82 XJ650 - Top tips on replacing the primary chain guide?

My primary chain guide broke and left me stuck in first gear last week. I pulled the offending piece out through the left side cover when I got home as a temporary fix. I plan to replace the chain guide but this is the first time I've split an I4. I have both the factory and haynes manuals and am mechanically adept. Do you guys have any top tips on this process?

 

Welcome to the site !!

The usual advise is to do the head since it's off, new rings wouldn't hurt, buy new shifter springs, (they're cheap) examine or replace the starter clutch, and the motors look awesome if you soda-blast them while out of the frame. The timing chain only lasts to 60,xxx miles too.

What part of Florida ??

 

Take plenty of pictures

http://www.xjbikes.com/Forums/viewtopic ... art=0.html

 

" The usual advise is to do the head since it's off,"
Why take the head off ?

 

Re: 82 XJ650 - Top tips on replacing the primary chain guide

@TIMEtoRIDE: I'm planning on flipping the engine and only splitting the bottom half of the case. I'm looking at a budget fix here instead of a full refresh. I'm near Ocala.

@adrian1: Affirmative.

 

there's 3 torx screws with peened heads in there that are tight, you need a hand impact driver and sometimes need to drill the peen out. blue loktite puts them back.
keep track of the shims where the drive shaft comes out.
extra hands help the shift forks go in easier.
you can grind a wee bit off the new guide to help it squeeze in, you'll see.
new guide 2 bolts, old guide 3 bolts. at least mine did, it's no problem.
there's something about the oil pump chain that gave me grief but i don't remember what it was.
you will have the clutch out, even if the plates look good the springs are old and weak, hint.
use yamabond or hondabond on the cases, rtv don't get it.

 

When I was reassembling my cases I found the hardest part was making sure the chain guide tension plunger stayed seated. Everytime I tried to get the cases lined up, I'd hear a pop and that sucker would fall out. I used an 18 inch aluminum ruler to hold it in it's seat until the cases were lined up, then slid the ruler out and bam, everything lined up and closed nicely.

 

Re: 82 XJ650 - Top tips on replacing the primary chain guide

I finished case reassembly today. Here are the top tips that I wish I had known before starting:

1. You will need a M16x1.5 bolt to pop the alternator rotor off its shaft. I used a bolt that was 40mm long but anything above 25mm should work.

2. If the case has never been split before then you will have to put some serious muscle on it. There are no undocumented secret bolts or anything like that, just really old yamabond.

3. When inserting the new chain guide you will need to cut a small part of one of the bottom lobes off in order to avoid disassembling the top end. The lobe is the especially large last one on the crankshaft end. It still won't be easy to get in but can be done without damaging anything. I don't think the cut will cause any long term problems since it's on the side facing away from the chain and is right next to the bolt for support.

@PilotSmack: That must be unique to the 550 as I don't recall seeing what you describe.

 

The hydraulic primary tensioner is indeed unique to the 550/600s.