Blew my TRANSMISSION!!! ?

For my 1982 xj650 seca

I was giving her in 4th yesterday (120 km/h) on my inline four. All of the sudden I couldn't shift up into 5th. By the time I got to Banff (20 k) I couldn't shift up at all. I down-shifted it to second and there it stayed. Trying to get it into neutral after I'd stopped the bike, I accidentally put it into first and now I can't start it.

Any suggestions as to where I should start? Id didn't sound like gears were grinding, it just didn't want to shift up. It had no problems shifting down. It's a wet clutch. Cold day. Engine had warmed. First time I really opened it up on the highway and I'd driven it for weeks around town. There was also an unrelated mixture problem. I may have been running 10 w 40 as opposed to 20 w 40, but it shouldn't have mattered after the engine had warmed, right?

Any ideas?

Aaron

Again, thanks everyone for your help. This is the best site ever.

 

Starter chain GUIDE has most probably started puking pieces into the engine (it's hard rubber, and disintegrates over time), and one or more of those pieces has gotten stuck in the shifter drum, preventing shifting.

First step is to do a search for "shifter drum" on this website and you'll find out the removal-of-the-rubber-chunks procedure.........

Then, you'll have to decide whether you want to replace that chain guide, as it requires a bit of major surgery.

 

+1 On what Chacal said.

 

Chain guide... the thing I see in the middle when I lift the valve cover? Can I check to see if that's intact before I go crazy?

 

No, that's your camchain. Chain guide they're referring to can't be seen without taking the motor apart (although chunks of it can be found; see the referenced posts.) The chain guide that breaks up is for the Hi-Vo chain that drives the alternator jackshaft.

From your symptoms, however, you may simply have a broken return spring on the shifter pawl or one side of the over-center spring.

If the centering spring and the pawl springs are ok THEN you need to start looking for chunks of the chain guide.

 

No, wrong end of the engine, and wrong chain!

The starter chain runs from the crankshaft to the alternator shaft, and there is a "toothed" rubber "guide" that puts tension on this chain and prevents it from flopping around. If you look on the rear side of your cylinder jugs, and find the CAM chain tensioner unit, look directly below that and you'll see a bolt head sticking straight up out of the upper engine case. Although that bolt is also a CAM guide tensioner, the STARTER chain and it's guide live directly under that bolt, too.....just so you can get an idea of "where" inside the engine we are talking about.

The STARTER chain and it's guide run horizontally (kinda) within the engine case, whereas the CAM chain runs vertical.

 

Thanks guys.

Can you please point out the problem areas on one of these pictures?

Using your best judgment, do you think I'll just have to fish out the plastic or replace the part?

 

How the heck do I attach this diagram?

 

Here it is.

 

Oh for the love of...

Go to

http://www.xj650.de/manual/thumbnails/x ... wings.html

Click on

D11.gif
248.45 KB

 

Here's the procedure:

1. Buy a small claw-picker from your auto parts store.
2. Remove the left gear box cover. You will see 2-3 holes the size of a half-dollar.
3. Use a flashlight and the picker to dig any black, rubber pieces out that you see lying inside the holes. Usually the front, lower hole.

That will fix you for now. I had to do the same thing. The sad answer is, our engines are ticking time bombs. One day, the chain guide will totally fail and if we're running at high speed, the engine will grenade itself.

The only cure is to replace the chain guide and so far, the only way to do that is to remove the engine and split the case. We are currently looking for a way to snake into the bottom through the oil sump, remove the old one and bolt in a new one.

 

Thanks all and once again to chacal, bigfitz and sushi_biker.

I have a detached maxim 650 engine. Is it the same centering spring and powel spring as the seca? Is the chain guide the same? Could I fish them out of my old engine if need be?

 

The parts would swap between your Seca and the Maxim engine. However, for the amount of effort to do this, you are better served installing a new guide (the old one would be another time bomb waiting to fail). Spring the $30 and buy peace of mind.

 

I'm not really sure about this one. I mean that those bikes are ticking time bombs. Here's why. When a piece of chain guide falls onto the selector drum it's likely that during a shift you're engaging two gears instead of one. Of course - because of the different gear ratios - the transmission locks itself along with the rear wheel. The result: a nice slide I did it when I was about to cross a road. I accelerated 3 meters then put into second, wheel locked and I slid 2 meters and was on the middle of the opposite lane trying to push the bike somehow down from the road.

But that's not important, back to the explanation The problem is that the selector drum selects two different gears and that locks the transmission. But selecting two different gears is possible only (with the amount of force what our legs are able to produce) when the gears are rotating slowly. I'm assuming it won't be possible to engage two gears at a time over 40 miles / hour. But to be honest, I think the actual limit is less than that. Maybe 20 miles / hour? (you can try to shift on a manual car without a clutch. It's not possible when the difference between the engine shaft's speed and the wheel shaft's speed is more than 10%)

On top of this, when I checked the guide I realized that the parts fall from the middle of the guide. So, the chain is actually grinding the guide instead of breaking it. Which is not really good for the engine but I can live with that. However, I'm always a bit scary when I feel the transmission is not engaging the gears properly

 

Hi there,I've recently finished my 650 seca resto and found a big chunk in the sump. Luckily I got a low mileage mill to swap in. I did open up the new one just to be sure though. Anyway I bought a new guide and cam chain and clutch plates b4 I found other mill. if you'd like any of them let me know. I also have the complete original engine completely apart.Guzzi John-Champlin,Mn :wink:

 

From your link look at C09 part no. 23 this is the chain guide.
Look into the return spring as Fitz said and keep your fingers crossed.

 

Yep, it was the chain guide. I pulled three big chunks out and had to remove the oil pan to get them.

Which brings me to my next problem...

See my next post on BACKFIRING

KaPOW!