My XS400 build/restoration thread

[Lego]

I created this thread as a log of my future restoration/modification of XS400 that i own.
In my intro thread i posted a few pictures and first steps that i did on the bike, and i will continue here.

This is the bike:

From the picture it seems that bike is in very good condition, so why just not start it and enjoy? well, overall it looks very good, but when you look closer, you will see a lot of rust, bad maintanence and small problems. Overall the bike can start, but revs to the max with the choke on, and without it just dies. I bought it from czech guy, who had it few years in garage and never touched it, original owner was from Germany.

So the engine is running, but very badly, brakes were completely frozen, there are few thing missing (some buttons, mirror, side cover,) and another stuff.

First step is to get it running smoothly so it will be rideable, and i will get a registration. In Slovakia, only way to get a registration for a motorcycle, is that it will be in its original condition, so any modifications will be next, after the bike will be registered.

Work on progress!

 

[Lego]

First thing that i done was brakes.

Front master cylinder and lever was very rusty and dirty so i decided to go the easier way and just bought a new one. Rear master was fortunatelly only dirty so after a good clean and rebuild with original parts, it worked. I also rebuild both calipers, cleaned them, changed seals and in the rear one also piston, which was pitted. For now, i reused the old brake lines, they look OK, but later i will change them. So both brakes are fully functional, this is Done.

Next, carbs.

Today i removed carbs from the bike. I will dissasemble them and will clean them in ultrasonic cleaner in local motorcycle shop.
Previous owner was not very carefull so the screws were half way to be stripped, but fortunatelly with a little patience i managed to unscrew all screws from top and bottom.

As you can see, somebody who was working on the carbs before, broke on of the float pin towers, on the right carb. As many other people here were experiencing the same issue, i believe its common mistake. The float pin is holding very tightly on the next tower so i believe that will be not a problem.
What is the problem is how to remove the pins. I read on the forum that you have to be very careful when removing the pins, because the towers can break (well, PO wasnt) so i proceeded carefuly. But without success. Both pins are holding very tightly, i tried to heat the towers, cool it with cooling spray, i tried WD40, but nothing worked. I am afraid to knock harder, because i dont want to destroy another tower. Any tips or tricks what to do here?

 

[xschris]

http://www.xs400.com/forum/showthread.php?t=10312&highlight=float+pin+repair&page=2 Check this out

 

[Lego]

Thanks xchris, i saw that, maybe i will try to repair the tower like that. But my actual problem is, that i cannot remove the pins, they are stuck there, i really dont want to break another tower..

 

[xschris]

I have used socket or a wall set on the other post as a brace while tapping the pin out. Or a small set of wire cutters to get behind the head of the pin to genitally pull them out.

 

[Lego]

I have a question about intake manifolds. The OEM stock have bigger inner diameter from carb size and smaller from engine size.
Like this (i hope you can see that)

Because mine are cracked, i want to buy a fresh pair.
When i looked on ebay for example this one: EBAY LINK
or mikexs, this one: MIKESXS LINK

Those replacement look like they are the similar inner diameter from both ends. Is that just a picture? or they are like that for real? If yes, can i use them? i suppose it can be a problem if they are not like the OEM.

OEM from Yamaha are crazy expensive (i can buy a pair from ebay for the same price as one OEM)

thanks

 

[xschris]

The one in the pics look to be one of those restricted hp one for new riders. The ones in the ebay link look right.

 

[Lego]

oh.. i didnt know that. now I am checking technical documents for the bike and it looks like that I own the 20kW (33hp) version. what a shame. how many HP has the normal version?

Because the old manifold which I have are actually with different inner diamater.

OK and lets go deeper in this one: what else is changed between normal and restricted version? are there any topics about this? can i change something and make it "unrestricted"

EDIT: the bike is from Germany so I suppose its for sure "restricted version"

 

[Lego]

I found one thread here with restricted version: http://www.xs400.com/forum/showthread.php?t=8193

now i am sure that i have the restricted.

Well, change the manifolds is no problem.
There will be probably different jets in carbs, that can be changed, no problem.

But the problem is, that i read, that maybe also camshaft is different for restricted and full version. and that can be problem, maybe

here i found camshaft on ebay from germany and it says that its for 27HP version .. which is 20kW, which is restricted version.
http://www.ebay.co.uk/itm/Yamaha-Ca...pt=UK_Motorcycle_Parts_13&hash=item51c21dda21

So i will need to open the engine and check it, and compare dimension with normal camshaft. does anybody here has dimensions of standard camshaft for SOHC?

can there be more stuff that restrict horsepower?
1. manifolds for sure
2. jets i believe
3. camshaft for sure
4. what else?

I have to make sure about jets, that will be done this week.

EDIT:

thanks to ondrej91 i am now sure that camshaft is different also:

here should be the dimensions (from german XS400 forum)

- 2A2 '77 Model 38 HP(open):
Intake cam. ... 39,29mm +/- 0.05 ....... Wear limit: 39,28mm ........ hub: 7,53mm
Outlet cam: ... 39,57mm +/- 0.05 ........ wear limit: 39,42mm ........ hub: 7,57mm

- 2A2 '77 Model 27 HP(restricted):
Intake cam. ... 37,29mm +/- 0,05 ....... Wear limit: 37,14mm ........Hub: 5,29mm
Outlet cam: ... 37,34mm +/- 0,05 ........ wear limit: 37,19mm ........Hub: 5,34mm

 

[oslocafe]

I´ve been looking for this a long time, I love this forum! I´ve got a 82 special from germany, with 27hp(probably less), need to get that restriction eliminated it because highway cruising is not fun at all. Probably getting a UNI filter pod with higher flow and a bit more open exhaust will help on hp(with rejetting)

Open questions to forum masters:
-what parts on the camshaft need to be replaced?
-on the DOCH tread they mention ignition module swap, does this allso apply to SOHC?

 

[Lego]

oslocafe you have to replace whole cam shaft, its one solid part.
I dont know about ignition module yet, its need more investigation.

But i think that replacing jets in carbs, manifolds, and maybe ignition unit can be good for adding power. not 38HP probably, without camshaft but some of it for sure. But this is only my theory.

 

[oslocafe]

good to know, impossible to come by a camshaft that is not 27hp & from germany though, been looking for hours

 

[trzcina2]

Yeap. XS 400 with 39mm camshaft is like a GEM in Europe. I'm quite glad i got it

 

[Lego]

True. And its also discontinued part. US source is the only way to get it.

 

[trzcina2]

Good luck!

 

[Lego]

trzcina2 i would like to know the part number of your ignition module.. can you check it sometime and let me know? because if you have the open version i will compare with mine if its really different or not.

 

[trzcina2]

hello,

I don't have part number, but i know i have "old school" type ignition with points. Like this one.

 

[Lego]

hello,

I don't have part number, but i know i have "old school" type ignition with points.

Fuck, I am stupid .. i have also points.. so in this case, there is no ignitor unit (i believe its called CDI).

 

[trzcina2]

Haha.

Exactly there is no CDI. BUT if you thinking about rewiring whole bike, you should think about changing your ignition to newer, electric type. It's much easier to maintain, than points. Unfortunately i realized that after i rewired whole bike... So i'm stuck with points

cheers.

 

[xschris]

FYI they are called TCI ignitions. Transistor controlled ignitions It will help when you are looking for one.