1982 XJ650RJ Seca Cylinder Base Gasket/Piston Ring job

I used baby powder to verify that, indeed, I have an oil leak at the cylinder base gasket tight at the location of a broken cooling fin. I suspect I knocked something over in the garage into it breaking the fin and hitting the gasket somehow? It's a pretty significant leak, so since I will have to disassemble this far, I did a compression test showing low compression on #'s 2 and 3, with a significant improvement wet, so I'll be changing rings while at it. my questions:

1 What should I make sure I do while I dig in this far? Chain guide?

2 How much farther would I have to dig to get to the starter clutch? I don't want to mess with crank bearings etc., so I am assuming splitting the cases is more than I want to do, but could I split them and do the starter clutch without that much more work? I rebuilt the starter last year and it has made the starter connect 80% better but sometimes it still just spins.

 

Splitting the case is actually pretty easy see my thread on the "Dreaded starter clutch" I have pictures , and directions. Once you remove engine , and flip over it is just a matter of removing bolts, and clutch cover, left side cover ,oil sump , the alternator rotor , I bought an overhaul kit from England very good quality kit .




































































































































































































































Attached picture is a stater clutch























I used a wooden palate this worked great to keep from marring the engine cases . I've done two starter clutches now and helped via phone Mr Seca do his xj900 ....On his the starter clutch was cracked . Attached

 

Thank you!

 

Well I screwed that post up! Here is what I was trying to say:


In your thread there is considerable discussion about the chain guide. Is this referring to the primary chain guide? In some earlier correspondence with my bikes previous to previous owner (I lucked into finding him on Facebook) he says he replaced that in 2016. Or is it the chain guide for the cam chain?

 

OK, I've been perusing this, and still don't quite understand. Do I have to split the cases to get to the Starter Clutch? Or are you saying I can get to it through where the alternator rotor is?

 

You have to split the cases to get to the starter clutch.

 

Here is a picture of inside engine the starter clutch is on left and has the large chain on it.

 

Thanks!

 

Not to speak out my butt as I've not worked on 650. The repairs you need to do can be done in frame. The repairs you want to do require removing engine. I wouldn't say it's hard all things are just time. So the question for you is do you want to pull engine or not?

 

Engine is out, cylinder is honed and ready for new piston rings. Starter clutch works fine most of the time and I am freaked out and worried I'll do more harm than good by splitting the cases, and am leaning towards reassembling and keeping the oil changed and up, as that seems to make a difference on the starter clutch. I had a leak at the cylinder base gasket which is what prompted the whole process.

 

Time and money now or possibly more time and money later? You are halfway there. That's the issue. You might not get problems with the parts inside the crankcase. Most important thing is working methodically making bolt templates out of cardboard and numbering them for the case bolts. It's not difficult if you decide to split the cases just post questions as you go and take loads of photographs.

 

Here is @Mezzmo video from his build on engine reassembly.

 

Ugh, y'all are so supportive where do I find more excuses! I guess, I'll have to do it! Just anxious to get it out and ride. It's a beautiful day!

 

Just noticed you're in Fargo! I'm in Minneapolis, and my daughter will be starting at NDSU this fall.

 

I also went to ndsu. Small world

 

Anyone else have difficulty with the clutch center nut? I bent the tabs out, and have a flat piece of steel with some bolts to hold the drive shaft flange from turning, but when I try to turn the nut, there is a whole lot of give in the transmission (it feels like) and that makes me worried about doing damage with all that torque. That said, I don't think I can match the torque of the engine, but it doesn't normally have the driveshaft immobilized, either.

 

Neighbor's impact driver to the rescue. Gotta get me one of those!

 

If you can just borrow one then you’re good!!

but the little cordless impacts are really nice to have.

a monster 1/2 drive is nice to have too. Just not needed as frequently

 

Aren’t there supposed to be a pair of these half moon circlips at each of these four locations in the picture? (please excuse the double line on the one arrow).

I only have them in the upper case, they are in position in the main pic. Second pic is one of them in case my terminology is incorrect.

 

No you have one in each bearing and fit them so they bridge the cases.

The shim on the right looks like it fits behind the bevel gear for the drive shaft.

 

Thanks! I didn't know that I should swing it up to align the lower case half, makes sense though! I appreciate the confirmation.

 

Getting ready to put the cases back together. Do I loctite the bolts? Red or blue?

 

No loctite just torque them to spec.

 

I have Loctite 515 ready to go, but it looks like I need to get Loctite Klean ‘n Prime. Is that necessary??

 

Crossposted to the FB groups.

Yamaha XJ650RJ (Seca)

Doh! I’ve spent the entire riding season rebuilding my engine (it’s hard to find time) and I forgot to order these oil seals (between the cylinders and the head). I really want to get on the road. They seem pliable and not torn. On the other hand I’d hate to plop down another $90 for a head gasket if the seals leak. Haynes manual says, in bold, put in new o rings, but they are seals, not o rings. I’m sure Len could get them to me by the end of the week, but I really wanted to get it in the bike by then.

Any thoughts on how critical these seals are? I think I know the answer but what do you think?

 

Ok. I’ve come to my senses and realized it makes no sense to not put new ones in.

 

So I’m thinking this tachometer drive gear should spin freely….

 

Yes, it should.

 

Reinstalling the engine and reconnecting stuff like foot pegs. This does not seem right as the kickstand won’t allow the peg to swivel back. Did I align the peg incorrectly? It lines up with the RH one.

 

Now that I look at the kick stand, it looks like maybe the kickstand lever is bent.

 

It could be the problem, should stick out more when up.

 

All together, and following the recommended break in process as posted by, I believe, Chacal. I have done the initial 15 minute idle, and the first two 15 minute rides with no lugging of the engine. One more 15 minute ride and change the oil and filter.

Cylinder #4 is running about 100 degrees cooler than the other three, per my meat thermometer (I washed it). Plugs 1 & 4 were clean. Plugs 2&3 had black soot. On ride 2 I switched the #1 and #4 plug wires, and the #3 and #4 plugs, and the problem stayed on #4, so not an ignition issue.

Carb # 2 is leaking out the boot to airbox, does not appear to be getting down to the crankcase per oil level and smell. Turned off petcock immediately and tapped the bowl and it stopped leaking. Must have dried out the needle valve tips while sitting in a box all summer.

Also getting some manifold smoke but I am terrified of breaking an exhaust stud. I guess I will loosen the exhaust mounts and joints and push the headers on more tightly and torque them down a little tighter.

I am guessing I have a carb problem leading to the cold cylinder, per the leak and the preponderance of discussion and wisdom on cold cylinders here on the forum. Should I do my next 15 minute ride tomorrow and change the oil, or should I really wait to address the fueling issue first? I have my fuel rail D rings and throttle shaft seals ready to go, thanks to Chacal.