1981 XS400 Engine Build: A Story of Pictures, Videos, Beers & Tears

burr said:
The clutch lever doesn't release the rear wheel to spin freely. There is good action at the lever, and I've greased the cable and worm gear in the sprocket cover. I even have a small spacer for the clutch cable (outside the sprocket cover) to tighten it up. Gives me good tension at the hand lever, but still no effect on the rear wheel!!!
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Have you adjusted the cable at the lever and done the adjustment with the nut/bolt in the worm gear?
Are you missing either of the ball bearings in the clutch push rod assembly? There's the one shown on the parts diagrams and there should be one inside the worm gear assembly that's not shown on the diagrams.
 
Yes, have adjusted the clutch at the lever end.
But.... What adjustment at the worm gear are you talking about? From what I examined, there's nothing to adjust. I also didn't see anything in the manual about adjustments to the clutch cable inside the sprocket cover. Seems like the only adjustment is the clutch lever's spring inside the sprocket cover.
If I missed the clutch adjustment section in the manual, can you point me in the right direction? Page number, etc :)

BBS360 said:
Are you missing either of the ball bearings in the clutch push rod assembly?
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Nope, definitely have both ball bearings in there. I can see the bearing inside the work gear assembly (and yes, thanks for confirming that - there's no mention of that 2nd ball bearing in the manual).
 
I should add that my clutch lever was a bit hard to pull while i was sitting still... but ive had surgeory on my left wrist and have a plate in there.

Once i was goIng down the road, the adrenaline kicks in and you dont notice anymore!
 
Ignore the two screw cover. It's under the rubber plug on the outside of the sprocket cover.
The spring isn't meant to be an adjustment.
 

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BBS360 said:
Ignore the two screw cover. It's under the rubber plug on the outside of the sprocket cover.
The spring isn't meant to be an adjustment.
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Riiiiiight. Forgot about the black rubber plug thingy.
I'll certainly do that adjustment. Here's the suggestion from the official Yamaha Manual
 

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So guys, bike should be all ready to start up, so I'm trying it now and…
Good News:
  1. Got some pretty excellent compression. 145psi right, 143psi–ish left. Happy about that.:cool: I put at most a tablespoon's worth of oil in the cylinders 4 days ago. So not sure if this qualifies as "dry" or "Wet" results. Took about 6-10 kicks (wasn't exactly counting). Pressure didn't drop for the 1-2 minutes i was looking at the gauge.
  2. Put in new sparkplugs: new NGK BPR7ES plugs, with new non-resistor NGK LZFH caps. Did them finger-tight, then tightened down 1/4 turn with a spanner. Trimmed a little of the old sparkplug cable off for improved connection.
  3. Battery is fine – rear lights and turn signals work as well as they ever did. So the battery definitely has some life it in. I smashed the headlight by accident, so I can't really test it out.
  4. Gas lines are fine to carburetor, and floats have gas in 'em, because i unscrewed the very bottom screw and it bled a little gas. (I did NOT vacuum sync it obviously, just bench sync'd so far).
Bad News:
  1. All i hear is a loud "click click click" coming from the battery when i use the electric start. Kicking the engine doesn't seem to do anything, other than spin the shit around.
FYI: I have a TCI setup.

Would love your guys' help and all suggestions, or maybe a checklist of things to do.
So… do i check the coils with a multimeter? The Haynes' manual pictures are pretty bad.
Fuses? I opened up the box, the fuses are intact (one is covered in tin foil, i didn't mess with it since I rode it 2 months ago though). I made sure the stator is connected to the battery.

What else can i check?
 
Yup, battery is discharged. needs to be charged up. while your at this stage, you can connect the bike battery to your car, as long as your car is not running. Your cars charging system will fry the system. (TCI, probably) with jumper cables.
http://www.xs400.com/media/albums/electrical-issues.345/
This is one suggestion on upgrading the fuse block. Since then, 3D printing has become a big deal. there is a posting within the last 5 months where someone posted a really nice 3D printed fuse replacement box. ( I would love to get one) replacement with Mini-blades. super nice.

http://www.xs400.com/threads/3d-printed-parts.13719/
 
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Cancel that guys, JUST STARTED HER UP!!!!!
She sounds like this: :gun:
Idle is crazy fast right now.
Needed a push start.
Smells terrible (probably because of burning stuff off).

Need to fix throttle hand lever, not connected right now…

BUT SHE STARTS
 
Thanks for ALL YOUR HELP SO FAR. Really felt like i accomplished something today.
Recommencing tuning tomorrow, ran out of time tonight.

A couple things before I take her for a real ride…

  1. The throttle doesn't spring back right now. Any tips how to do that?
  2. She's leaking oil out of the left cover gasket. Was using an impact driver/gun to drive the cover's bolts down. Might have to buy a new gasket/use Permatex.
  3. Carbs will almost certainly need to be tuned. However, they have all original stock components, and they are clean inside. Obviously this will hamper performance for a bit.
 
Uh oh, did I do a bad thing? I've been using a Milwaukee M18 Impact driver.

Also - any tips on adjusting the throttle?
My plan is to to examine where the throttle cable hits the carbs first, then move to the handlebars.
 

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