OzVMX Forum

Marque Remarks => Yamaha => Topic started by: hampster on February 16, 2009, 02:33:09 pm

Title: 250 d chain tension fix
Post by: hampster on February 16, 2009, 02:33:09 pm

Hi,

Seen the yz chain guild fix.
What do think would be a good set up for my 250 d?
At the moment i am running std set up with chain tension at rear and running over a fixed block at the pivit point, this looks like it could derail at any time.
Would a small wheel ran at the back engine plate spacer bolt position help?

thanks Chris.


 

Title: Re: 250 d chain tension fix
Post by: ARN on February 16, 2009, 04:40:02 pm

hi   i have removed the tensioner and been using ktm type sliders on the lower part of the swingarm in front of the sprocket .i also put a roller under the chain on the frame where the stand bracket came off. i have done this to 2 aluminium after market swingarms but it would be easeir to adapt to a metal swingarm       will try to get some pics up

Title: Re: 250 d chain tension fix
Post by: brent j on February 16, 2009, 08:14:21 pm

I fitted a roller to my mates YZ250D and he's very happy with it.
We welded a small lug to the frame so the roller sits below the swingarm pivot. With a spring loaded tensioner the chain is tight on the drive side but becomes loose on over run. With the roller, the tension stays constant.
He says the difference is noticable.

I can get a pic but it won't be before the weekend at best.

Brent

Title: Re: 250 d chain tension fix
Post by: hampster on February 16, 2009, 08:42:51 pm

Quote from: brent j on February 16, 2009, 08:14:21 pm

We welded a small lug to the frame so the roller sits below the swingarm pivot.

Hi Brent,

did you use the rear engine plate lower spacer treaded section to fit the other end of the roller bolt?

Chris.

Title: Re: 250 d chain tension fix
Post by: brent j on February 18, 2009, 07:09:43 pm

The bracket is on the plate that mounts the swingarm.

We never thought to look at the engine mount plate......................

Title: Re: 250 d chain tension fix
Post by: holeshot buddy on February 19, 2009, 09:08:15 pm

chris i put one of those spring tension adj jobbys
on my rm370 works great no problems 8)
mcs sell them at most bike shops about $35 bucks i think
bill might have one :o
when are you picking up cr250rc
saw it today nice bike ;D

Title: Re: 250 d chain tension fix
Post by: Husky500evo on February 20, 2009, 09:06:32 am

Or you could build something really different like one of these Luft hydraulic tensioners .

Title: Re: 250 d chain tension fix
Post by: hampster on February 20, 2009, 05:24:52 pm

Quote from: holeshot buddy on February 19, 2009, 09:08:15 pm

chris i put one of those spring tension adj jobbys
on my rm370 works great no problems 8)
mcs sell them at most bike shops about $35 bucks i think
bill might have one :o
when are you picking up cr250rc
saw it today nice bike ;D

Looked at fitting spring tension set up
have not found a spot on the frame to fit it ?

Mybe the hydraulic, does this pass pre 78?

Pick up the Cr next week ready for tambo.

Chris.