Bandit 400 restoration

[VW_NUT]

How are the spring rates on rear shocks from either a bandit 1200, or hayabusa?  

Reason I ask, is I figured the average rider is probably 180-200 and what is ideal for you might not be for my gf..  

[Red01]

How are the spring rates on rear shocks from either a bandit 1200, or hayabusa?  

Reason I ask, is I figured the average rider is probably 180-200 and what is ideal for you might not be for my gf..  

The Busa is 13.1 kg/mm and they figure the avg rider to be 165 lbs... according to the Racetech site.  I don't know what the spring rates are for the 1G or 2G B12's and Racetech doesn't have the info for them either (nor the B4's rear shock for that matter).  I do know the 'Busa's spring is much stiffer than the 2G S model's spring (naked 2G's have a stiffer spring than the S model).

[VW_NUT]

So you are saying we'd be better off with a shock from a bandit 1200 than a busa. 

[Red01]

Given a light weight rider, yes.
Not only is th Busa shock stiffer than the B12, it is also longer than the 2G shock, which is longer than the 1G shock, so if you're trying to keep a low seat height without messing with the geometry of the B4's progressive linkage, there's another strike against the Busa piece... despite it being a higher quality unit.

[VW_NUT]

Thanks If I were to make a slighly longer dog bone to lower the bike 1" or so, would it screw up the linkage?  I plan to drop the forks the same amount to keep things equal.  Thanks again guys for all the helpful info.

[Red01]

In addition to lowering it, the longer dog bones give more leverage against the shock, which gives the effect of a softer unit in all regards.

[PitterB4]

On another topic related to your restoration...  I read the posts over on the Monster board (nice write up, BTW!).  I saw that you had to replace some missing o-rings when you put in the jet kit.  If you didn't already, I would HIGHLY recommend replacing them all the next time you're in there.  If you do any reading here, you'll see that they can make you bang your head against a wall.  I'd replace them all before you start any serious tuning.

[hangin_biposto]

Hey guys, just wanted to let you know I've posted some updates in the other project thread. (Figured it was easier to link to it instead of playing the copy/paste game).

Here's the link again:
http://www.ducatimonster.org/smf/index.php?topic=95269.0

[VW_NUT]

The bike runs as of this weekend.  Sounds and feels pretty good although I may have to use Tomac GTI's write up to change the valve seals.  It is a little smokey after you rev it up when the rev's come down & the motor had been sitting a while.  We will see after it is run some more. 

Also, I cut the header just after the collector to install the slip-on muffler.  What is up with the collector on the factory header??  There are like 3 pipes in there.  One is pretty small maybe 1.5" or 1.75".  It took some work, but I smahed out the smaller one with an air chisel to open up the stock collector.  Is this a common mod to the stock collector?


Next project is to sand/prime/paint the tank.

[tomacGTi]

I'm on the DML as well. I ride with a bunch of the DeVal guys and I use the same screen name.

The smaller pipe inside of the header collector is a silencer. DO NOT cut the divider in the center of the collector, it acts as the 2-1 portion of the pipe and helps the bottom end. If you do cut it out, the tubes aren't optimised to run 4-1 and it will run like crap and be a total bitch to tune (think drag bike). Everything will be on the super-high end and will not be happy in the midrange.

The only difference I can tell from modding the collector was more noise. I changed too many things at the same time to relate differences. Getting silencer out of the collector out was a bitch because there's a weld that joins it in there layered up with some perf'd pipe as well. I didn't have an air chisel so I had to do it the old fashioned way. The inside portion I cut out with my Dremel and smoothed the weld with a drum sanding bit. I figured I just made myself a poor man's header.

Also, since you have your muffler apart, repack it. The F1R from Cobra was notoriously deafening. Doing the collector mod isn't going to help matters any.

To make sure it is indeed your valve stem seals, remove the header from the head. Take a look inside the exhaust ports and look at the stems themselves. If they look like a kid's nose in the winter (all runny and such) they're toast. You can also look down the spark plug holes at the piston top. If it's oil soaked, there's your problem. It isn't unusual for a motor to smoke a bit when it's fired up after awhile especially after doing some work to it. It will be very apparant leaving stoplights though as it was full-on Spyhunter for me since the seals were so shot.

Best of luck.

-Randy

[hangin_biposto]

So since the collector has already been hacked up, now what?
I guess the lesson here is to ask before instead of after...

[gsxr400 racer]

i said before but way back in the day there was a guy that raced a bandit and modded the collector in the header and did a write up about it that post is so long gone and he also had some dyno charts with some other info. I only remember fragments of it but wish i would have saved it any one remember his name? Also there is a link floating around of a total motor rebuild write up in japan or some where that is about a bandit 400 some peeps have seen it lots of pics and detail about tearing apart a bandit 4 motor would be nice if some one posted that again id like to save it for future reference.
cheers
Jay

[tomacGTi]

I wish I knew that that header mod post existed. I wonder if it can be found somehow.

Motor rebuild link from Japan:

http://translate.google.com/translate?sourceid=navclient&hl=en&u=http%3a%2f%2fwww1%2eodn%2ene%2ejp%2f%7ecde33290%2fFeelingOver%2fTechnicalWorks%2fBandit400Racer%2dEngOH%2ehtm


Alright, so you super-hacked your collector, not all is lost. Here's what I would do before damning it all to hell (which I do often, btw). Just to make sure, we are talking about the flat-ish piece of steel in the collector just after the merge of pipes right? If you didn't do anything to that, I'd say you're OK, disregard all of my blabber.

-Run it and see if you can deal with it. You will have to re-jet but you can see if you can live with it.

-If you have access to a welder, cut an access port with a cutting disc into the side of the collector and try to replicate the divider. All it is, is a piece of flat steel shaped just so. It floats somewhat after the pipes enter the collector. You should see the vestigial remains from where it was before since it's welded in. I would cut it open on the side facing the motor so you'll never be able to tell. Don't cut into the pipe that your exhaust clamps onto but the collector itself. A little black paint and you'll never be the worse for wear.

-Get another header, stock or otherwise.

[VW_NUT]

just so we are clear, I did not remove the separator, but only the restrictor silencer & smoothed out the area..  Thanks for all the info!  This place is a great resource for these bikes..

[gsxr400 racer]

thats the best link needs re wrote tho