Messages

1

Tech Talk / Re: 1975 Yamaha YZ50B Pistons

« on: April 27, 2015, 07:46:44 pm »

Thanks for that tip, it all makes sense now to me on part numbers now, I found https://www.motorcyclespareparts.eu/yamaha-parts/yamaha-model-prefix-motorcycles-1970-1994.aspx which lists the first part numbers to give the model. It shows :

431 is YZ250A     
432 is YZ360A
483 is YZ250A       
483 is YZ250B       
484 is YZ360A       
484 is YZ360B

using this reference the piston advertised now on ebay as std 250B piston has a part that starts with a 432 number so is in fact a 360 piston.

2

Tech Talk / Re: 1975 Yamaha YZ50B Pistons

« on: April 27, 2015, 05:37:52 pm »

Thanks, I will try those references, I seen some advertise std pistons that list both 1975 250 and 360 YZ but obvious they are different bores. Seems on Yamaha parts they share the same part number which confuses. The ebay ones I got answers on were actually 360 pistons.

3

Tech Talk / 1975 Yamaha YZ50B Pistons

« on: April 27, 2015, 01:57:31 pm »

Hi all, I have a 75 YZ250B race bike on a standard bore that needs new piston kit, these don't seem to exist anymore, I have heard some bikes have a 5mm spacer fitted below the cylinder fitted and then run a Yamaha TY250 piston? I can not find any prior comments here on this. Can anyone give me a link or comment if this is a good solution? Is it as simple as adding the spacer or are other issues then requiring adjustments for? At least those pistons 74-75??) seem to be available for easy purchase.

4

Tech Talk / Re: 1975 YZ250B Spocket cover

« on: September 05, 2014, 01:49:48 pm »

Thanks everyone, that helps me understand it all

5

Tech Talk / 1975 YZ250B Spocket cover

« on: August 31, 2014, 09:33:32 pm »

I am rebuilding a 75 YZ250B to race and it is close to completion, a harder project than I thought as parts are getting hard to find, I am still looking for a standard size piston but that is not stopping me yet, my problem is the bike has the original sprocket cover or minimal cover if you like but the Regs state I must cover the sprocket? Not use the original setup that everyone actually raced at the time?  Unless I fix that I cant race it? What do people use? does DT2MX cover fit onto the bike? All help appreciated.

6

Suzuki / Re: 1974 TM400 Resto nearly finished.

« on: August 29, 2009, 09:29:47 pm »

Not yet ridden, that's the next step, but it's a sweet bike

7

Suzuki / Re: 1974 TM400 project

« on: August 29, 2009, 09:24:57 pm »

Finally got it all together

8

Suzuki / 1974 TM400 Resto nearly finished.

« on: August 06, 2009, 08:45:55 pm »

It's been a year since this bike project started, getting close now.

The bike that made grown men tremble in fear..... real men only need apply.

9

Tech Talk / Re: 1974 Honda CR125 32mm Mikuni carb jets

« on: June 25, 2009, 04:19:59 pm »

Thanks fellas, I will give them a go

10

Tech Talk / 1974 Honda CR125 32mm Mikuni carb jets

« on: June 23, 2009, 08:16:22 pm »

Does anyone know what jetting specs should be used on a 32mm Mikuni for a 1974/75 Honda CR125? The standard settings on the 32mm dont work.

11

General Discussion / Re: Transport east west

« on: June 09, 2009, 10:48:54 pm »

Great help... I paid $750 for my last transport to Perth

Thanks

12

Suzuki / Re: Suzuki TM400, 4 Pound Flywheels Make them rideable?

« on: April 06, 2009, 02:38:34 pm »

No problem, I may be ready to sell it in 3-4 months as I am getting too many bikes, I have more restos coming about then.

13

Suzuki / Re: Suzuki TM400, 4 Pound Flywheels Make them rideable?

« on: April 06, 2009, 01:01:49 pm »

Thanks, I am 90% complete on the resto, only cosmetic stuff to go so have not ridden it yet - the urban myth of these things throwing riders off in uncontrolled surges was a concern for me but sounds like it worth a go first.

I also have TM250 about 90% complete and will be riding that one for sure.

14

Suzuki / Suzuki TM400, 4 Pound Flywheels Make them rideable?

« on: April 06, 2009, 12:40:13 pm »

I have a 74 Suzuki TM400 under restoration and would think about giving it a few race days once its done if I could tame the motor, I have read that in its day you could buy 4 pound flywheels that bolted straight on and made it a much better ride but have never seen one or even if you can still buy them anywhere, has anyone came across these or know where to get one?

15

Kawasaki / Re: 74 KX125 Wins 125 MX Shootout!

« on: April 06, 2009, 12:35:28 pm »

Your right about riding it, I will take it to a race meet and give it a run, more fun than just staring at it.