New XS400 owner in D.C. area

[betteron2wheels]

Hi Team!

Some info about me: age - 38, been riding since 1999, currently riding a DRZ400 and FJR1300. Have experience in MC, auto and diesel truck repair. Decently equipped shop with a little welding experience and a few MC restorations complete or in progress.

I just picked up a 1980 XS400 and a '72 CB350 at a local auction over the weekend. One will be for the Fiancé for a minor cafe project and the other I want to turn into a track bike. I'm trying to decide which, there's a ton of info and build forums for CBs and it seems less common with the XS400s. I'm leaning toward using the CB for the track but I wanted to ask around. I would like to read through some track bike builds for the XS and get some input about mods, aftermarket support and others who have done the same. Both bikes are in about the same condition, have been sitting for 15+ years, both engines are free, need all new rubber all around, cables, carb clean etc, basically barn finds.

The advantages to the CB:
It looks like the older CB will qualify for more classes in the vintage racing,
the XS has a 16” back wheel – would need to be re-laced to 18”
More build info online, aftermarket support

Advantages of XS400:
I can’t think of any off the top of my head – looking for suggestions

I’ll add pics as work progresses.

Cheers!

 

[willem]

how about you bring the both of them up to a good riding, well-adjusted level, and then decide which one you'd like to use for which purpose after riding them and getting to know them a little more intimately? It boils down to personal taste in the end..

Also you'll have to be a little more specific than '1980 xs400', that could be a few different models still. Pics help a lot

but on paper, the cb and the xs have similar performance although the xs has a bit more torque. But then the cb is lighter..

 

[Yamaguy55]

Having spent plenty of time with the Honda CB/CL/SL350s when they were new bikes, I will say they were justifiably popular, but the XS 400 has it beat in a couple of areas. The cam bearings for the Honda are those caps on each side of the head. The cam sort of floats in there. If you run dirty oil, or if you don't clean the centrifugal oil filter (under the front cover on the RHS of the engine), or insist on hillclimbing or wheelies, the cam gets oil starved and is toast. The crank is a built-up one, like the Yamaha XS650s, and merely requires oil flow, not pressure. They seldom if ever give problems, nor does the clutch or transmission. Honda did a nice job on these excerpt for the cam and valve adjustment eccentrics. The cam chain tensioner is manual and requires attention as well. The cam chains are often toast by 15-20K miles. But the crank and transmission are trouble free. Assuming someone changed the oil and used suitable oil.

The XS400 has better carbs than those Keihins, although not that much better. The plain bearing crank is one piece and tough as an anvil. the cam bearing concept is better, and you seldom see them with cooked cam bearings. I think the adjusted screws for valve adjustment is marginal at best, as they leave divots in the top of the valve stems that affect getting a decent clearance reading. Our modern bikes with shim-under-bucket are harder to adjust, but the adjustment lasts and lasts.

The oil filtration on the 400 is drastically better, and the valve seats can tolerate unleaded gas, which the Honda doesn't very well. The Hondas were made when there was lead in the fuel, and low octane gas was 98 octane.

Neither one has great suspension, but the Yamaha lends itself to having an variety of other Yamaha suspension components bolt right on, where the Honda does not. You can fit the front end from the most of the XS range directly on the 400: the SR500, XS650 and most others of that era used the same steering head bearings, so you can swap out the entire front to a better setup. The Radian was the newest and most advanced bike to fit that criteria. the swingarm is also similar to other models and has the same Frankenbike abilities.

The Honda was a nice upgrade from the former CB/CL72/77 models. It was a simplified CB/CL450 engine, which was a very good one. But Id say the Yamaha frame is a better design: it is a slightly modified RD350/400 frame (taller to fit the taller four stroke engine) where the hybrid pressed steel/tube Honda from was very typical of what mid to late sixties designs though good. Well made, but low tech. More like no tech. Still better than that horrible Honda "Dream" pressed steel thing. We always made fun of them at the shop I worked at and called them nightmares, not dreams.

So there's your pros and cons. of the two, I'd call the XS400 slightly better overall. The Honda is a 325cc, the XS is just about 400cc. If you have the post '79 model, you don't have to fiddle with points. The Honda points system were good when everything was newish, but once cam and other wear got in there, it was a pain.

 

[betteron2wheels]

Willem,

That would be a great way to do it, but I think I need to chose one and go with it. I would like to have something ready for spring and I’m short on bandwidth to do both, too many other projects going on.

Actually, nowhere on the bike or title does it say “XS”. I assumed it was by age and engine. I just realized I won’t be lacing a new rim onto the back; it has mag type wheels, front disk, rear drum and a small sissy bar and serial # in the 11000s. No pics yet

Yamaha55,

Wow, thanks for the info, I still haven’t seen any track day builds and need to understand vintage class rules better. If anything, the front disk might disqualify it which means I might have to steal the front end from my R5; I wanted to put a front disk on the R5 for street use anyway…any idea if a 13mm master cylinder would be a good match for the caliper or a good 18” donor back wheel?

The 1st thing I plan to do with the CB once its running well is to update the timing components, anything to look out for on the XS?

I’ll probably move this conversation to the technical section soon

Cheers!

 

[xschris]

Welcome to the forum It will be nice to see what you come up with.

 

[willem]

I did a thread about the things to look out for on the xs:

http://www.xs400.com/forum/showthread.php?t=11473

and a thread on the first steps of servicing:

http://www.xs400.com/forum/showthread.php?t=10595

 

[betteron2wheels]

Thanks Willem, I'll head right over there. Let me see f I can figure out how to post a pic...Yep, there she is, complete except for key. I started spraying all of the hardware with penetrating oil last night.

 

[Yamaguy55]

Still looks better than the one I'm fiddling with.

The RD wheels and stuff go right on with minimum mods. The last run of RD400s share exact parts. Not all, but a lot. I have a set of DS7 wheels I'm considering installing on mine. That way, I can fit any rim I want. I don't have much use for 16" rear rims. But that was the rage when it was built.

Those double leading shoe DS7/R5/RD front drum brakes are real stoppers, the only drawback being they are cable operated. However, with a fresh heavy duty cable and proper adjustment, they are almost as strong as a disk. They just cool off slower. I think the first model XS650 used a variant of that drum. (it definitely was a drum) I'm sure the cable would fit. There's the cable upgrade right there.

The master should work fine. I'm using one from another project, a much more recent Yamaha one that is for a late 80s bike. Sorry, can't remember which model. If I find a number, I'll pass it on. I have Superbike bars fitted, so the crazy tilt of the S model master installed on those bars (and the shape it was in) prompted the change.

 

[betteron2wheels]

Good input Yamaguy55, if I decide to make a track bike out of this I can swap wheels and brkaes from my R5 and track down a RD400 rear 18" mag and swing arm for the R5. I know that people like to put longer swing arms from a RD400 or (Ithink) a DT. I still haven't found any track builds. Does anyone have a link to one? My next post will be in the build section.

Cheers!