1982 xs400 project

[Tj_91]

Hey all, I'm very new to the site. I picked up a 1982 xs400 maxim for $200. Before I started tearing it apart, it ran and rode great! I'm hoping to eventually turn this bike into a bobber, but I'm a "novice" when it comes to mechanics. My number one priorities are to replace the front forks (they're slightly bent), replace the chain, update the fuse box to a modern one, and figuring out whether I want to leave the monoshock in or replace it with square tubing. Any advice or suggestions will be greatly appreciated! Pictures coming soon..

 

[drewpy]

welcome to the forum TJ

leave the mono in it if you ride it any distances

 

[16VGTIDave]

Welcome fellow Maxim rider!

I have to agree with drewpy, keep the shock. Comfort is valuable!

Dave

 

[bentwrench]

The shock does give some challenges when customizing, especially if you decide to run pods, and get rid of the air box, as the air box also holds your battery. You can look at my threads to see how I'm getting around it.

Hardtailing is possible, it all depends on the look you're going for, and how you are going ot use the final bike.

 

[Tj_91]

Thanks all for the advice! Bentwrench, your thread has been really helpful so far...and I forgot to post pics again....they're coming soon!

 

[Tj_91]

Its been a good while since I've had time to work on my bike, let alone post any progress (trust me, there hasn't been much ). Ah well, I've gotten back into it with gusto! So far I've gotten my front turn signals hooked up, started degreasing the engine, and am elbow deep in the stock carbs. Yeesh! I've got a friend with alot of experience showing me how to assemble/disassemble and clean'em. And re-clean, re-clean, re-clean.

I will have pics up as soon as I can, and as far as the carbs/airbox/pipes are concerned, I have put pods on and removed the stock mufflers. I've been following some of the threads on jetting issues, and think I have a decent starting point.

Now, for an extremely novice question; what model of Mikuni carbs are on my bike?
(1982 XS400J Maxim)
I have a downloaded copy of the manual from '82, and haven't seen a "mikuni" model number.

Thanks all for reading!

 

[16VGTIDave]

According to the manual, Chapter 7 page 1, the stock carbs are Mikuni BS34's.

 

[Tj_91]

Indeed it does....haven't had an occasion to look through that chapter

 

[Tj_91]

Update! After a vigorous cleaning of the carb, new oil/filter, and a new battery....it lives . And boy is it loud! This joyous occasion took place after replacing the fusebox with a modern blade type box, sorting some electrical bugs, and some profuse welding...

I did decide to ditch the mono-shock. As I live less than 8 miles (12.8 km for those on the metic system ) the "semi-rigid" qualities the bike now possesses aren't much of an issue.

Now to tackle the delightful headache that is carb jetting. Thanks to the detailed threads of those who have podded before me, I've started out with 150 main jets, and have my local bike shop acquiring 50 pilots (for $2 a pair I'll wait). I'll be post an update with any progress as soon a I can.

I'll try to get some pictures up too, but my computer seems to be on its last leg

 

[Tj_91]

Still no pictures, but I've finally gotten my carbs almost tuned....I say that because my top end (5000-7000 rpm) takes off like a rocket, and my bottom end (1500-3000 rpms) is responsive to my liking. Unfortunately, from 3000-5000 rpms the bike seems sluggish and hesitant. I've read all around this site that to properly tune the mid-range rpms the needle height will have to be adjusted. My question is HOW does one do this? Please help!!

 

[bentwrench]

http://www.amckayltd.com/carbguide.pdf

This is my bible for these carbs. It's written for the xs650, but we have BS34s, just like the later 650s did. There's a great section on tuning in the middle. Just remember all jet sizes are wrong for us, because they're made for a bigger bike.