My XS400 build/restoration thread

Thanks xschris, good to know. Actually my plan is to stay with the setup as it is. For some reason i like points. So even when I will be upgrading bike from restricted to open version I will keep the points. Its funny, because my profession is partly electricity, but with bikes I like more the mechanical stuff :)
 
My 79 still has the stock points in it and works just fine. As long as you keep them clean and adjusted you shouldn't have any issues.
 
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well after a month i got finally some time to continue with my project.

Today i cleaned the carbs, and i have two questions to you more experienced guys.

1. Float bowl cover does not cover the same area as the gasket sits, there is one small hole around which goes the gasket, but not cover, the one with the arrow

08637a9c-05c4-4c09-8613-43324f97867e.jpg


is that OK?

ebe040a5-9e5e-458c-a7af-a008ead2be8b.jpg


2. What is the correct float height for brass floats ? Haynes sais that its 32mm, but I think that is too much, my floats were on 20mm from PO (maybe one of the reasons why it did not run properly). I read on the forum that 26mm is good height? Should i go with 26mm?

thanks
 
This is how it should look. 26mm is about what it should be with brass floats. Just measure both sides of them. Sometimes they can be twisted a bit. Also measure with no gasket on it.
 

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Thank you xschris! That is exactly how it looks on my carbs also.
Ok I will go with 26mm. I see on your picture that the "tongue" on floats which is used to set up height, is straight. So are mine and i measured 20mm without gasket. So can it be possible that my floats are bent down? Or just bend the tongue to 26mm and leave it? Because i was really surprised why there are both straight and why i measured only 20 mm height. Previous owner must have change it for some reason, strange.
 
I have rebuilt dozens of these carbs for the xs650 and 400 and it always seems to be with the tang just about flat or so. Just measure to be sure:wink2:
 
Make sure the float valve needle is the correct one. It should be all metal. This would also cause a difference it height.
 

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Today i finished carbs!

thanks xschris, the float height is set to 26mm, i checked float needles, they are all metal.

Here they are, they dont look the best, but they look way better than before.
20150322_213740.jpg


what was done:

- dissasembled and cleaned in ultrasonic cleaner
- sprayed with carbcleaner, rubbed with silicone brush
- all jets and small parts cleaned with carb cleaner and inspected
- all important passages sprayed and checked
- changed shaft seals
- floats set to 26mm
- changed all screws
- bench synced

cannot check if they work because bike is not ready to be started, so i have to wait if the cleaning and rebuilding was succesfull. lets hope it was :D

As you can see on the picture, I am missing choke shaft knob, any hints for replacement? searched ebay but no luck. I saw some funny knobs made from dice, or small 8ball. Or should i made something on my own? any hints?


next to do:

- change fuse box to blade type (ordered)
- check all electrical components and eliminate faulty parts
 
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I will sure sync them when once i start the bike :)

today i changed fuse box, the old one was rusty and was missing one fuse (PO just twisted the cables together, very clever)
20150328_191735.jpg

Dont mind the mounting, its just temporary, i have to make some proper mounting plate for it. I just want to be sure that i used correct fuses, because in Haynes manual there is mentioned that XS400 has only 2 fuses (strange), i have:

main - 20A
headlamp - 10A
signal - 10A
ignition - 10 A

is that correct please?

Tomorow i will start checking electrical components. From the brief check, headlight and back light is not working, i have to figure out why. Other lights are working well.

One more question: When i turned on the main key switch, oil and neutral signal light turned on, and stayed ON. for neutral i understand that is OK, but I am not sure for the Oil signal light. Should it stay ON until you start the bike? i did not start yet.

Thanks
 
Fuses are correct. Oil light should go off with the motor running. It's triggered by a pressure switch.
 
Yesterday i checked electrical components, all lights are OK, horn, electric starter also. What else (before starting engine) should i check?
I measured coil resistance, but got some weird values, than i found that i have to measure primary coil WITHOUT sparkplug CAP. Can you help me understand how the caps are terminated on the sparkplug wire, can i undo them and then put them back on? are they crimped, or screwed? any pictures will help :)

I also checked valve clearences. Interesting thing was that both intake valves had correct clearance, after 30+ years.. maybe somebody before me did some maintenance. But both exhaust valves were out of range. That was corrected, next thing will be cleaning points and set up timing and clearence on them. Then i will probably check camchain tension, do you think that can be done with engine on the bike? or it will not be possible to take top cover off.
 
The cam chain is self adjusting so you don't need to worry about that. The spark plug caps should screw off. It is a good idea to clip about 1/4 in off each end before putting caps back on. If you are using non-resistor spark plugs use a 5k ohm cap. If you are using a resistor plug (BPR7-EIX) use a non-resistor cap.
 
I am starting the engine cleaning procedures, there is 30 year old gunk and dirt baked all over the bottom and also underneath left cover (clutch and sprocket cover)
i need to have the engine completely clean before first start, so it be more easy to check for leaks.

I have two questions:

1. best way to remove front sprocket? i am planning to lock rear wheel, use the chain to hold sprocket and try to loosen the nut. should i be worried about something during this? the nut is shallow so hopefully it will not strip.

2. can i take out the clutch pushrod ? i think its just sticked inside, there is some seal, can i just take it out, and put it back after cleaning?
 
Put the bike in gear with the rear wheel down is a good way to loosen the nut. Yes you can just slide out the rod but make sure you don't loose the bearing that is at the other end. Sometimes they roll out and get lost.
 
Thanks, that helped, sprocket is off.

I want to buy gasket paper and cut my own gaskets for some covers, for example oil screen cover. original gasket is not available anywhere around me.

do you think that gasket paper with maximum operating temperature 120 degrees celsius will be OK for that cover?
thanks
 
That should be fine. But remember the better the material the longer it will last. You don't want that one to fail while going down the road.
 

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