The new life of a 72' XS II - Build thread

[Heinz Ketchup]

I’ve been riding every now and then, a few weeks ago I rode the bike out to the woods to collect mushrooms , which proved unsuccessful but I had a blast riding though:

Forrest ride

 

[Heinz Ketchup]

Playing with ai to generate versions of the Xs, based off a drawing I made years ago.

 

[KendenupXS]

Sorry for the stupid question, but what do you use to do an AI design of your bike, is there an app, software or some other platform available ?

 

[Heinz Ketchup]

Sorry for the stupid question, but what do you use to do an AI design of your bike, is there an app, software or some other platform available ?

Not stupid at all, the sketch is obviously just pen and paper, but the platform accepts most inputs, I just took a picture with my phone and used the website Vizcom.

The platform is free, you just need to upload a picture and write a prompt of what you want it to generate, for example a simple one;

“vintage motorcycle, with a few red details, in the mountains with sun in the corner”,

you can get more specific.

 

[Heinz Ketchup]

And then a new sketch of how the bike actually ended up looking, I probably won’t use ai on this one though.
Alabu being the original Viking name for the city I currently live in, Aalborg.

 

[willis]

I always liked this rendition. Not sure who made it, I just found on the interwebs.

 

[Heinz Ketchup]

Head’s off, quite a bit build up:

there’s a little play between the valve and the valve guide, we’re looking at 7.75-7.91 when it should be 7.975+, but it seems excessive that there should come as much oil through here as exit the exhaust. I wonder if the rings could be worn already, they’ve only been in for 2-3000 km..


I’m going to have to replace all the valves, as they are all out of specs in regards to stem size.. and I guess that means replacing valve guides as well, I’ll have to measure.
I just need to figure out if the oil could be coming from somewhere else, along with oil coming from the valves, I also noticed that all the valve seals, except for one, had already popped off the valveGuide.

 

[Its been a long time]

Head’s off, quite a bit build up:
View attachment 260135View attachment 260137View attachment 260136
there’s a little play between the valve and the valve guide, we’re looking at 7.75-7.91 when it should be 7.975+, but it seems excessive that there should come as much oil through here as exit the exhaust. I wonder if the rings could be worn already, they’ve only been in for 2-3000 km..
View attachment 260132
View attachment 260134View attachment 260133
I’m going to have to replace all the valves, as they are all out of specs in regards to stem size.. and I guess that means replacing valve guides as well, I’ll have to measure.
I just need to figure out if the oil could be coming from somewhere else, along with oil coming from the valves, I also noticed that all the valve seals, except for one, had already popped off the valveGuide.

If the valve stem seals were not fitted properly, that's where the oil has come from.

 

[Heinz Ketchup]

If the valve stem seals were not fitted properly, that's where the oil has come from.

I’ve had them come off a few times, if you look through this thread you’ll see that I have replaced the seals several times within the last couple of years, they come off after few hundred km.
I might be installing them incorrectly, though it seems unlikely, or the out of spec valves could be forcing them off?
In my head I’ve made sure the seals seat fully and stay in place, pressing them all the way down, is there some trick I’m missing?

 

[Its been a long time]

I’ve had them come off a few times, if you look through this thread you’ll see that I have replaced the seals several times within the last couple of years, they come off after few hundred km.
I might be installing them incorrectly, though it seems unlikely, or the out of spec valves could be forcing them off?
In my head I’ve made sure the seals seat fully and stay in place, pressing them all the way down, is there some trick I’m missing?

I see. I haven't experienced that, but haven't owned an XS650 for several decades until recently.

When I refurbish cylinder heads I have new valve guides made to suit the head from colsibro. Probably the best known "go to" valve guide material.

https://columbiametals.com/product/colsibro-2/

So the fitting of the stem seals is within my control. Never had one come adrift and that might be why.

It's a bit of a radical solution to your problem though.

 

[Jan_P]

Are you using poor valve stem seals .If I Recall right they should have a spring and a seat fixating in a groove
If I recall right they " Pop " into place -- someone else chime in.

https://yambits.co.uk/xs650-valve-stem-oil-seals-p-6694.html

 

[magoo66]

I always liked this rendition. Not sure who made it, I just found on the interwebs.
View attachment 256011

Missed this in November. I’m liking it also. The flatter seats haven’t taken hold in my older, once a pretty devoted XS/TX 650 early std purist mind.I’ve opened my mind a bunch and this rendition of the seat and rear grabs my eyes.

 

[Heinz Ketchup]

Are you using poor valve stem seals .If I Recall right they should have a spring and a seat fixating in a groove
If I recall right they " Pop " into place -- someone else chime in.

https://yambits.co.uk/xs650-valve-stem-oil-seals-p-6694.html



View attachment 260174

I’ve used a few different, they all have the spring and somewhat pop into place, some came with gaskets others bought separately, but they all start to leak after a while - why I’m suspecting that a bit of extra movement from the valve, caused by wear, could be the culprit.

 

[Jan_P]

I’ve used a few different, they all have the spring and somewhat pop into place, some came with gaskets others bought separately, but they all start to leak after a while - why I’m suspecting that a bit of extra movement from the valve, caused by wear, could be the culprit.

I dont have the Experience when it comes to this ,.What I Did was taking the head with valves to the dealer
The senior Mechanic there had the experience to feel the movement. Insert the valve pushing it sideways turning
And gave mine a pass Stating -- Not new but OK for Now.

There is very little play when new between the valve stem and guide

Short distance on the rings .Would be surprising if they are worn ..

 

[Heinz Ketchup]

Here’s a video showing the play between valve and guide - the gap is actually visible

 

[Heinz Ketchup]

I can't really tell what all is going on with your oil leak from the pic. You mention in another thread replacing valve seals multiple times (unusual), so I thought I'd mention it might be time to check the valve and valve guide for wear and proper fitment.

The manual (below) describes using a dial gauge to check side-play (<0.1mm, 0.12mm ) of the valve (raised 10mm) in the guide, but one can also check clearance with a ball-gauge and micrometer.
View attachment 244854

I was in a hurry so I only got to measure two valve seats, on the one with most and least wear on the valve stems - it seems like they were fine, measuring between 7.98 and 8.01. This would mean I should only replace valves? As the worst valves were .3 mm out of spec(measuring the width and not the side play as instructed, as I didn’t have a gauge suited for the job) seats were within spec.
i’ve never replaced valves before, therefore I’m unsure if the seats should be replaced at the same time.
Furthermore, I’m still trying to grasp that the wear on the valve stems should be the course of the seals popping off, and generally wear as quick as they have - I’m guessing the only solution here is to simply replace it and see if it fixes it, as bothersome as it might seem and annoying/expensive if it’s not the course of the problem

 

[Jan_P]

Can it be the surplus oil passing in gets Solidified and build up and then getting more friction between the Valve Stem and Seal

Thinking out loud here
If one puts the defect valves in .and turning the head over pour in liquid see if they are not leaking or can be tight with some lapping
I would think about having new valves with the correct valve stem dimension and lapping them .watching if they can be tight also.
Might Not be the correct way to do it But putting it out here

 

[Heinz Ketchup]

Can it be the surplus oil passing in gets Solidified and build up and then getting more friction between the Valve Stem and Seal

Thinking out loud here
If one puts the defect valves in .and turning the head over pour in liquid see if they are not leaking or can be tight with some lapping
I would think about having new valves with the correct valve stem dimension and lapping them .watching if they can be tight also.
Might Not be the correct way to do it But putting it out here

I tested the seal of the valves before removing collets, turned it upside down and poured in some liquid past the valves and let it sit, tried nocking around the block with the backside of a screwdriver to imitate vibrations and provoke a leak, but after two hours all the liquid was still there - the oil therefore has to come in when the valves open, having followed the stem.

I would love nothing more than an obvious solution, I might be looking at it wrong but the only logical solution in my head is the wear on the valve stems. Despite having to spend more money I’m leaning towards replacing valve guides along with the valves - my apologies I meant valve guides earlier when I said replace valve seats.

 

[GLJ]

my
I think you may be better off taking the head to a machine shop that does head work. They may look at them and tell you all you need to do is have the guides knurled and then sized for the valve. Or you may need new valves and guides. To my knowledge replacing guides is not as straight foreword as you may think. Also they should be able to tell you why the seals won't stay on.

 

[Heinz Ketchup]

Following this method I measured 0.20-0.35 mm side-play all around, which further confirms that the valves are done for.

Monday I’ll call a few shops to hear what they’ll charge to change valves and guides, before I start doing it myself.

Good thing I’m not doing this as a business, there’s no way restoring and maintaining old bikes makes economic sense unless it has an emotional and curious learning value

I can't really tell what all is going on with your oil leak from the pic. You mention in another thread replacing valve seals multiple times (unusual), so I thought I'd mention it might be time to check the valve and valve guide for wear and proper fitment.

The manual (below) describes using a dial gauge to check side-play (<0.1mm, 0.12mm ) of the valve (raised 10mm) in the guide, but one can also check clearance with a ball-gauge and micrometer.
View attachment 244854