Not fun...definitely not fun...

So I've been riding my '82 XJ650R (Seca) since I got her a couple years ago. And I mean riding almost daily. I changed the oil, the plugs, front wheel bearings, etc. and in general maintained the bike. (I never did get around to replacing the jets yet because I keep missing carb auctions on E-Bay.) Hell I almost never went over 4500 RPMs with her.

Anyway on the way home today she started to give me problems. She started acting like she was arcing or something. I'd crank the throttle and she's bog until the RPMs came up. Not surprising to me at the time because I was riding in the rain.

The problem got worse the closer I got to home. What would happen would be that if I didn't have the engine RPMs cranked up the bike wouldn't move but once she got moving she was fine. In particular off the line I would have to really crank the throttle and then slooowly ease the clutch out or she'd completely bog. But the engine would run fine with the clutch pulled in or in neutral. It's only when the bike is under load.

I got her home finally and got her up on the center stand and spun the back tire and I can hear a distinct "clacking" noise as she spins that wasn't there before but I haven't pinned it down yet.

At this point I just don't know what to look for in diagnosing the problem and am looking for pointers. I really want...no I _need_ to get her fixed because I don't have another vehicle at the moment. A little help?

 

Is the clacking from the rear tire area or the engine area? Rear brakes hanging up?

 

are you running pods?

 

I don't know yet. I'm waiting for a call from my boss who's in Shanghai so I can fix his computer problem. Then I'll go back out and try and pinpoint the noise. At first hearing though it sounded a lot like it was near where the rear drive joins the trans output.

 

Yeah but they're pretty covered by the sidecovers so I don't think they took in any water but I might be wrong there.

Is it possible I took in enough water to be a problem?

 

well depends was it raining hard? Have you rode in the rain before? Did you have the problems then?

 

I'd ridden her in the rain before and not had any problems.

 

Look for water in the U-Joint Boot. That can fill-up if the drain hole underneath it is plugged with road grime or not ever opened new.

The clacking might be a U-Joint.
They make clacking noises like ringing a muffled bell. A soft dinging kind of noise muffles by the U-Joint Boot.

Put the Bike in gear and rock the rear wheel back and forth and "Listen" and "Feel" for it having too much play.

 

Well I had a moment to go out there in between waiting for other things and I did a couple of things:

1) Slowly turned the back wheel and using a screwdriver to my ear pinpointed that the sound I was hearing is in the final drive side of the wheel. I can hear a slight clicking in the area of the U-joint but it's fairly faint.

2) (You can tongue-lash me later for this one.) I started the bike and let it idle in first gear and the noise became more pronounced in the final drive area.

3) The screwdriver also gave me a sound like a whispering metal on metal at the engine housing just in front of the U-Joint boot. I'm hoping that doesn't mean spun bearing in the trans. :-(

I had to come back inside to handle something and might not be able to get back out there until late tonight or tomorrow.

I'm hoping that if anything major failed it's the final drive because those appear to not be all that expensive nor hard to install. I don't have the right oil to drain and check that part for metal shavings yet though.

 

My moneys on the U-Joint.
You have to abuse the bike to get the Final Drive to poop-out!

You haven't been doing a lot of Burn-out's ... have you?

 

Hell no. The bike is my daily transport. I've been babying the hell out of it.

Would the U-Joint cause the symptoms I've been experiencing? Is it more like a CV-joint in nature? I was always under the impression that true u-joints either work or don't.

 

A U joint is just a cross with a set of bearings at each point.
Bearings fail, get play.
A CV joint is like 2 U joints linked together, so the axel can pivot in multiple directions.

 

a u joint can almost be completely whored and still work. Would have a ton of lash though, but still work.

 

Well I did a couple more quick diagnostics and it feels like she's stuck in 4th or 5th even though she's telling me that she's shifting and feels like it from the lever.

I bit the bullet and have ordered the clutch basket/rings (just in case), the majority of the trans parts (E-Bay), and a rear drive with shaft (E-Bay).

I want to have anything and everything handy before I tear into her. (It cost me about $200 in parts total - not bad. I forgot to order the chain guide that everyone points out to replace but I'll order that the end of this week.)

Is there a good how-to on cracking the case? I've never done one before. Someone mentioned Yamabond? What is that and where do I get it? Will Chrysler grey transmission grade RTV work? I'm assuming a gasket is not needed? :?

 

We'll forgive you on the starter chain tensioner, just DON'T forget it.
Clean the outside of the engine throughly!
I used a sheet of cardboard with a silhouette of the case, poked holes where the bolts go and stuffed the removed fasteners in as I removed them.
You will need a few o-rings, source some viton types. One is for the oil pump and I forget where the other one was.
I used Permatex's MotoSeal® 1 Ultimate Gasket Maker Grey (it's at their website). Works great, inexpensive and I wanted to explore alternatives to Yamabond. I would wager that your Chrysler material would work just fine.
Be sure to install new seals on the crank and output shaft (if you can swing it), heck replace them all. And the case plug on the opposite case cover from the timing plate.
Oh yes, there is no case gasket.

 

Thanks for the info!

A couple more pesky questions though:

Am I going to have to take the motor out of the frame?

Am going to be messing at all with the timing/internals of the motor or is the trans a separate compartment?

I've got the XJCDs somewhere but have not seen them since the move. Will a Clymer or Haynes manual do for this job?

(I hate to keep bugging you guys with these questions but I don't know where to look for the answers...)

 

You should pop for the Factory Workshop Manual specific to your Bike.

The Factory Book has everything compartmentalized and provides good "Play-by-play" for getting in there and getting things done.

http://www.yamahapubs.com/html/year.jsp?type=MC

 

Hmm...$79+shipping. Cool. End of the week then. That means provided I've got everything I'll likely work on her next week some time.

It's funny. At this point I've spent more than half of what I paid for the bike but have no intention of getting rid of it partly because I like it and partly because it's my first ride. I've heard so many sad stories from guys who regret getting rid of their first bike...

 

With the exception of the Main Fuse Panel and the Headset Ball Bearings; these XJ-Bikes are, as the MotorCycling Press stated in the second year Bike Review:

"Hard to Kill"

Once you get the Experience to be able to remove and CLEAN the Carbs, then learn how to do some Tuning ... a wonderful relationship develops between you and your Bike.

When you gain the experience to be able to do the several chores necessary to put the Bike on the razors-edge of Fine-tuning.
You really fall in love with the thing and WANT it to last forever!

 

I'll not disagree with any of this. I only wish I had the cash to do the jets now so I can get the majority of it all done at once and concentrate on dress-up. :-/

I got the rear drive and shaft in the mail today and so far the parts I'm still waiting on, besides the last things I haven't ordered, are the clutch basket+rings and the transmission parts.

I was half tempted to just wait until I have all the parts and make it a fall project but then I remember how much gas is costing me in the meantime...

That and the fact that I gain a _lot_ from riding every day.

Umm...Headset Ball Bearings??