Putting it back together - need help

[mcrissjr]

Currently installing my fresh motor back into my bike. The motor is in and mounted (the SOB..) but i have a couple questions, as i took it apart 6 months ago and forgot some things.

1) I got two brand new carb holders, the rubber bits that mount to the heads and carbs. There's two metal rings that came with, along with four gaskets. What are these for? I gathered two of the gaskets mount between the rubber and the head, what are the other two for? And the two metal rings I can't figure out what they're for. Also, there is a little metal tube coming out one side of both of the carb holders. Which way are these supposed to be facing, and what are they for? I do have a little hose that looks like it might connect them with some twists, is it just to equalize pressure?

2) I went to install the sprocket cover and no matter what i do, I can't get clutch pressure. It had plenty before I removed it, i practically have to push the clutch lever back in place. I have the clutch cable going through the metal bit to get into the case, then it goes down and hooks into the spring loaded bit. Is that it? Am I missing something here? Any specific trick while installing it to get it right? Does the clutch rod turn or push in?

 

[freelancethink]

1. Pictures would be helpful.
The do the rings fit over to the intake manifold (the rubber tube connecting the carburetors to above the intake valves)?
When you say 'gasket' are you referring to o-rings or a paper gasket?
The tube that comes out of each manifold is used to measure intake manifold pressure when synchronizing the carburetors. The tubes should face up and each should be covered by a rubber cap and a kind of clamp that seals off the tube.
2. Consider removing, inspecting all of the clutch parts you removed and reinstalling everything in the order and using the procedure outlined in the service manual. I don't have the clutch assembly in front of me but they generally consist of a cable that actuates a clutch that 1/4 turns outward which pushes a push rod that engages the clutch and separates engine power from the clutch basket. Ensure everything is install and lubricated as required by the manual.

 

[drewpy]

and you really need to tell us which model you have

 

[Drewcifer]

mccris, you need to readjust the clutch cable adjustment. Theres a nut under a rubber cover on the left side of your engine, sprocket cover. Read the procedure. its in the manual.

to post pics, upload them to your xs400 album, go to each images page and cut and paste the bbcode below into a post like this. we will see the photo instead of the code.

Good luck

Drewcifer

 

[phate]

The tubes should face up and each should be covered by a rubber cap and a kind of clamp that seals off the tube.

If you still have the stock petcock one of them needs to exposed to attach the vacuum line (probably the tube he is referring to in his post) that supposed to go from the petcock to one of the barbs.

 

[mcrissjr]

It's a 1981 Special II.

Got the carb holders sorted. They're mounted, carbs and airboxes are on. All that's left is tank, exhaust, and this damn clutch.

Some pictures attached.

With the thing hanging off, if i pull the clutch lever and release, it slowly goes back, and this is the same when I have the cover on...

 

[drewpy]

cable maybe naff or needs oiling.

did you adjust it like drewcifer said?

BTW you're missing the black tube seal on the gear shaft.

 

[mcrissjr]

There's currently no oil in the motor, could that have anything to do with it? I will try to adjust it. There used to be plenty of pressure, now its like it's not doing anything.

 

[Drewcifer]

yes, that's exactly what happens when the adjustment goes loose or changes. It's a very simple procedure. You'll remove the rubber cover, loosen the philips screw inside the bolt, then break loose the nut that retains the push rod. All is now loose. Then slowly tighten the philips screw until it's getting firm, then back it off 1/4 turn, then tighten the nut AROUND the screw (slide a philips through a socket, you won't need the wrench attached to do this) by gripping the socket and turning with your fingers, other hand frozen on the philips screwdriver, keeping the screw in place. It's in the manual, which is your new best friend! After that you adjust at the handlebar.

Good luck,

Happy riding.

Drewcifer

PS, that being said, if the cable snapped in the middle it would feel like you describe. Does it still pull the arm visible inside the case? if not, it has finally snapped and must be replaced. They're not the most robust cable in the world after 30 years of use!

 

[mcrissjr]

Got it! It was a combination of that and me not tightening the cover down enough. Now I just have a squeaky lever.

 

[mcrissjr]

Now can someone explain to me how the exhaust mounts

Edit: scratch that, i'm a moron. had it right but thought it looked wrong.

 

[arfstrom]

Oh, I suppose you have the panel back on? I noticed your Clutch Thing, with the spring, (technical term) has the same thing with my system. I used a dab of JB weld, to fix my Problem. The Hole where the spring goes, looks elongated. A little dirt gets on the spring, and you clutch 5 times to get up to speed, and at least 4 times to de-Celerate, That dirt eats up that bit of metal, my spring actually sprung, and the hole I suspects didn't have long to live. Yours maybe fine.

Okay its a clutch spring. I will be taking that off my bike in a month or so. I can post if it has held up for the last two months of riding it, like that. I had to replace spring. I am also jealous of you luck Dogs who can still ride though out winter.

 

[mcrissjr]

Can someone tell me what these are for? Extra parts and can't make otu where they are supposed to go.

 

[Drewcifer]

Mcriss, my pleasure, there are three essential bolts to hold that cover on. Bottom left, far right, and center top. The rest are redundant, if you ever lose them, make sure they are the ones you have. The pressure of the clutch relies on the correct fitment of that cover. (ask me how I found out, d'oh!)

Those look like a component mount. Like maybe a regulator or something. I can't quite tell. but the rubber mounts indicate a non grounded metal component like the old mechanical regulators. Mine has a similar design but the pieces you have there are integrated on mine. So it might have bridged the machining on the battery box with a newer cheaper choice in mechanical regulator, ie, those make the new part fit the old holes since they didn't want to retool the battery box. Just a theory.

re Artsfrom: Nice save!

 

[arfstrom]

I think its your Motor mounts, I believe you use them to attach to the top of the engine to the frame.
Kinda looks like a number 2 on the Frame parts schematic breakdown.

http://www.partzilla.com/parts/search/Yamaha/Motorcycle/1981/XS400SH/FRAME/parts.html

Of coarse if you read the parts thing, its says its Obsolete, You need it. Its a Stay Engine 3.

 

[arfstrom]

You weren't asking about the hose? that looks like the hose that goes from the intake boot, to the fuel petcock. Seems too long for the fuel to carb house. And of course the tools get put away after the bike is running, Whats left? It looks like you just left with a couple loose nuts. Good luck

 

[drewpy]

Can someone tell me what these are for? Extra parts and can't make otu where they are supposed to go.

those are top engine mounts, make sure you put them in the right way round or you'll feel those engine vibes ( don't ask me how I know)

the washer rubber thing goes towards the engine

 

[Drewcifer]

Drewpy I bet the ladies wanted lots of rides until you fixed it.

 

[cafenewb]

Sorry if this is hijacking this thread, but I think it's completely relevant and if I were to create my own thread it would be the same title. Maybe others will find it helpful when looking at this thread.

I'm also putting mine back together, roughly, before I do some painting. There is a particular wire from the clutch lever that I was wondering if I need. Honestly, I don't even know what it does (total newb here). It leads into the cluster of wiring in the headlight, then into the wiring harness. What is it, and do I need it? thanks all.

 

[mcrissjr]

Sorry if this is hijacking this thread, but I think it's completely relevant and if I were to create my own thread it would be the same title. Maybe others will find it helpful when looking at this thread.

I'm also putting mine back together, roughly, before I do some painting. There is a particular wire from the clutch lever that I was wondering if I need. Honestly, I don't even know what it does (total newb here). It leads into the cluster of wiring in the headlight, then into the wiring harness. What is it, and do I need it? thanks all.

Can't see the pic dude. Upload it somewhere else.

I have not made any more progress, been busy plowing. Hopefully tomorrow.