Jump to content
Sign in to follow this  

Long time lurker with an XR400

Recommended Posts

Hi guys Im riding a 400.

Im 6'4 and 120kg.

Im riding dirt mud and sand, as fast as I can with minimal air time.

I have a polysport headlight.

All the gordons mods.

A CRF450x exhaust.

I have a 12.5 rear spring and a pair of heavy front springs coming this week.

If are new valves required? What impact would they have on my style of riding?

Share this post


Link to post
Share on other sites

I'd say, no, new valving is not "required". If you'd have thrown some rocks, roots and ruts in there, I'd say, for sure. If I were you, while you have the forks apart, do the shim stack mod.

Share this post


Link to post
Share on other sites

Whats the ''shim stack mod'' . I have my 97 forks apart waiting for some bushings to come in.

I noticed that my springs are a bit shorter that later years .

Welcome aboard large144

Share this post


Link to post
Share on other sites

Thanks guys.

Shim stack mod from what I can gather is removal of 6 of the 12 shims on each side.

Share this post


Link to post
Share on other sites

Its a standard '10 CRF450x exhaust.

When I got the bike it looked like a good fit, apart from the side bumper bits only 1/2 of one of the two hold the side plastics off the can.

I took the manifold/can off to do the grinding of the manifold and could not get the can back on with 2 bolts if I put the manifold on first. So to ensure a leak free seal on the block i put the manifold on first and used the clamp and the top mount to put the can back on. Havent had an issue yet. Touch wood. The bottom mount is mm away from working out. With a little work on the subframe it would be fine I think.

I cant really review it for performance its been on there the whole time. looks good and sounds alright?

Share this post


Link to post
Share on other sites

Its a standard '10 CRF450x exhaust.

looks good and sounds alright?

Thanks, any chance for some images, or even better a video? :smirk:

Share this post


Link to post
Share on other sites

Oh and I fixed the bottom mount. it just needed a spacer. Too easy.

This means the only fitament issue is with the mounts holding the plastics from the can. its not close its just they look out of place.

Share this post


Link to post
Share on other sites

Thanks guys.

Shim stack mod from what I can gather is removal of 6 of the 12 shims on each side.

So there is only 12 shims total? I would bet there is more info needed to perform this mod.

Share this post


Link to post
Share on other sites

So there is only 12 shims total? I would bet there is more info needed to perform this mod.

From what I understand, there is only 12 shims in the comp. stack that are all the same thickness. I've read most people take out 6, some like Dwight Rudder said he only took out 3 or 4 and then ran lighter oil (2.5W) at max height and had very good results. The goal of the mod was to reduce high speed damping.

Search the forums on 4strokes.com for a little more info.

Share this post


Link to post
Share on other sites

Got the heavy springs in and set the sag... (almost none in the front) and its a new bike. Very impressed.

I did not do the shim stack mod as the shop owner said he had done it to another and he ended up putting them back in as it did not suit the local terain.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...