An introduction and question

OK.. have been thinking about the rockers and questing what looked like lines across the face. So, I may be breaking every rule on this, but I took some 2000 grit wet or dry, soaked it with WD40 and lightly worked it over the wet or dry on a surface plate. And this it what I have.
There's no pic there.
 
OK I see the pics now...
So I have a few 650's under my belt but have never come across this. Besides needing new ones anyone have ideas on what caused this?
Suppose it's possible someone trashed them and the cam, replaced the cam but didn't change the rockers? Not sure what else would do that to the rockers and leave the cam in good shape. You'd think both would be affected...
 
... questing what looked like lines across the face...

...anyone have ideas on what caused this?

I've seen many pics like yours, a singular line spanning across the center of the pads, and have only a speculation.

The acceleration profile of the valves shows tremendous force occurring in the first and last 15% of the valve travel (blue line).
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It's likely that a lubrication film failure occurs, at high rpms, at those high-load points, starting with a narrow wear line, widening over time...
 
It's likely that a lubrication film failure occurs, at high rpms, at those high-load points, starting with a narrow wear line, widening over time..

TwoMany, The graph certainly does offer an explanation and even more reason to pay particular attention to oil pump specs when I rebuild it.
 
TwoMany, The graph certainly does offer an explanation and even more reason to pay particular attention to oil pump specs when I rebuild it.
Pretty common issue is oil diluted with gasoline from carbs overflowing.
Check the pump vanes for excessive scoring then IMHO More importantly; oil viscosity, change intervals. Maybe a "real" filter in place of one of the screens.
 
Thought I might share the results of soda blasting motor parts. I cannot say enough positive on how well it removes old gasket and cleans gasket surfaces.
Before blasting
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After blasting
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On the down side. I'm not sure of exactly what causes it, oxidation, staining or maybe both, but soda does not seem aggressive enough to get cast parts to a uniform "clean" look.

Before
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After
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I did make a new nozzle to make it easier to get in between the fins. The original is thick with a moderate taper and .268" diameter hole. The one I made has a .187" hole and an outside diameter of .277". The smaller ID tip worked much better, not only if getting deeper into the fins, but also concentrated the spray which improved cleaning.
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So what's next???? I stopped by a local powder coating business and showed him the results of my soda blasting. During my visit it became very apparent he has an affinity for old motorcycles and offered his help. Today 'Ill finish masking off everything and get the parts to him. Pics to follow
 
Maybe a "real" filter in place of one of the screens.

gggGary, you hit the nail on the head. With a motor already showing issues I sure will be paying extra attention to oiling. As for better filtering, already going in that direction. I'll be adding a couple of neodymium magnets and will post some pics when done.
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Yes, I don't think soda is aggressive enough to clean off heavy corrosion and staining. I bead blast instead. You just need to make sure you block off all openings and don't blast any internal surfaces .....

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I've "upgraded" my plywood covers to aluminum plate w/rubber sheet. The covers for the cylinder sleeves where they hang out the bottom of the casting are spreadable frosting containers. They're the perfect size for a tight slip fit. In fact, it helps if you warm them with a hair dryer or heat gun on low to get them on and off.
 
While waiting for seals and gaskets to arrive I thought I would finish up my oil filter by adding a magnet. Bought a three pack of 25mm x 3mm round neodymium magnets from eBay. Pretty straight forward process: 1" diameter end mill to 3mm depth but instead of just JB welding it in place I added an 8-32 flat head screw as insurance it stays put.

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Drill, tap and counter sink so the head is flush with the surface. I did seat the screw in a bit of JB weld to make sure it stays put and because it is a thru hole into the oil passage to seal things off.
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Added JB to the circumference of the spot face to hold and seal the magnet.
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Last thing was to drill bolt heads so they can be safety wired.
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Jim, If you don't mind I have a few questions about painting my engine cases with POR15 engine enamel. (Maybe your painting thread would be a better place to ask and if so we can move the question to there) Anyways.... Did you spray or brush? If sprayed what did you reduce it with? Also, the Evercoat hardener you used. The instructions on the POR15 paint makes no mention of needing a hardener. Was this added to get the smooth wet look your cases have?
 
Jim, If you don't mind I have a few questions about painting my engine cases with POR15 engine enamel. (Maybe your painting thread would be a better place to ask and if so we can move the question to there) Anyways.... Did you spray or brush? If sprayed what did you reduce it with? Also, the Evercoat hardener you used. The instructions on the POR15 paint makes no mention of needing a hardener. Was this added to get the smooth wet look your cases have?
Here's fine Jake. Yes, I sprayed it.... thinned with plain old lacquer thinner. I've learned from experience that adding the generic hardener isn't just a gimmick (I was a skeptic), it does actually harden the paint quiet a bit. Also gives a fair bit better solvents and gas resistance.
 
Thanks Jim. Forgot to ask about surface prep. My cases have thus far have been soda blasted and pressure washed with water only. Did you wipe them down with anything prior to spraying?
 
While waiting for seals and gaskets to arrive I thought I would finish up my oil filter by adding a magnet. Bought a three pack of 25mm x 3mm round neodymium magnets from eBay. Pretty straight forward process: 1" diameter end mill to 3mm depth but instead of just JB welding it in place I added an 8-32 flat head screw as insurance it stays put.

View attachment 155610

Drill, tap and counter sink so the head is flush with the surface. I did seat the screw in a bit of JB weld to make sure it stays put and because it is a thru hole into the oil passage to seal things off.
View attachment 155611

View attachment 155612

Added JB to the circumference of the spot face to hold and seal the magnet.
View attachment 155618

Last thing was to drill bolt heads so they can be safety wired.
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View attachment 155621
SaWeet!
 
Well, I have my crankcases ready to paint; but for the past couple of weeks it just would not warm up enough to do them And the long term forecast does not look promising either. So to try and keep things on track I'm taking a carb detour. The electric start engine I picked up did not have carburetors so my plan was to use the stock carbs from the Orange bike and use a set of round slides I have on the Orange bike. All I needed was manifolds for the round slides. Starting with a 3.75" diameter hunk of aluminum the chips started to fly. (So I can folks asking 3.75" diameter for a little manifold? Well I needed at least 3.5" for the flange width and I had it on hand)
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With the lathe work done it was on to the mill. With the first sides cut to width on the X-axis the part needed to be rotated to 72 degrees for the other sides.
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Times two and they were done save mounting holes.
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And here is why no mounting holes.
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Having a few XS's under my belt, I have to admit I never paid much attention to carb angle because I always went back to stock configuration. So now I find myself outside of my area of carb knowledge. How important is it that the carbs set more level to horizon? Also while asking about angle, what is the smallest air filter available? Things are a bit out of perspective in the pic, but things are a bit crowded on the back side.
 
Looks to me like you've enough flange there to re-cut the faces at a 10-15 deg. angle? At least you haven't drilled 'em yet.
 
Yup Jim... That is exactly why those holes are a missing. I did go back out and took some time to really get the bike as close to level as I could on the stand and the angle is much better, but I still have some. I'll break out the angle measurin tools and get it nailed down.
 
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