Yam_Tech314's official build thread

[G_YamTech_314]

SHE LIVES. Got my first ride on it on this beautiful spring day. I’m thinking there’s some slack in the cam chain... hear nothing at idle, but some chatter/ slapping sounds coming from the exhaust, and down towards the back of the cylinder. So I have the manual on how to adjust it... but I want some help and advice on this procedure... dumb question, but can I do this without draining the oil, and can the motor be warm?

Also not sure if my head gasket leaks oil... but I got her nice and hot, and noticed some oil on the cylinder. I’m excited, because I have all gears in my transmission, have really smooth power and an easy clutch pull, and set my idle speed to a pretty smooth 1350rpms. <— that’s a rough estimate but on the gauge it’s just under 1500. I kept her under 5k rpms from what I can guess, because I’m worried about the cam chain slap, or whatever that noise may be...

My starter likes to stick for a few rotations when the bike fires up, not sure if that’s due to a low battery charge or if that’s just a common feature. Just adding every observation I can think of.

My left side carb leaks because the brass fuel inlet came out, and needs glued in somehow to reseal it. So there’s a small leak and I’d bet that’s where it’s coming from... other than that, I’m happy as hell that I got to ride a bike that I bought. This has been the first bike I’ve purchased that I’ve been able to ride in my life. A proud, and lively moment for sure!

 

[Jim]

... dumb question, but can I do this without draining the oil, and can the motor be warm?

Yes and yes. A lot of guys adjust it with the engine running. I don't. I just rock the crank back and forth with a wrench on the alternator rotor.

My starter likes to stick for a few rotations when the bike fires up,

That's not unusual. I wouldn't worry about it.
Congrats on the ride!!

 

[member28833]

Way to go YamTech ! You timed your initial test ride with Spring , Perfect !
I like to watch the cam chain adjuster action with the bike on center stand, plugs out. And then you can put her up in say 2nd or 3rd gear and manually rotate the engine by the rear wheel.
Thought I would try the "adjust while idling"
method but haven't the need apparently.
Keep us posted on your XS

 

[member28833]

My starter likes to stick for a few rotations when the bike fires up, not sure if that’s due to a low battery charge or if that’s just a common feature.

Save your starter for "when needed" ?
Enjoy the kick starter, Its just more Fun !

 

[5twins]

I don't care for the static method of adjusting the cam chain outlined in the shop and owner's manual. It's very easy to screw it up. Adjusting the cam chain while the engine idles is pretty much foolproof. You can also hear the effect it's having, or demonstrate to yourself what a really loose chain sounds like (loosen the adjuster way up until the motor starts making noise, then tighten it back up until the noise goes away). While idling, the plunger in the end of the adjuster bolt will bounce in and out slightly. This is what you want, about 1mm of in-out movement. If the plunger isn't moving at all, you've set it too tight.

 

[G_YamTech_314]

How do I see if the plunger moves? I simply screwed it in hand tight til I couldn't move it by hand, and then a 1/4 turn with my wrench and called it done.

 

[G_YamTech_314]

I don't care for the static method of adjusting the cam chain outlined in the shop and owner's manual. It's very easy to screw it up. Adjusting the cam chain while the engine idles is pretty much foolproof. You can also hear the effect it's having, or demonstrate to yourself what a really loose chain sounds like (loosen the adjuster way up until the motor starts making noise, then tighten it back up until the noise goes away). While idling, the plunger in the end of the adjuster bolt will bounce in and out slightly. This is what you want, about 1mm of in-out movement. If the plunger isn't moving at all, you've set it too tight.

Are you talking about the tiny hole in the end of the threaded piece? I’m used to self adjusting tensioners... this is a bit new to me... once I install the cover, and turn it in by hand, what else is there to check? Just wanna make sure I get it done right.

 

[G_YamTech_314]

Never mind... looked into it a bit and see that it should actually move about 1-2mm out of the end of the threaded piece. I don’t recall seeing anything move in and out when I adjusted mine. Does that mean it’s still a bit too loose? I’m guessing 1-2mm is pretty much the sweet spot? I got the noises to go away... took it for a second ride and boy oh boy am I hooked. These bikes are sweet...

 

[5twins]

Actually, the spec calls for that slight in-out movement of the plunger within the adjuster bolt but without it coming out past the end of it. It should move between flush with the outer face of of adjuster bolt to in a MM or 2. Take the cap nut off and take a look at it, you'll see what I mean. And do it while the bike idles and you'll really see what I mean.

To see movement in the plunger, the engine has to be turning over, either by hand or running at idle.

 

[G_YamTech_314]

Actually, the spec calls for that slight in-out movement of the plunger within the adjuster bolt but without it coming out past the end of it. It should move between flush with the outer face of of adjuster bolt to in a MM or 2. Take the cap nut off and take a look at it, you'll see what I mean. And do it while the bike idles and you'll really see what I mean.

Great to know! I'm curious to see how close I got it just by going hand tight, and an extra 1/4" turn with the wrench.

 

[G_YamTech_314]

Getting ready to order more parts. (I'll never get tired of that statement)

I'm trying really hard to determine the value of this MC housing... Is it rebuildable? Or am I better off replacing? I'm not sure the reservoir is any good... I know for a fact it needs new seals, and a new piston. the cyl. Itself is poor. Is there hopes of keeping it alive? Any tricks? Muriatic acid to bust up chunks? HELP lol

 

[ThatXS650Guy]

Single disk? If so, you might as well replace it with a smaller MC. Lot's of threads on here about that. Mine is Hugh's 12mm unit and it works great and it's a smaller/sleeker package.

 

[G_YamTech_314]

It is a single disk. I have the dual disc forks though, as well as the two hose splitter up front... Is it an issue to have a bigger M/C for a single disc? I'd imagine it just makes touchier brakes? I guess all of this depends on whether or not I can even salvage the m/c.

 

[Brassneck]

Single discs and that MC is what came stock on US built bikes, whereas Europe and Australia I believe had dual disc set up. The US stock MC is really better fit for dual discs, but it works fine for single discs...however, if you really want to improve your brakes, then getting a smaller bored MC will noticeably improve performance. That as well as SS braided lines. If you find your MC not repairable, might as well get a smaller bored option.

 

[G_YamTech_314]

Single discs and that MC is what came stock on US built bikes, whereas Europe and Australia I believe had dual disc set up. The US stock MC is really better fit for dual discs, but it works fine for single discs...however, if you really want to improve your brakes, then getting a smaller bored MC will noticeably improve performance. That as well as SS braided lines. If you find your MC not repairable, might as well get a smaller bored option.

Good to know. I read up a lot on the type of my I may have. Looks like someone took the entire front end off of a "special" and slapped it onto the '76 I own... The mc is definitely off of a special. As well as the buck horns. And the forks support dual disc as mentioned earlier... I've got some thinking to do when it comes to the front brake set up with this thing then... To keep the 2 hose set up? Or to just get one good single hose, and a new mc... Would a new/different mc be compatible with the caliper?? They don't teach this kind of stuff in formal motorsports technology education

 

[Brassneck]

I'm pretty sure all US XS650's came with the mounting holes for calipers on both forks....it's just that they only used the one side for US bikes.

If you're going to add a second caliper, then obviously sticking with the splitter makes sense. You can still get SS braided lines but you'll just have to get some that fit from the MC down to the splitter, and then one off of each to the calipers. Personally, I wouldn't add a second caliper, as I don't think it's necessary for the stopping power the single provides with the right sized MC and SS Braided line. Nor does the added weight help much-- I can't recall off hand, but the stock rotor/caliper is pretty heavy...and you'd be doubling it, which to me doesn't make sense. However, if you're going to go with dual calipers, then I would look at getting some performance brake rotor's (Mike's has them)...they're much lighter, look great and work very well. If you're sticking to the one disc set-up, then bypassing the splitter with one long brake line makes the most sense. Totally up to you though.

And Yep, pretty much all MC should work with the stock caliper's...assuming they are the right bore size.

 

[G_YamTech_314]

I'll have to measure the bore on it when I get the time .perhaps I'll rebuild it and just sell it! It doesn't hurt to gain a bit if scratch have to put towards a different mc.

 

[gggGary]

It's not intuitive, but; bigger MC bore gives less feel, the bigger piston increases volume of brake fluid moved but reduces the pressure multiplier ratio. A bigger MC will have you grabbing with all your strength, trying to get the damned bike to stop, not good. Some very good background info at vintage brakes Michael Morse' site.
As exhuastively reported a 10 to 12mm MC is about perfect for a single stock caliper. If an old MC needs parts then buying a new repop or used yamaha MC (TW200 ttr250) in that 10-12mm size is your better option, be careful many repops fail to mention the bore size, a 14mm is the most common size, that's stock and not ideal.. Not to mention most here toss the buckhorns, that angled "special" reservoir is far from perfect on the typical replacement handlebar....

 

[G_YamTech_314]

I never even thought about the angle on the reservoir. That's gonna need swapped for sure... I'm not keeping the buck horns, they worked just fine for my first ride but I can't stand the way they look. I figure I could get some cafe bars pretty easily. I'll be searching the classifieds for a good M/C later today at the Ol', 9-6 looking forward to having front brakes. The test ride was slow with only rears.

As far as the rest of the front end goes things are looking alright. Head bearings don't feel loose or crunchy at all. Pretty much wants to fall to either side on it's it' so that's a huge plus. Tires need replaced, as well as chain and sprockets. But first I wanna get the bike to stop... And then fix the signals, and try and find the adjusting screw and spring for the headlamp. I may or may not have misplaced it when I was trying to remove the headlight to rewire the ign. Switch. Oops ..

 

[gggGary]

It's personal but the older guys tend towards super bike or euro bend bars for the best ergo's and comfort while riding. Funny how we begin to value that over looks as we age

My favorite ride has dual disks, 14mm MC, euro bars on virago risers ( a bit up and back) Never mind the other old guy stuff you see on there. This bike got 5,000 miles on it last year.
There's an endless build thread about this bike "Madness" This pic alone shows 20 or 30 variations from a stock bike.