What have you done to your XS today?

Took it for a 30 minute ride today to see how hot the bike gets and this was the result:
View attachment 170892
115C at its highest which is 239F. Kinda makes me want to install an oil cooler. It took a long time to get that hot and then the clutch started to slip a bit. Other than that it was a nice ride.
More educated minds here might disagree, but unless you’ve got oil flow issues, that doesn’t seem terribly hot to me on an air cooled bike. What is the shear temperature for the oil you are using? Is the bike detonating or noticeably losing power at any RPM range? Is it using an abnormal amount of oil? Are you getting oily smoke through your exhaust? Are you noticing any metal flakes, glitter, or shaving on your sump plugs when you change your oil?

If the answer to the latter of these is “no” then I’d probably run it until something presents actual symptoms. The problem with those dipsticks is they don’t present an acceptable temp range, and even if they did, that might vary based on any number of factors. So you can worry all you want about it, but I’d lightly suggest finding out the shear temp - or the temperature at which your oil loses lubricity + becomes a liability rather than an asset to the system - and use that as a first step toward establishing a threshold for concern.

Too long, didn’t read? Here’s two points of consideration:

1. 239F is likely not “too high” from an oil temp perspective on an air cooled engine with not much blocking the breeze.
2. More data is not always helpful without context.
 
115C at its highest which is 239F. Kinda makes me want to install an oil cooler.

Hi @Tiesco

Petrol, when it burns, produces an equal quantity of water and CO2. So one pound of petrol produces one pound of water vapour and one pound of CO2. Most of the water vapour goes out of the exhaust. But some ends up in your oil. Unless the oil gets to over 100 degrees C (the boiling point of water) that's where it stops.

I'd do some research before I started cutting and drilling. A very quick google turned up this from something called Hotrod.com

"For a dual-purpose car, engine oil needs to be at least 220 degrees F to burn off all the deposits and accumulated water vapor. For every pound of fuel burned in an engine, the combustion process also generates a pound of water! If engine sump temperatures rarely exceed 212 degrees (water's boiling point), the water will mix with sulfur (another combustion by-product) and create acids that can eventually damage bearings.

As for ultimate power potential, the general consensus among most racers is that hot oil and cool water make more power in most engines. Cold engine oil causes excessive frictional drag on the bearings and cylinder walls. A quality conventional motor oil will tolerate oil sump temperatures of up to 250 degrees, but starts breaking down over 275 degrees. The traditional approach is to try to hold oil temperatures between 230 and 260 degrees. Even on a short-duration, drag-only combo where oil is frequently changed, I would not want to routinely see under-200-degree oil temps."

Anyway, hope this helps.

Dave
 
Air cooles VWs run with cylinder head temps around 300*F, critical "overheat" temp around 425-450. And most people agree oil temp atleast 220*F to burn out moisture. Some see over 300 on oil temp in traffic. So I would say you are probably fine.
 
Thanks for alleviating my concerns, yall.

I would have liked to see it run at like 220F personally but seeing as its supposed run that hot I guess I'm not that worried. It didn't seem like it was suffering at all being that hot. It ran just fine.

Also @Tiesco your clutch slippage may be related to friction modifiers in the oil that you're using, the condition of your clutch plates + steels, etc.

Buzz i run oil that says it has friction modifiers for wet clutches. I also have new friction plates.
 
If you're still running the original stock clutch springs, that could be the problem. Most have gotten weak by now. Aftermarket slightly stiffer springs are cheap and what most of us switch to.
 
If you're still running the original stock clutch springs, that could be the problem. Most have gotten weak by now. Aftermarket slightly stiffer springs are cheap and what most of us switch to.

I installed new, stiffer springs as well when I installed new friction plates. I forgot to mention that. I think the pushrod just needs a little adjustment.

I have a one piece pushrod that I have yet to try out.
 
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All 650 springs weaken. I have seen lots of stock OEM Valve springs that you can take out without a spring
compressor, just your fingers.
 
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Small Bit - Big Improvement
Factory direction light lost its pin and started rotating freely. The head of a 2 inch plain finishing nail is a tight fit into the hole, so I cut the nail down to about 1/4 inch and tapped it home. The thinner shaft goes into the hole in the centre piece and the head jams tight into the outer.
All better!
 
Looks like I have to run a base gasket. Used some .050 solder as a crush measurement for the squish band and came up with .02-.025". Need atleast .040" from what I've read, so base gasket goes in. I checked in 4 spots, by the valves and 90* to the valves. All came out in the same range.
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Hi @Tiesco

Petrol, when it burns, produces an equal quantity of water and CO2. So one pound of petrol produces one pound of water vapour and one pound of CO2. Most of the water vapour goes out of the exhaust. But some ends up in your oil. Unless the oil gets to over 100 degrees C (the boiling point of water) that's where it stops.

I'd do some research before I started cutting and drilling. A very quick google turned up this from something called Hotrod.com

"For a dual-purpose car, engine oil needs to be at least 220 degrees F to burn off all the deposits and accumulated water vapor. For every pound of fuel burned in an engine, the combustion process also generates a pound of water! If engine sump temperatures rarely exceed 212 degrees (water's boiling point), the water will mix with sulfur (another combustion by-product) and create acids that can eventually damage bearings.

As for ultimate power potential, the general consensus among most racers is that hot oil and cool water make more power in most engines. Cold engine oil causes excessive frictional drag on the bearings and cylinder walls. A quality conventional motor oil will tolerate oil sump temperatures of up to 250 degrees, but starts breaking down over 275 degrees. The traditional approach is to try to hold oil temperatures between 230 and 260 degrees. Even on a short-duration, drag-only combo where oil is frequently changed, I would not want to routinely see under-200-degree oil temps."

Anyway, hope this helps.

Dave

Per above temp posts, I've had a good working relationship with a Harbor Freight laser thermometer ( port exits; cast iron engine blocks; aluminum sumps; individual cylinder head spots; coolant in and out hoses). Also, I used to get 'garments' out of my trunk to block the radiator if the oil wouldn't get hot enough to boil water 100deg C...and heat me legs.
 
Spoke with a nice lady from Rustoleum today...asked her why my shiny black paint was getting little bumps. After the interrogation she said hold the can closer. Wait 2 days before you sand the little bumps and only use a wet rag to wipe off. Said: OK, but this frame painting is '2-daying' me to death. I'm holding my original chrome gas cap center piece w/ logo wondering if the replica Mike's has is plastic/ chrome or metal?....Headed to ACE hdwr store to find some rubber to put over the old hard gas cap rubber so it won't leak upside down tank acid / cleaner crud.
 
Probably take enough torque to damage parts. I ran a die down to make sure they're clean, it didn't do any cutting.
 
This morning found where the 7.90 mm ball bearing (that fell out of engine) lives....same place where the clutch rod with the petrified wax/ grease lives. Tapped on the rod and it fell out too. ***note: pp. 65 :service repairs, adjustments clutch diagram. When the sun comes up will sand smooth the frame topcoat where it has micro pimples and respray. Dump Evapo-Rust out of fuel tank. Got all the inside top of tank crud out, everything clean as a whistle inside. Rinse tank now,fill with hot water and Kirkland (COSTCO)'s finest dish washing soap. I have to think it's that Myer's 'Clean Day' soap private labeled. Best de-greaser I've used that rinses clean, streak free and I wash my hands, face and black paint off my feet. If no rain later today, rinse out soapy water, hit tank with POR-15's metal Prep for a very short period, rinse and pour in the POR-15 liner. Tank should be ready to see a painter next week after curing. I disassembled the original gas cap, de rusted, de-crudded metal, will replace on tank to help with lining treatment (piece of plastic wrap under cap). Duct tape fails. I need lakeview's magic wand.
 
All I can say is ..by the time I dumped that Phosphoric acid and Zinc out of the gas tank, I wanted to just leave it it was so clean. 12 hrs. and counting now w/ sealer. Added some bling to my frame paint...had half a can of the semi-gloss left so grabbed a can of black gloss # 779830 Rustoleum, re-coated the sanded semi-gloss parts removing texture where needed. Also finished off top area and steering tube area...mostly areas you can see on a built bike. This paint flowed better than the automotive / protective, hi-zinc 'new formula stuff...Paint the ft. engine brackets and swing arm gloss today. P7020601.JPG P7020601.JPG
 

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