GSX 400E -83 chopper

[MotoX]

I know I put this down in another thread, but with a bit of cut and paste I'll amend this fault and start a projectthread instead

Hello everybody

This is a post written from Sweden, not that weird actually since I myself am a Swede. I don't have a driving licens for these 2 wheel thingies yet but that doesn't stop you from tearing a bike apart and rebuilding it the way you want right?!

So, as the title mentions, I have bought myself a GSX 400E -83 and will chop this up a bit to make it more like I want it. I figure it is a nice thing to start on and if I get a good result I'll be moving up to other sizes in motorcycles as the time goes by.

There she is, or I should say was... She doesn't quite look like this today as she is missing a few parts here and there. Nothing radical has happened yet though as I am missing a weld machine at the moment, but that should be taken care of in a couple of weeks, by that time some bigger changes will occur.

The main plan will be to cut the rear frame of and weld a hard tail. I will try and find me some thicker wheels with a good thick profile so that it will be somewhat nice to ride on the lumpy roads of Sweden. Still havn't figured out where to find those wheels though but I'll keep looking and probably will find something nice. Any hints are greatly appreciated!

The other day I did cut off the original exhausts and assembled just enough parts to start the "monster" up, just to hear the possibly future sound of it. I soon realized that I might have choped of the exhaust just a tad too much, but I got the idea and now have something to look forward to. It is however missfiring alot and that should be due to the much leaner mixture that is a result of no air box and the more open exhaust.

Therefore I am now looking for a jet kit to the carburators but havn't had any luck so far. A small shove in the right direction from anybody who knows of somebody who sells this would also be very nice!

I'll be updating here as often as I can though my work require me to stay of anything social for extended periods of time, apparently they think that you have to actually work to get a salary, imagine that

Have a nice one everybody and thank you for a good forum!

To push myself along in this project and to keep some sort of aim I thought it would be a good idea to make a list of what to do here. I'll keep it updated as I go along and will add more things to the list as I make them up in my own dissoriented head. Most of these are not exactly written in stone...

• Frame
  • Clean of mounts that I wont need
  • Reweld to hard tail
• Brakes
  • Make new brakeline on front brake
  • Probably gonna stick to that drumbrake on rear, but would be nice to throw on a discbrake in the future
• Fuelsystem
  • Tear down carburators and give them a good clean
  • Jet carbs, preferably with dynojet
  • Restrict airflow to carbs with either pods or headers
  • Find me a nice tank that suits the build
• Engine
  • Adjust valves
• Exhaust
  • Restrict exhausts with baffles
• Wheels
  • Might be nice with a wider rim on the rear, nothing superwide, just an inch wider than stock or something like that
  • Find me a thicker rear tire due to that hard tail
  • Paint rims black
• Suspension
  • Change parts in forks for new ones
  • Change the oil in them (ofc refering to above)
• Electronics
  • Get rid of the components I don't need, mainly some of the indicators on the handlebars
  • New electric wires on the whole bike
  • Try and find me a smaller neater speedometer

Let's run through the costs so far...

• Bike - 600$
• Metal parts on jigg - 115$
• Metal parts on frame - 570$
• Tools - 400$
• Weld restoration - 600$

Total of - 2285$

 

[MotoX]

So, I was scrolling through some of the other threads here and stumbled upon the drawn out bobber one. This image struck my fancy as for the solution of keeping the swing and just welding to straight(?) pipes on there to make it into a hard tail.

I will certainly take a look into this on my drawing board, though I feel that it wont look pretty without the exhausts running along the bottom which I don't realy know if I want to do on my bike or not. Should I want the exhausts to go in any other way I think I'll have to get rid of the swing and make a new rear end all together. I have to say though that this bike realy looks nice the way it is!

 

[MotoX]

Started up a list of things that are in my head for the bike in the first post. I know what some of you are thinking "man that is alot of stuff for his first build, he will never pull that of" and you may very well be right, but you have got to have dreams right? Some of you are even thinking "what an idiot that wants to do that to a perfectly good bike" and well, they are my dreams, what can I say :dancing:

 

[Flyboy]

Well, as I said, I would rather have seen you hack up a an old bike that was in need of rescue rather than such a nice one, but it is your build, and your dream, so I have no doubt you will turn it into exactly what you are looking for.
I always appreciate good work, no matter what form it comes in, so I am following with interest.

 

[MotoX]

But it is your build, and your dream, so I have no doubt you will turn it into exactly what you are looking for.
I always appreciate good work, no matter what form it comes in, so I am following with interest.

Thanks for understanding!

 

[Flyboy]

Hey, maybe when you sell off the parts you won't be using, they can help to keep other 400's alive and on the road.

 

[MotoX]

Hey, maybe when you sell off the parts you won't be using, they can help to keep other 400's alive and on the road.

Indeed they probably will There are some good plastic parts, the tank, maybe the rear rim, the swing (probably), the controls on the handle. Should probably keep some other owner happy.

I'll be saving some stuff, like the tachometer, though for the garage so that I can read the rpm's when tuning and such.

 

[MotoX]

Spent the evening tearing down the bike to only have the frame rolling on wheels. That engine, even though just 400, is a heavy SoB.

I have been sketching fast in the computer and can't realy decide yet on if I should run straight pipes from the bottom back of the engine or if I should continue on the pipes running under the engine and then bend up when arriving at the rear wheel.

I guess it will come to me sooner or later. Meanwhile I will start cleaning up the engine, carburators and other stuff. Probably will put some stuff up for sale also on the market here in Sweden.

 

[Guest]

Well, not really a hardtail fan, but I am a fan of quality work, so show us what ya got

I found I could just lift my 450 up onto the work bench from the bin I had it sitting upside down on, but that was about it. Needed my mate to help me put it back in the frame.

Good luck!

 

[MotoX]

So Dynojet finaly answered my mail, sadly it wasn't a positive response. They answered in short that there are no jetkits to the GSX400 on which I replied the question if with the specs of my carburator maybe they could find a kit or seperate parts that might fit. I havn't got an answer to that yet but one could hope for a good answer this time!

 

[Johnny Drummond]

You could try www.allensperformance.co.uk they are knowledgable and very helpful,I was able to set up a sale or return arrangement(if you find that the jets aren't right and as long as they are returned in the condition they were sent,no scores damage to the screwdriver slots) they will work with you until the right jets are found.This was a very great help to me when I re-jetted the GSX1100 engine that I fitted into my GS1000 frame to suit the pod filters I had to fit because there was no room for the 2 piece airbox,I found a good way not to damage the very soft brass screw heads was to get a screwdriver that was just too small for the slot and dip it into the rubberised glue that you stick patches onto bicycle tubes once it has set it creates a flexible barrier between the screw and screwdriver.Hope this is of some use to you-good luck!!.Johnny

 

[Guest]

Following with interest...

 

[Guest]

So Dynojet finaly answered my mail, sadly it wasn't a positive response.

You can figure out the carb setting yourself (there is a page on the forum here) and then just order what you need from Dynojet.
I wouldn't be surprised if those are BS32 carbs with jetting similar to 750/850 in which case you could order that kit but for two carbs only.

 

[MotoX]

You can figure out the carb setting yourself (there is a page on the forum here) and then just order what you need from Dynojet.
I wouldn't be surprised if those are BS32 carbs with jetting similar to 750/850 in which case you could order that kit but for two carbs only.

Hey man, yeah I'll figure out which settings I have today, will dissassemble the carbs completely within a couple of weeks and figure out every detail about the setup. The only thing I know right now is what the service manual says, which is that they are BS34SS.

Will print the whole thing here when the dissmembering is finished

 

[MotoX]

So this is what I had to work with today

The guide at BassCliff's page helped nicely and in the end they both looked like this.

Yes yes, I know, "why didn't you clean them?!". Well I just don't have those chemicals yet But I got the numbers out of all the parts that needs changing for the jetting. I also sadly discovered that one membrane has a hole in it.

So that will need changing aswell. I'll go to the local bikestore in a couple of days and see what they have.

Here is the list of my numbers:
Jet Needle - 5D69 with washer on second lowest
Pilot Air Jet - 125 (12,5?)
Pilot Jet - 42,5
Needle Jet - 354 P-1
Main Jet - R 120

 

[MotoX]

So, looking in the service manual I can see a slight difference (which might not be so slight?). The Main Jet on my bike is 120 and should be 117.5 according to the manual. All other things is according to the service manual as long as the bike is a GSX400EX and not GSX400ET, and frankly I don't know, so should be a GSX400EX right?

 

[hampshirehog]

Beware the manual!

Which part of the world is listed on the front page (or 'early pages') of the manual? The carbs do vary a bit depending on the market - usually the US bikes were set up to run leaner than the rest of the world so your bigger 120 jets might be standard in Sweden.

Edit: Just checked and if your bike is a GSX400 1982 (SZ) European model it should have 120 mains.

 

[MotoX]

Beware the manual!

Which part of the world is listed on the front page (or 'early pages') of the manual? The carbs do vary a bit depending on the market - usually the US bikes were set up to run leaner than the rest of the world so your bigger 120 jets might be standard in Sweden.

Yeah it's a Haynes Manual printed in England.

Oh well, the thing for me to figure out now is what parts to change in to for my setup. If I can I will go with some sort of headers to the carbs and will probably weld a washer into the exhausts to restrict that air. So with the exhausts hopefully being like original in ways of air restriction I "only" have the air to the carbs to wory about. I guess I could make the headers tight but should probably need to rejet the carbs anyway right?

Should I change every one of those parts mentioned in previous post or just a few special of ones when i rebuild the air intake this drasticaly? Or do I simply have to test it out and change after testing once the rest of the bike is finished?

 

[hampshirehog]

Yeah it's a Haynes Manual printed in England.

On behalf of the English members on here I apologise for the Haynes manual. They are useful for lighting fires though.....

The chances of you being able to use the original carb settings if you are chopping the exhaust / throwing away the airbox are remote - even if you do start making restrictions etc. You will have to either run the thing on a Dyno or do plug chops to tune the carbs in when you're ready.

 

[MotoX]

The chances of you being able to use the original carb settings if you are chopping the exhaust / throwing away the airbox are remote - even if you do start making restrictions etc. You will have to either run the thing on a Dyno or do plug chops to tune the carbs in when you're ready.

Yes, plug chops is what I intend to do when I'm finished, but to take a chance on some sort of baseline, do I change every of the 5 components listed to the next part with richer mixture or do you normaly just change some of those parts when greatly added air is introduced to the mixture?