OzVMX Forum

Clubroom => General Discussion => Topic started by: fatboyracing on January 27, 2011, 09:15:11 pm

Title: YZ 250 84 / 85 model
Post by: fatboyracing on January 27, 2011, 09:15:11 pm: Here we go again I opened up a can of worms earlier about the hondas
Can some one tell me if the only difference between a 84 and 85 model YZ 250 is the disc brake front end?

cheers
Fatboy
Title: Re: YZ 250 84 / 85 model
Post by: Nathan S on January 27, 2011, 09:28:57 pm: 85 has the rear brake linked to the shock (BASS) - most riders disconnected them anyhow.

Barrel, head and power valve are different, but if my knowledge of the 84 vs 85 YZ125s is relevant, you could easily port the 84 to be like an 85. Base gaskets are the same part number.

Suspension linkage is the same.

Apart from the stickers, the cosmetics are the same - it would take a trained eye to spot a drum-braked YZ250N as being a 'faker' bike.
Title: Re: YZ 250 84 / 85 model
Post by: VMX247 on January 27, 2011, 10:17:08 pm: Quote from: Nathan S on January 27, 2011, 09:28:57 pm
- it would take a trained eye

you in training for level 4 Fatboyracing ? :)
cheers A
Title: Re: YZ 250 84 / 85 model
Post by: fatboyracing on January 28, 2011, 06:25:53 am: Hi Alison,
All ready level 4 scrutineer just brushing up on some of the difficult models
I think Dave T does a great job of eligibility and I dont want his job

I start my new job with Australian Superbikes next month looking forward to it

Cheers
Fatboy
Title: Re: YZ 250 84 / 85 model
Post by: head on January 28, 2011, 08:27:18 am: Cylinder and powervalve as Nathen said. Rear swing arm is slightly different as is the ignition, outer rotor vrs inner rotor on the 84. Easy to pick cylinder by model numbers in intake casting. It is not a follow on model so would not be legal as there is a advantage with the better top end. If you ran a 84 top end, put a drum brake front end on and removed the BASS suspension it would be close. But it is bending the rules. Its pre 85 and that is what we should stick to.