Detailed Build Threads ?

[jmd_forest]

Gentlemen,

I've recently acquired a 1980 XS400 that I am planning to use as the basis for a father/son cafe build project. Although I'm well experienced in auto body, painting, welding, car mechanics (I've been rebuilding high end insurance wrecks as a hobby for 25 years) and bike mechanics (engine, electrical, carbs on my 1985 XJ700), I'm seriously lacking in imagination and design skills. That is why I'm planning to mimic the 1981 XS400 at http://www.barebonerides.com/the-bikes.html. (about 3/4 way down the page)

I've searched the site a bit but haven't seem any really detailed end to end build threads that could give me a better idea of the tasks ahead of me. Although I'm willing to go it on our own, it would be nice to avoid common mistakes and make sure I don't skip steps.

Aside from the general safety (tires and brakes) and obvious aesthetics (seat, handlebars) what are some of the "gottchas" a first time cafe builder can expect in building a mild cafe racer?

Is it a given to lower the forks?
Must the frame be cut and where (usually)?
How are cable lengths shortened (MUST they be shortened)?
Is there a guide for rejetting carbs based on PODS and/or exhaust?
Are there "go to" vendors for xs400 cafe parts?

Any help you might be able to provide would be appreciated.

Hopefully this post is not so noob I get laughed off the forum.

jmd_forest

 

[corruptmind]

Always good to ask questions. Welcome to the forum and everyone here loves pics. As for a few of the questions;

Shorten cables will be needed if you have the buckhorn bars. I haven't shortened my wifes cables yet and they're working ok, tricky to route them right to not be as ugly and still work. Throttle wants to rev when I turn hard at times, clutch was sticky at times, and front brake hose flexes and isn't as strong as it could be.

Most people generally cut the frame behind the shock mounts. You can pickup some cafe parts for certain sites but most won't list as xs400 specific. Things like wind screens are generally universal I'm sure you have a 7" headlight. Cafe seats are the same but often you have to make your own mounts.

Personally I wouldn't lower the forks. These bikes sit to low in my opinion. Id raise the rear with longer shock absorbers. You can get them and other things xs400 specific & universal at http://www.partsnmore.com Benefit of raising the rear is a decrease in rake and trail with results in a more flickable bike... though these bikes already are. But the most is clearance for more lean.

Carbs on these bikes aren't to bad. Get some jets and a colortune and benchtest yourself. That's the best and only real way to do it.

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[bcware]

First off, this is going to be a relatively painless build for you with the kind of experience you've mentioned. With no experience at all I found this motorcycle to be very straight-forward and simple to work on. In my opinion your worst enemy is rust depending on the condition of the motorcycle.

Aside from the general safety (tires and brakes) and obvious aesthetics (seat, handlebars) what are some of the "gottchas" a first time cafe builder can expect in building a mild cafe racer?

When upgrading to tapered steering stem bearings you'll find that the new, provided bearing seals do not work; re-use the original ones.

New turn signals, unless they are a larger, oem type, will need resistors or a new flasher for the turn signals to operate correctly.

Is it a given to lower the forks?

I would avoid this myself because these bikes are already quite low to the ground. For performance I often hear that a taller bike will tend to be more twitchy and responsive in terms of steering.

Must the frame be cut and where (usually)?

If you're buying/fabricating a new seat, yes. There are two places that commonly get the chop. First you can simply chop off the rear turn signal brackets to clean up the frame. Second, you can cut right behind the rear shock mounts. I have found no definitive answer as to whether the structural integrity of the frame requires additional bracing, but the most common approach is to replace what has been removed with a custom "hoop." If you're a taller rider you're probably going to want a longer seating area.

How are cable lengths shortened (MUST they be shortened)?

I have run clip-ons with stock cables successfully. It required some creative routing, but it worked just fine. Depending on your year and whether you intend to keep it, there may need to be some trimming of the stock headlight mounting bracket to clear the clip-ons.

Is there a guide for rejetting carbs based on PODS and/or exhaust?

I have yet to see an official guide where everyone can post this information, but there are several of us on here running all sorts of setups. If I know more about your mods I, and others, can get you started.

Also, be careful when considering which pods to buy. If you want to attach the pods directly to the carbs they must be a design that does not have an inner lip on the boot of the filter. Many cheaper pods have these lips and they block the small inlets on the face of the carbs.

For now here is a good general guide to carb tuning: http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,CV,high_rpm_engines.html

Are there "go to" vendors for xs400 cafe parts?

mikesxs.com is an xs650 site, but many parts are used on the xs400s as well (jets, hardware, random hard to find bits)

other general parts sites include www.partsnmore.com, and www.z1enterprises.com

These are the sites that I primarily use.

 

[jmd_forest]

Gentlemen,

Thank you for your help and opinions. I pick up the bike on Monday and am looking forward to getting started as soon as my son comes home from college on winter break. Prior to the cafe conversion but before he gets home my plan is to do a detailed cleaning/rebuild of the carbs to get the bike running smoothly since the PO notes that the bike starts and idles but dies when throttle applies. The carbs cant be any worse to work on that the 4 Hitachis on my XJ700.

Thanks again.

 

[Travis]

The carbs are about the same, just only 2 instead of 4.

For cables, you can get custom cables from Motion Pro.