Complete XJ650 Rebuild

Hey everyone,
Looking for a lot of guidance on my first rebuild. I have been combing through these forums and anything else I can find on my bike preparing for a complete overhaul of a bike I bought just over a year ago.

To give you a little back-ground on this... This is my first bike, I have ridden a little bit when I was younger on dirt bikes, etc. I have never rode a road bike and was very interested in learning about motorcycles. If anything this is more of a challenge for me as I am the type of person that like to understand things by tearing it apart and learning that way.

Like I said I bought this bike awhile ago and it was in a sad state. It was left in an alley for a couple years, knocked over and left for dead. I bought it for $250, moved it to my house and a friend of mine rode it around to let me know if anything was majorly wrong. It started fine but slipped in 2nd and that is all I know about it.

I started taking things apart to clean, change out, and again trying to understand. I am looking to give this bike a bit more of a cafe / brat style look but that is not why I am starting this thread quite yet. Over the past year I have torn down almost every single nut and bolt of this bike, found some pretty unfortunate things along the way and even possibly did somethings I shouldn't have (now knowing, I won't be making those mistakes again).

While I was doing that I also built my own sand blasting booth and powder coating oven. I told you I like to do everything myself and if it requires me making something to do it, I will.

I have attached some pictures of what I have done so far (it was all I grabbed along the way but will be taking much more as I put things back together).

My main goal for this thread is I am going to need some help with assembling my engine back together, information I need that I haven't really found in other threads or diagrams, maybe other ideas for my bike I haven't approached yet, and just somewhere to share my experiences with other people.

With that said, attached are some pictures. One of my frame chopped for a new seat. My first powder coating experience on my rims (which turned out pretty good I think). One of the problems I found getting into my engine. Some randoms.
I will have my first questions later today and maybe a few more pictures.

 

Back end of my frame, loop was made for the seat I purchased about 6 months ago.

 

Yikes, that gear is a mess. Good project, I'm also building a 650 from the ground up but I didn't need as much engine work.

 

Yea that gear is what I found when I got the cases apart. I also found this which I believe was why the 2nd gear was slipping:/
Taking the whole engine apart might not of been the best thing for me to do being my first bike but after finding this I am kinda glad I did.

 

Well with that kind of repair, you have to split it anyway. I was on the fence with mine when the motor was out/head torn down, the chain guides are not broke but they all break at some point. It'll be worth it, you can replace those chain guides too and be done with it, shouldn't have to split again for a long time.

 

I have an XJ650 Seca I've parted out. Let me know if there are any parts you could use.

 

Did you also happen to find that the alternator chain guide was broken? A broken shifting fork is really uncommon; I don't think I've heard of one failing (aside from being bent) without something else letting loose first.

 

K-Moe, to be honest I am not 100% sure.
I started tearing this apart months ago (stopped for a while to finish building my oven) so I have part both at my shop and my house. When I get everything back in one spot I will let you know.

 

BTW, your powder coating work looks great! I'm about to send another batch of parts off to be coated. Wish I had the room at home for a small setup, it's addicting.

 

My God, some riders are rough with their bikes !

I just bought an XJ900 with the same slipping 2nd gear issue, I'm anxious to see what I'll find in there.

 

OK. Even if the guide isn't broken it is good insurance to replace it, and to rebuild the starter clutch while the engine is apart.

 

Hopefully it's just the more common worn dogs (or even better; a slipping clutch).

 

Yeah, knock on wood.

 

Updated picture of some coating I did tonight. Both bottom cases done, Top halves later this weekend. Will be needing the help as I start putting the cases back together.
I found a thread on rebuilding the starter clutch with the bottom cases together but nothing about it where I am at the stage I am.

 

The starter clutch can't be rebuilt with the cases together (without cutting a window in your cases; not advised). That rumor was debunked a long time ago.

You already have the starter clutch out, so rebuilding it is as simple as ordering a set of springs and rollers from Chacal (along with a new alternator chain guide. Reusing the old one is inviting disaster).

 

Welcome aboard. You're at the right spot for all things XJ.

Gary H.

 

Alright some updates.

I might not have mentioned before but I am coating a case I bought since the original case that was on my engine had a large crack in the bottom half. My plan was to tear the original engine apart, add in this "newer" case and hopefully keep all the internals (excluding the bad parts I found like gears with the broken teeth and shifter fork.)

So tonight I finished coating everything and got the parts out of the upper case. The chain guide I found was in one piece when I took it out but as I laid it down for the picture, you can see it split into 2 pieces. There was a crack in it and it just fell apart in my hand.

I am getting all the nessisary rebuild kits from Chacal but I can't seem to find that guide anywhere? (most likely because I don't know what it is called outside of it being a guide)

On top of that I have a question about bearings. Is it possible to "rejuvenate" bearings I am pulling out of the internal engine? I am talking about the ones that are on the end of gear shafts, around the starter clutch, etc.?
Sorry if my terminology is confusing or incorrect, I am learning as the days go by.
The bearings I am talking about are ones without rubber seals (something you would find on a wheel bearing) on both sides but the ones where I can see the balls and the other ones that have the little rods.

A lot of the parts I am pulling out of my original case obviously are covered in oil but are very grimy and I can feel dirt or whatever on them (probably metal shards from the broken parts). I believe I can clean a lot of the solid pieces like gears, shafts, etc. but not sure how to deal with the bearings.
Is it as simple as washing all the parts with mineral spirits or whatnot and re-lubricating them?

 

You can't rejuvinate bearings. If they are smooth, and have no gouges you can re-use them though (after confirming clearances with plastigauge during a dry fit-up).

Here is the tricky bit: you have to figure out which bearings you need to match the replacement cases to the crankshaft. You can't just swap the cases or you'll not have the correct clearances to maintain an oil film at the crankshaft journals, and you should avoid just swapping one half of a set of cases since the halves were machined as a pair when new (it can be done, but takes a bit more work as you will have to measure the bearing journals in the replaement case-half and do a fair amount of math since Yamaha only gives us colors for bearing sizes, and not actual measurements).

The bearings are color-coded (you'll see a bit of paint on one of the side edges), the crankshaft end has a set of numbers on it, and the upper case has another set engraved into it (location varies, but usually near the output shaft). Together these numbers let you determine what bearings you already have, and which ones you will need (There is a writeup on this in the XJ4Ever catalog).

Here's the real issue: Finding bearings at a reasonable cost if you happen to be unlucky and not already have what you need. 10 bearings at around $20- $30 each (if you can find them in the colors you need) is going to be spendy (assuming that you need all 10). I went through that process last year, and got lucky; I was able to use a mix of the bearings in the replacement case, and the bearings in the damaged case that I already had.

Here is what I would do.

Take the lower case to your local machine shop and have the crack welded shut (thoroughly clean and degrease the case and the crack yourself to reduce the cost of the repair). It should cost you around $100, and the estimate will be free.
I would have used this option myself, but I was extremely cash-poor at the time, and found a set of used cases for $40 shipped (hugely lucky; did I mention how lucky I was?)

The bearings might be OK. Flush them out with the solvent of your choice WITHOUT letting the bearings spin. Use a light oil to lubricate them, and then rotate them slowly by hand. If any bearing is not buttery smooth, then chuck it and buy a brand-new one (there is one bearing that is nto available new from Yamaha (I forget which one it is), but a bearing supplier might be able to make you one if they have a decent amont of stock on hand; just take it in t them), otherwise you'll need a good used one.

 

Good thing you found out about that chain guide NOW, rather than later!

Here they are:

HCP7551 OEM starter primary chain plastic GUIDE, for all XJ650, XJ700, XJ750, and XJ900RK, RL, N/FN, and F models. NOTE: some original versions of this guide used three mounting bolt "tabs" (and required 3 mounting bolts). This replacement versions only uses two mounting tabs, and thus two mounting bolts (one at each end).
$

HCP4791 OEM starter primary chain plastic guide RETAINING BOLT, use 3 per guide, for all XJ550, FJ600, XJ650, XJ700, XJ750, and XJ900RK, RL, N/FN, and F models. NOTE: some original versions of the guide may have had three mounting bolt "tabs" (and required 3 mounting bolts). The replacement HCP7551 Guide only uses two mounting tabs, and thus only two of these mounting bolts are required. Each:
$

HCP10233 OEM starter chain and guide oil spray nozzle O-RING, use 1 per engine an all XJ650, XJ700, XJ750, and all XJ900RK, RL, N/FN, and F engines.
$

 

Alright I need to step back because I think my terminology screwing up what I am understanding.
I have two complete upper and lower cases. The dirty one is the original and the painted one is "new".


This is the crack I was talking about and I don't know where the missing piece is (not sure if that could be welded anyway)


Next, when I am asking about bearings I am talking about these.

These are the same bearing that came from inside of the Upper Cases.
The top one is from the "new" and the bottom is the original.
I believe this on the end of the Stater Clutch. It came from here.

I was asking if these bearing are able to be cleaned and "re-juvinated". The bottom one has a ton of dirt in it.

Next I have pictures of the Crankshaft # (21222 1212 is what I read, picture is hard to see)