Clutch spring length dt250mx 1978

[G Digger]

Hi guys it’s me again.

i’m just trying to find out what the correct length of the clutch springs are for my 1978 dt250mx.

my Haynes manual suggest 36.4mm.

my manual I downloaded suggests 34.9mm.

the ones I got from yambits are 34.7mm.

ones for sale on autodoc suggest 36mm

thanks in advance

[NE0]

Interesting Digger, I don't know the correct length, but I do know it's probably best not to mix and match different springs. ..........Having said that, had I been doing the clutch back in the 70's/80's I wouldn't have cared about the length or even mix and matching them!!, as long as they weren't broken! and I would have ridden the bike regardless......and I suspect everything would have been fine.

Today, I might be a bit more cautious like yourself and try and get the right lengths.

although as long as they are all the same, will 1.7mm (the difference between the smallest and largest) make a big difference?

I don't sound much help!!.....I'll shut up!

 

[Snakebite68]

In all honesty, and within limits, the length of the spring won't matter.
What will matter is its strength...
A couple of mm either way in length won't matter, but a thicker or thinner wire will (it's not the length, it's the girth!!!).

It may even be the case that the slightly longer ones are 'upgraded' ones, or just 3rd party and not quite in spec.

If you're really worried or suspicious, go to your local Authorised Yamaha Dealer and get them to order you a set for your specific bike.
It may cost a few quid more, but you're guaranteed they'll get the right ones..!

 

And just to answer your questions directly..:

1/ My Haynes manual suggest 36.4mm.
The problem with Haynes is that the bikes they take apart for the manuals aren't new (one assumes that would cost a lot to disassemble a brand new bike), so measurements that small may be... Slightly off...

 

2/ My manual I downloaded suggests 34.9mm.

WHAT manual? I trust nothing off the interwebz completely!

 

3/ The ones I got from Yambits are 34.7mm.

Yambits are usually pretty good and I use them a lot, but I did get some petrol tap seals from them that were VERY much oversized (thickness) and were useless (so fat they locked up my tap).

 

4/ Ones for sale on Autodoc suggest 36mm.

Never heard of Autodoc...