow with a flat tyre and an lose axle, I fitted 36mm Cerarnies forks which helped allot

Believe it or not I will probably resist the temptation to fit a fugly swingarm and will probably leave it pretty original. It is not going to be racer (thats the MX250s job), just part of my pre74 250 odysey.

Is that mob Jasco still doing liners and stuff in QLD ?
Title: Re: YZ250 A roach
Post by: JohnnyO on July 15, 2011, 09:56:06 am
Serco do the liners in Bris..
Title: Re: YZ250 A roach
Post by: Marc.com on July 15, 2011, 12:08:10 pm
Serco do the liners in Bris..

Ah Serco, not Jasco ... the mind wanders
Title: Re: YZ250 A roach
Post by: Slakewell on July 15, 2011, 12:13:27 pm
I'm not sure you would want to ride a MX after riding the YZ it's a very huge difference.
Title: Re: YZ250 A roach
Post by: JohnnyO on July 15, 2011, 12:15:29 pm
I'm not sure you would want to ride a MX after riding the YZ it's a very huge difference.
Yeah agreed.. i think they're chalk and cheese on the race track.
Title: Re: YZ250 A roach
Post by: Freakshow on July 15, 2011, 12:37:40 pm
I get them cut locally, $350 fitted, not sure on the liner only.
Title: Re: YZ250 A roach
Post by: bazza on July 15, 2011, 02:35:15 pm
Hey Mark has some of that glow in the dark water reached Tokyo? Not fitting a Fugly Swingarm, come on you can do it!!! Hope all is well up there,will catch up if you head down under, Johny old perhaps
Title: Re: YZ250 A roach
Post by: Marc.com on July 15, 2011, 03:15:48 pm
Hey Mark has some of that glow in the dark water reached Tokyo? Not fitting a Fugly Swingarm, come on you can do it!!!

Hey Bazza ...... we had a little Celesium 137 in the water the other day, little 135 in the beef and a little Iodine Isotope in the breast milk, so as long as you steer clear of water beef and breasts you are bloody laughing.

Johnny Old is about one month before I get back to NZ for maybe good so timing bad. Keep an eye out for me end of April, I will be playing the guitar with a cup outside of the Britomart ;D .... though I have been offered a gig as a PR officer for the Mana party. ;D