'77 XS400 build thread - cafe racer

I just got the hoop today, doesn't look all that great so I didn't bother trying to put it on.
IMG_2509.JPG
Instead I started pulling the bike apart to prepare the frame for powder coating. But I got stuck trying to remove the two front bottom screws out of the engine.
IMG_2519.JPG IMG_2516.JPG IMG_2517.JPG
They hit whatever that is in the middle which seems to be bolted on to the engine by just the one screw on its face. However, trying to remove it I noticed I was just damaging the edges on the nut but not able to turn it all.
Does anyone have any tips to get this out, do I even have to? Can I remove the engine some other way? By the way, what is "this" I am referring to called?
My last resort option is to just cut the screws.
 
That is the oil filter cover.

Drain the engine oil, remove the cover and filter, then remove the bolts.
You do have the earlier style motor mounts so you will have to get those bolts out to remove the engine.

That hoop looks pretty wonky. Looks like they kinked the pipe in a few places?
I guess their options are limited if the required radius doesn't match their bending dies.
 
That is the oil filter cover.

Drain the engine oil, remove the cover and filter, then remove the bolts.
You do have the earlier style motor mounts so you will have to get those bolts out to remove the engine.

That hoop looks pretty wonky. Looks like they kinked the pipe in a few places?
I guess their options are limited if the required radius doesn't match their bending dies.
Yeah the guy ended up chopping the tube into sections to make the bend. I was willing to accept the straighter curves but it's also not well shaped to take the profile angle leaving gaps when the seat sits on it which is why I didn't go forward with it. Guy did it for me for free as a favor while I visited his shop so I can't really complaint, I am just going to take the spare tubing I have and ask him to please charge me and weld it to the frame himself so I know it;s done with the right amount of effort.

As far as the oil filter cover. Why the f*ck is it so stuck. It should be a piece that has been removed before but it feels like it was never opened since factory. This picture is from the front of the bike. Either way, I am going to try to hammer in a 11mm tube into it and see if I can torque it open then.

Another thing I want to be ready is removing the tires out of the rims to take them to get powder coated with the frame as well. Any hints on where to read about removing the tires? I'll go search the forum for a thread in the meantime.
 
As far as the oil filter cover. Why the f*ck is it so stuck. It should be a piece that has been removed before but it feels like it was never opened since factory. This picture is from the front of the bike. Either way, I am going to try to hammer in a 11mm tube into it and see if I can torque it open then.

Not sure I understand the question here. You took the bolt out of the center of the filter cover and it won't come off? That does sound very strange to me. Did someone have a problem with the seal ring leaking and use some kind of sealant on it? Don't go getting too rough with it you don't want to do any damage to the cover or the crankcase!
 
Yeah, if the bolt is removed there shouldn't be anything left to hold it on. There's just an o-ring between the two surfaces.

If the bolt is stuck... that's a fairly common problem. People tend to waaayyy over torque those bolts. Enough that Yamaha started casting the tightening torque right onto them so people would get the message.

If the bolt head gets too rounded for sockets to grab your best option will be to weld a bar onto the head of the bolts and use that to apply more torque.
Unfortunately the threads are too deep for any kind of penetrating fluid to get at.
 
Yeah, if the bolt is removed there shouldn't be anything left to hold it on. There's just an o-ring between the two surfaces.

If the bolt is stuck... that's a fairly common problem. People tend to waaayyy over torque those bolts. Enough that Yamaha started casting the tightening torque right onto them so people would get the message.

If the bolt head gets too rounded for sockets to grab your best option will be to weld a bar onto the head of the bolts and use that to apply more torque.
Unfortunately the threads are too deep for any kind of penetrating fluid to get at.
I was able to get it out. My dad came by and lent me a hand. It is exactly what you describe, I chuckled at the fact you mentioned no liquid would get in cause you know I used too much WD40 trying to get it loose. I ended up breaking the bolt, the head was so rounded my dad got a chisel and started whacking at it to the point it made a slit in which the same chisel fit tight at just the right angle that the hammering blows made the screw actually turn loose.
I already found the replacement bolt on mikexs, its like $16.00. I'll just make sure to not over-tighten it when I replace the oil.
Good thing my dad also came by because he then helped me remove the engine out of the frame which was another big challenge. We turned it one way too much and then it was sort of crossed so that if one edge was about to clear a gap, then the other side would get stuck. However, after a while of pulling and pushing and lots of effort we finally got it out.
IMG_2554.JPG


It was too late by then though so I just put all my crap away since I have to actually use the place for work tomorrow.
But my next step is to remove the fork which I have to go do some research on how to go about this. I gave it a quick try while picking up the tools and removed the big bolt at the top but that didn't seem to loosen any obvious part. Im sure I will have a do'h moment once I actually look at how its done.
 
Bikes fully apart for the most part.
Still got take the tires off the rims (gonna have a tire place do it for me, dont wanna mess up the rim), the coils of the rear shocks (bought a ratchet strap and watched some videos) and this cylinder off the bottom tree thing which I have no clue how to pull apart.
image.jpeg
I'm going to take the frame to my welder friend to weld the rear hoop for the seat and adjust the width of the frame a bit so that the seat fits snuggly on. Also cutting the front fender and then getting it all blasted and powder coated.
image.jpeg
 
Haven't updated in a while but been quite active on my bike. After pulling it all apart, I have most pieces painted, just waiting on my wheels which are supposed to be ready for pick-up Monday but I wouldn't be surprised if they aren't ready. and I think the only pieces I am left to paint are the gear shifter and carburetor - which I will be cracking open soon to service.

Anyway, wanted to ask you guys what is the 14mm piston bore this product refers to?
https://www.mikesxs.net/parts/yamaha-xs650-master-cylinder-with-sloped-reservoir-oem-3g1-25850-00-00

I have an aftermarket master cylinder and want to return to something that looks more stock and since I have clip-ons, this seems like a great fit. That is, if they are made for a 7/8" bar.
 
The brake master cylinder is a hydraulic piston actuated by the brake lever that has a bore diameter of 14mm, the same as the stock xs400 master cylinder.
The 14mm means that it will have the same performance as the stock xs400 master cylinder.
It's listed for the xs650, which uses the same 7/8 bars as the xs400 so you should have no problem mounting it.
 
The brake master cylinder is a hydraulic piston actuated by the brake lever that has a bore diameter of 14mm, the same as the stock xs400 master cylinder.
The 14mm means that it will have the same performance as the stock xs400 master cylinder.
It's listed for the xs650, which uses the same 7/8 bars as the xs400 so you should have no problem mounting it.
Awesome explanation, thanks a lot for the info!
 
So I've gotten most parts back from the painter. Missing rear suspension coils and front mud guard.
Here is a picture of the engine soon after I painted it. (This one I did with a spray can myself)
IMG_0049.JPG
There was too much build up of shit - for the lack of a better word - and I didnt wan't to sand it much nor crack it open to get it soda blasted since the engine works great plus I neither have the knowledge to fix it nor the money to have a mechanic do it for me if something goes wrong when putting back together.
I still think it looks great, the rough texture it has here and there doesn't really bother me and it looks good back in the frame.
Now, the frame does look great. This was powder coated matte black by a pro and it came out great. I'm going to keep it as wrapped as I can as I build so there won't be any good pictures of it for a little while. but here is a shot of me doing some shenanigans while putting the engine back in the frame by myself.
IMG_0187.JPG IMG_0189.JPG
I laid it flat on my work table with some wooden pieces I had laying around to keep it as leveled as I could and it turned out to be rather easy to fit the frame around it. Considering I did it alone, I was pretty stoked, specially given how hard it was taking it out - with help.

Also, last night I installed the triple tree and forks. The forks were a real challenge for me. For one I wasn't really prepared (I had to come on to XS400 once or twice mid installation) and secondly, removing the fork cap by yourself is no easy feat. Either way, after last night I finally feel like I learned something which feels good. Pretty stoked for what's next in this building trip.
IMG_0203.JPG
It's already starting to look like something. I wish I had a close up of the upper triple tree because it looks great after the facelift.

Now a question/doubt I have: Is red and tacky #2 great good/decent for bearings? My napa guy told me not worry about buying chassis grease and bearing grease that a heavy duty grease should work just fine.
For the fork oil I bought SAE 10W30 as detailed in the manual btw.
 
Quick question, is part 10 as pictured below in both exhaust pipes?
unnamed.png
I only have two as pictured in the diagram but I figured both pipes should be the same and I should have 4 halves instead of two.
If I recall correctly, I had one per piper at the time I took the exhaust off.
What do you guys think?
 
yes, it takes 2 of the split collars for both pipes (so 4 total)
Thanks man, now I am off to find who's still selling these.

Actually, Wolfe_11B, I found another thread in which you shared a link for the same part for an '81. The one for that year is actually still being sold now my question is, do you think it'd be different to the one on a '77.
'77
'81
 
Last edited:
Your '77 takes the same collars as my '76 xs360 and the 78-82 years all take that same other part.
I just took the collars off my 360 to compare to my '82 and they are different. The 76/77 collars flare out to a greater outer diameter than the 81.
It's enough that you'd only have a very small contact area between the collars and the flange that holds them down.
Might be workable as a very last resort but I wouldn't want to.
 
hey, I did some maintenance today and was using the forum (clutch cable replacement and adjustment), then realized I never showed off how my build came out so here are a few photos. This is actually how it looked the day it was technically finished.. the plate is no longer there, its on the side now, rear axle mounted, the rear tire is a bit too big and it actually rubs against the underside of the seat pan.
20181016_104236.jpg


20181016_104226.jpg
 
Back
Top