[coreyjdl]

this question is to answer some of my next steps in modifying my 81 xs 400 and maybe it will help some other owners.

what size k&n filter actually fits the mikunis?
what is the smallest sealed battery that will keep the bike running and starting strong?
anyone actually race an xs400 at ahrma or any other vintage events?
anyone ever had their xs400 over the ton?
does your xs400 wobble like a mother fricker over 85?
does the front fork need braced or can it be ran sans fender?
is there anyway to turn the petcock off?
are the megacycle cams worth it?
is there a weakspot in the frame? engine?
are there any xs400 specific quirks that every owner should know about before diving to deep?

anyone experienced w/ an xs400 help us who are new owners.

 

[kenessex]

Corey,
I haven't seen anyone race an XS400, but that doesn't mean it can't be done. It would fit in lightweight vintage superbike. If you are planning on racing it then I would swap out the front end for something bigger and newer. I would also get a set of 17" wheels for a better selections of tires. Check out the AHRMA rules. Vintage superbike is a pretty good class for working on the bike. You can do lots of stuff although the original bodywork rule is kind of stupid. The top bikes in the class are the Honda Ascot and SR500 based bikes. I run my CB350 in the class and it can do okay on a shorter track. I think the XS400 could be real competetive with some engine work. I would start with a stock fresh engine, Mikuni VM32 carbs, exhaust and suspension work and see how it goes. If you are not an experienced racer, it will probably be faster than you are for a season or two.

Ken