I recently acquired an '83 xs400 seca. It's missing parts (gas tank, gauges, etc.), but it runs. I was thinking about modifying it, to give that 'cafe racer' look.

The look is easy enough to accomplish, but how about improving the handling?

I'm quite capable in the garage, but I am used to working with much newer bikes. (I realize this will never perform like the new ones, but I'm sure it can be better than it is...)

Would a 2-into-1 exhaust help/hinder performance? (a friend had a gs450, got more power with stock pipes)

I have nothing invested in it currently, so spending a few hundred won't kill me. But if I can, I'd rather do without buying anything I can make/modify in my shop.

Any useful tips would be greatly appreciated

I recently acquired an '83 xs400 seca. It's missing parts (gas tank, gauges, etc.), but it runs. I was thinking about modifying it, to give that 'cafe racer' look.

The look is easy enough to accomplish, but how about improving the handling?

I'm quite capable in the garage, but I am used to working with much newer bikes. (I realize this will never perform like the new ones, but I'm sure it can be better than it is...)

Would a 2-into-1 exhaust help/hinder performance? (a friend had a gs450, got more power with stock pipes)

I have nothing invested in it currently, so spending a few hundred won't kill me. But if I can, I'd rather do without buying anything I can make/modify in my shop.

Any useful tips would be greatly appreciated

It seems to me that a 2 into 1 exhaust would increase backpressure and reduce the engines power delivery. Unless the total outflow and pipe diameter was bigger than stock that is. Perhaps some slightly oversized exhaust pipes/header and larger jets? I'm not much of a mechanic (just learning), but it seems like any changes to exhaust will have to be matched with changes on intake to make them count. You could also probably find a high flow air cleaner.

As for handling, I'm not sure. There might be some upgrades for your bike out there, or maybe you can make it a frankencycle with some front forks off a newer bike.

Before you touch the engine, you should service the front forks, rear shocks and all the brakes.

Before you touch the engine, you should service the front forks, rear shocks and all the brakes.

I agree with Yoda in that it would be best to upgrade the brakes and suspension first.it's alot more fun to have a good handling/braking bike that may be alittle slow than a fast wobble that scares you!

Indeed, progressive springs in the front forks, and progressive shocks in the back do wonders for everything. Brakes of course can be done up, even simple things, like drilling a solid rotor for that better grip in the rain - weight be damned.

Indeed, progressive springs in the front forks, and progressive shocks in the back do wonders for everything. Brakes of course can be done up, even simple things, like drilling a solid rotor for that better grip in the rain - weight be damned.

Iv'e drilled mine and added an extra disk a la XS1100.

disk patterns here

https://macshot.de/rd/brakediscs.html

Iv'e drilled mine and added an extra disk a la XS1100.

disk patterns here

https://macshot.de/rd/brakediscs.html

I bet that looks wicked too. Looks aside, the actual improvement it wonderful. If I still have my Milling machine in a month or so I may drill the disc on the XS500 before I give it to a friend.

I bet that looks wicked too. Looks aside, the actual improvement it wonderful. If I still have my Milling machine in a month or so I may drill the disc on the XS500 before I give it to a friend.

I used a bench pillar drill (£30 from Aldi) and an expensive drill bit for stainless. takes bloody ages though!

I used a bench pillar drill (£30 from Aldi) and an expensive drill bit for stainless. takes bloody ages though!

I believe it. The drill bits I have, plenty for metal work... but drills are all wearing out at the same time! Still, might be worth while for the XS500, hadn't thought of just using a drill, now I shall deffinately keep that in mind.

I believe it. The drill bits I have, plenty for metal work... but drills are all wearing out at the same time! Still, might be worth while for the XS500, hadn't thought of just using a drill, now I shall deffinately keep that in mind.

I think its called a "cobalt drill bit" which is well 'ard and did my 3 disks and is still going.

If you have access to a (bridgeport) mill, and some small carbide end mills, it's pretty quick work...

So, is there any one place to go that has a supply of parts for this bike?

I thought I read somewhere of somebody upgrading the monoshock by swapping in one from another, larger bike... tried to search, couldn't find it again.

The brakes are easy to take care of, I have all the source info I need at the moment. Mostly, it's the suspension I need help with...

If you have access to a (bridgeport) mill, and some small carbide end mills, it's pretty quick work...

So, is there any one place to go that has a supply of parts for this bike?

I thought I read somewhere of somebody upgrading the monoshock by swapping in one from another, larger bike... tried to search, couldn't find it again.

The brakes are easy to take care of, I have all the source info I need at the moment. Mostly, it's the suspension I need help with...

if you search the forums and put in "xs400 monoshock" there are answers there

I did try that; It got me nowhere.