OzVMX Forum

Marque Remarks => Yamaha => Topic started by: Slakewell on January 05, 2010, 08:55:02 pm

Title: Shift drum for 73 yz 250
Post by: Slakewell on January 05, 2010, 08:55:02 pm
Ok this is last part I have left over from my YZ a stuff this the gear box shift drum selector that the forks ride in can take pics if you need them.
These allways broke at the front where the lever folk pushed and pulled 
Title: Re: Shift drum for 73 yz 250
Post by: Freakshow on January 05, 2010, 11:13:03 pm
IS this a for sale item ? picture and price please.
Title: Re: Shift drum for 73 yz 250
Post by: Slakewell on January 07, 2010, 09:09:42 pm
well it's an item I no longer need in collection, I dont know it's worth in $ , If you need one then it's worth much more. These had 4 pins on the front that cracked and stoped engaging the gears correctly so the dogs wore and 2nd and 3rd stoped working. They can be repaired with a little silver soilder and carefull drilling, I did make a stainless steel plate to reinforce my old race bike, There not much use unless you have a YZ A or B. My camera broke but I could use my phone. It is only the shift drum nothing more I kept a spare as these broke often.
Title: Re: Shift drum for 73 yz 250
Post by: Freakshow on January 08, 2010, 01:04:11 am
OK got you, im interested
Title: Re: Shift drum for 73 yz 250
Post by: Slakewell on January 08, 2010, 09:52:13 pm
I once sold a rolling chasis YZ,A to a bloke at pittmans I think  SA/do you know him?
Title: Re: Shift drum for 73 yz 250
Post by: Freakshow on January 11, 2010, 12:58:04 am
WHo was it > wasnt shonky sharpe was it ?

Any jow is the drum the one with the holes in it ? give you $50 for it
Title: Re: Shift drum for 73 yz 250
Post by: Davey Crocket on January 11, 2010, 08:10:00 am
Shonky Sharpe... thats being kind to him!!!!
Title: Re: Shift drum for 73 yz 250
Post by: Freakshow on January 11, 2010, 12:09:23 pm
Davey - Karma will come . . . .

I know of about 6x250 YZa in SA and 2 x360A the only loose frames i know of was with steve warne, but i thing Robert picked them up recently when he quit some gear.  so if its in SA could be anywhere.
Title: Re: Shift drum for 73 yz 250
Post by: Slakewell on January 12, 2010, 04:35:11 pm
WHo was it > wasnt shonky sharpe was it ?

Any jow is the drum the one with the holes in it ? give you $50 for it

The drum is a real YZ A shift drum I will take some pic's soon. I'm just away till Monday $50 is fine $40 for beer and $10 for postage.
I just happen to find a YZ-A 250 when I had an add in the local paper that said I payed cash for old bikes and one very sad YZ A turned up I payed $400 for it. I took the motor and electrics and sold the rest to the spare parts guy at Pittmans Yamaha Adelaide. dont remember his name. Told me he had 360 motor for it. 
Title: Re: Shift drum for 73 yz 250
Post by: Davey Crocket on January 12, 2010, 04:59:38 pm
Certainly sounds like "shonky sharpe".
Title: Re: Shift drum for 73 yz 250
Post by: Freakshow on January 13, 2010, 09:49:23 pm
YEp, sounds like him, he went on to raid (litterally) all the Pitmans NOS to build that bike into a mint 360, interest to find out its only a 250 frame by the sounds of it.

I got a 360a motor here in the Champion, but im on the hunt for a MX frame 250 or 360 as it goes like sting and love to see how well it hauls on the mx track.  Keep your ears open ....

Give me you Details and ill fire that money over to you.  Paypall or bank is easy enough,

Cheers Freaky
Title: Re: Shift drum for 73 yz 250
Post by: Slakewell on January 14, 2010, 01:46:48 pm
If I had a real YZ 360 motor the last frame I would use would be another Yamaha. The YZ's had all there wieght on the back they steered like shit which is why I sold all mine, light and very fast and they stoped but just didnt turn. If you could find the right guy you could copy a YZ frame but move things around so it steered, like moving the front axle 100mm towards the foot pegs, I wish I had time for a project like that.
You do know there is no difference between the 250 and 360 YZ frames? My Last YZ A had KTM forks fitted to it that helped a fair bit.   
Title: Re: Shift drum for 73 yz 250
Post by: Freakshow on January 30, 2010, 06:16:19 pm
Well if i can get some parts sorted im going to put the 360 in the 250 Mx frame for the nats.  Needs some rods people..............

any way you going to get back to me with the Drum ?
Title: Re: Shift drum for 73 yz 250
Post by: Slakewell on February 01, 2010, 07:42:39 am
(http://img188.imageshack.us/img188/4243/shiftdrum.jpg)

(http://img52.imageshack.us/img52/7164/shiftdrum1.jpg)
Title: Re: Shift drum for 73 yz 250
Post by: Freakshow on February 01, 2010, 01:27:49 pm
Shouldnt that have all the holes in it ?  looks more like a Dt unit
Title: Re: Shift drum for 73 yz 250
Post by: Slakewell on February 01, 2010, 07:03:45 pm
I have pulled apart 3 different YZA gearboxes and they all looked like this. It wieghs zip and is very hollow were the MX and DT are more solid. It came out of a YZ 250A. If you have never needed to pull apart a YZ gear box and own one you are most fortunate. The little pins on the front are what breaks the shift fork pulls and pushes these and they break or the holes they live in wear. Then the drum dosent turn far enough and the gears dont work.
Title: Re: Shift drum for 73 yz 250
Post by: Davey Crocket on February 01, 2010, 07:10:36 pm
Thats a YZB shift drum, the A was full of holes, the B was hollow but without the holes drilled in it!
Title: Re: Shift drum for 73 yz 250
Post by: Freakshow on February 01, 2010, 11:24:56 pm
YEs dave thats what confused me, last one i saw had holes in all gthe slots.

If its hollow and will fint in the "A" box im stillinterested though.  No dents on the shift channels are there ?
Title: Re: Shift drum for 73 yz 250
Post by: Slakewell on February 02, 2010, 08:53:45 pm
Its been 10 years since I pulled one of these apart , I have never owned a YZB or parts there off ,I cant remember holes dilled in the drum itself and as indents shift fork slide in these I dont see how they can.
The shift pins are not 100% and will need some attenion. It is what it is. My experance with YZA yamaha's allways came back to this part. It failes and then the dogs on 5th gear round off, The dogs on 5th pushes 2nd into 3rd gear and so on. I hope I have this correct but it's something like that.
Title: Re: Shift drum for 73 yz 250
Post by: KB171 on February 02, 2010, 09:12:53 pm
Dunno if this helps,but the shift drum in my 250B was the same as this when we rebuilt it,no holes .
(http://i49.tinypic.com/1o12r8.jpg)
Title: Re: Shift drum for 73 yz 250
Post by: Davey Crocket on February 02, 2010, 11:33:08 pm
If someone puts a picture of a YZA shift drum up you'll see it is full of holes...ala swiss cheese!!!. The A drum did cause problems and thats why they went back to a DT style drum on the B's, they are very trick motors and gearboxes when you see them apart....they would have cost a fortune to make and I would say pretty close to the early OW's/72 YZ.
Title: Re: Shift drum for 73 yz 250
Post by: Freakshow on February 03, 2010, 02:54:33 pm
HOpe to pull the 360 apart on the weekend if thats got one in it ill take a snap, Davey call me when you free i need to cut a deal with you for some of these parts to get the bottom end up and running, rather have all the stuff with me when i go to pull it down rather than be missing stuff ( mainly the rod and bearing) split and the refit it in the same day i hopes to.  Call a brother when you get a chance.  Also did you speak to your mate about the Shim clearance in the box ? if its apart i wanna check its all in spec, so any tolerances for the A model can you fick it to me, i got to do a rebore as well so ill size up the rings and piston too if i know the clearnaces there.  cheers freaky
Title: Re: Shift drum for 73 yz 250
Post by: Slakewell on February 04, 2010, 08:17:46 pm
Hey how about I just send it to you and you check it out and If you want it keep it. PM your address
I have no idea of you engineering skills but you will need some to get this perfect agian. I used to make a new stainless steel plate for end and then fill up the pin holes with silver solder and drill them new with a index gear on the mill and a short panel drill.You can make new pins from a needle rolling bearing.

Cheers Slake
Title: Re: Shift drum for 73 yz 250
Post by: Freakshow on February 05, 2010, 05:08:00 pm
OK Slake ...Pm sent.  ;)  cheers for that.

JOhn ----> did you read my post.  can you call me new Sim is up and running but numbers where on the old one