Dreaded Cam Chain Guide

[Jan_P]

Short comments
everyone makes bad deals when it comes to old bikes sometimes and Cars and other things.
Even if you have done it for many years there is eventually a bike where you missed something at the purchase.
Not everyone will admit it .but that's the way it is .

As mentioned I had one Piston looking like that little less damage .. I got away with honing ( Perhaps you wont )
.. The top is off so inspection of top end is possible and feeling the play in the small end conrod. and so on
I did not open the bottom .Of Course inspection for particles in the low filter --- magnet ..and oil pump working

I replaced the Cam shaft bearings .. I do that when I am in there had some on the borderline to explode.
Normal head job .. valves ..inspecting the cam and so on Valve stem seals.

The Crank bearngs are solid and a lot of what is coming loose shavings and so is aluminium so maybe they can take it

Note this is not a recommendation this is how I did it
are bore here is expensive and I am the " last owner " segment so this above described method is not suitable for a mint machine.
I feel that these bikes runs well even without perfect Compression.
As mentioned new set Cylinders and Pistons or another engine perhaps

 

[arcticXS]

Inspired by this thread, I sent an email to Gary yesterday, placing an order for 2 guides, and received his reply only a few hours later (I was in the CET timezone), and also a PayPal request/ invoice, which I approved a couple of hours ago. Again I got a prompt email response from Gary, with tracking info. This is above and beyond any customer service I have ever experienced! I have to give my strongest recommends for Hoos Racing/ Gary Hoos and his services!

 

[gggGary]

Inspired by this thread, I sent an email to Gary yesterday, placing an order for 2 guides, and received his reply only a few hours later (I was in the CET timezone), and also a PayPal request/ invoice, which I approved a couple of hours ago. Again I got a prompt email response from Gary, with tracking info. This is above and beyond any customer service I have ever experienced! I have to give my strongest recommends for Hoos Racing/ Gary Good and his services!

Hoos is good guy! Just ignore the retiring soon stuff. He says that on about 3 year intervals, then in a couple months he's back at it. ;^)

 

[Britman]

Depending on what a set of used stock bore jugs and pistons look like when they arrive next week, looks like I am going for a top end rebuild. The set is supposedly from a bike with 4k on the clock and pictures look good and the price was low enough it was worth taking a shot. If they are within spec I will be ordering a cam chain, guide, rings, and gasket set and will probably use Hoos for the majority of it.

I do have a question about the head sealing washers. When I pulled my head I found the PO had installed the rubber based washers under the center four 10 mm dome nuts. On the outside four corner 10mm domes he had metal washers only installed, which is totally opposite of the correct layout as I understand it. I see where some are running all copper and others just replace the outside rubber with copper and retain the metal on the inside. I could not really find what is the recommended specs for the four 8mm bolts in the center of the head also, two of mine have a detached washer and two have a flair head and no washer???????

While I am waiting on parts, looking at video's and going through my Yamaha XS650 shop manual I recently found buried in my library I also stole 5Twins idea and made a tool for setting the piston circlips with pistons in the jugs without having to bring the Wife in for an extra set of hands, that would be just trouble. I am also going to spend some time getting everything cleaned as much as possible. Head has been decoked and a leak down test done with good results. Wish me luck Gentlemen......

 

[Jan_P]

Does not say .here but if to little oil was the cause A check of valves movement ..perhaps is something to consider.
A lapping ?
+ Inspect cam surface and piston tops. Not having contact marks .

 

[Jim]

Nice homemade tool. There's various ways of doin' it, but I've found 4 pieces of 4" wood and duct tape are about as simple as you can get for holding the jugs in position.

From here....
https://www.xs650.com/threads/xs650-top-end-buildup.52041/

 

[Wingedwheel]

I do have a question about the head sealing washers. When I pulled my head I found the PO had installed the rubber based washers under the center four 10 mm dome nuts. On the outside four corner 10mm domes he had metal washers only installed, which is totally opposite of the correct layout as I understand it. I see where some are running all copper and others just replace the outside rubber with copper and retain the metal on the inside. I could not really find what is the recommended specs for the four 8mm bolts in the center of the head also, two of mine have a detached washer and two have a flair head and no washer???????

4) 90210-10004 - 10.9x22x2 (Outside head nut) (Suzuki 09168-10017 10.5x22x2) Copy and pasted from Tech.
Normally just the outside 4. The steel washers for the inners have always worked just fine.

 

[jpdevol]

I do have a question about the head sealing washers. When I pulled my head I found the PO had installed the rubber based washers under the center four 10 mm dome nuts. On the outside four corner 10mm domes he had metal washers only installed, which is totally opposite of the correct layout as I understand it. I see where some are running all copper and others just replace the outside rubber with copper and retain the metal on the inside. I could not really find what is the recommended specs for the four 8mm bolts in the center of the head also, two of mine have a detached washer and two have a flair head and no washer???????

On the 10mm sealing washers, I've been using these with good results; they hold good torque and they're perty (albeit pricy):
https://www.mikesxs.net/yamaha-xs650-brass-cylinder-head-washer-oem-90210-10004-00.html

On the 8mm, I use copper sealing washers - whether needed or not - even with flange bolts (I've converted to allen cap screws).

 

[46th Georgia]

Inspired by this thread, I sent an email to Gary yesterday, placing an order for 2 guides, and received his reply only a few hours later (I was in the CET timezone), and also a PayPal request/ invoice, which I approved a couple of hours ago. Again I got a prompt email response from Gary, with tracking info. This is above and beyond any customer service I have ever experienced! I have to give my strongest recommends for Hoos Racing/ Gary Hoos and his services!

Gary is awesome!

 

[Britman]

That motor is a piece of jewelry.....Beautiful......

 

[5twins]

Yes, only the 4 outside large acorn nuts require a sealing washer of some type because they flow some oil (drain oil from the top end back to the bottom end). The 4 inner acorn nuts and the 4 8mm bolts don't have any oil flowing under them so plain steel washers are fine for them. That's what the factory used there. I use copper washers under the outside 4 acorns .....

 

[Jim]

4 outside large acorn nuts require a sealing washer of some type because they flow some oil (drain oil from the top end back to the bottom end).

The XS uses a low pressure oiling system, so this really doesn't make a whole lot of difference, but the outer 4 studs get pressurized oil, not the return oil.
Oil (pressurized) from the pump goes up the external oil tube and splits out to the banjo fittings on each side of the rocker box. Passageways are drilled fore and aft to the rocker shaft cavities. These cavities, along with the rocker shaft's themselves are where the oil is forced out of the rocker so it splashes on the cam lobes.
These cavities pass through the stud holes on the outer 4 studs. The bottom is sealed with a sleeve and o-ring where the box mates to the head. The top is sealed with the washer just under the acorn (crown) nut.
The oil pressure is in single digits at this point... so very little difference 'tween it and the return oil. Still, my OCD forces me to point out it's pressurized oil.

 

[Britman]

Nothing with this bike has been simple, I am still on the fence about just saving it as a parts bike or trying to bring it back with the least amount of cost feasible. I am attaching a couple of shots of the low mileage stock bore jugs I bought. One side was absolutely pristine and the other, well can you say "sitting with rust in the chamber" for a long while. I have honed as much as I dare and most of the stain has dissipated, I can just barely feel one small spot with my fingertip, but no hanging on my fingernail. I have sent the shots to a good friend who has done countless vintage Triumphs, his suggestion is to go with it, and maybe go one size about standard on the rings and file for a good fit. I am the type of individual that likes to address a problem immediately, I don't even know how to spell "procrastinate" Siri told me. I am going to compile a parts list, to include new pistons, the ones that came with the cylinders had frozen rings I barely could remove and I actually damaged one in the process. If I decide to rebuild I will attempt to purchase what I need as reasonable as possible, and even then I know I will totally upside down on this bike if it comes to resale. There is another part of me that says don't let the "Demon Bike" win, jump in, enjoy the process, and go for it. Within the next 48 hours I will have either ordered parts or gone to Wally World to buy a couple of big plastic tubs to start the total disassembly.......

 

[Jim]

a good friend who has done countless vintage Triumphs, his suggestion is to go with it

For just a general runaround street bike, I'd agree... use 'em.
That is, provided they mic in limits after the hone.

 

[Britman]

Parts on order-Too late to turn back now.....

 

[Vincenthdfan]

Parts on order-Too late to turn back now.....

Been there, done that...know that "committed" feeling.

 

[Britman]

I haven't asked a dumb question so far this week and now my hand is in the air. If one was so inclined to order one size over standard bore ring size to do a little filing to get a tighter ring gap what would be the next size up over standard to accomplish that task? I am within spec but nothing to write home to Mom about and I really don't want to order a set too big. Any suggestions also on vendor priced within reason and would have them on hand.

 

[jpdevol]

.25mm over is considered "1st over"....75mm is nominal std. bore size, so 75.25mm

 

[Jim]

Using oversize rings and then grinding them down to the optimal gap is a standard hot rodders trick. If your bores are still within spec, you'll be doing some gap trimming even for the .25 overs. Fwiw, even .5 or 1mm overs will work just fine also. It'll just mean more filing to get the right gap.
They make a special tool for gapping rings. They're a little spendy for just us part time users. I've always just used a 1/16" cutoff wheel in a die grinder. Makes quick work of it.

 

[5twins]

After breaking one while hand filing, I bought the special tool, lol .....

Yes, at around $40, the tool is a little spendy, but you've got 8 rings to do (2 regular and 2 oil rails per cylinder), so that works out to only about $5 per ring. Do another set some day and you're down to $2.50 per ring. Do enough of them and the cost per ring will get down to practically nothing. I recommend trying to get the .25 1st over-size. Even they will overlap at the ends when 1st fitted and require quite a bit of filing.