Skorpion 660 Lightweight Build

[breakwellmz]

Hi

All looking good.
What is that plastic tank above the silencer, radiator overflow tank? There isn`t one on the Mastiff, can`t you get rid?

Cheers

[jpmsteadi]

yes, thats the coolant overflow tank. I think I probably could get rid of it, but its not a bad thing to have. makes burping the radiator easy too (since the overflow tank is the highest point in the system). once I get the plastics mounted it will be hidden.

[breakwellmz]

Here is one more picture closer of where the thermostat ends up.
Initially I was thinking I would need to build or 3d print a bracket for it, but it seems to be very well held in by the hoses, the oil return line from the head, and the clutch cable.

Well here`s mine.
Took a lot of time to end up with something fairly simple looking. From the RH side it looks no different and unless you know what you are looking at the RH side looks quite `normal`. I removed the fan after realising that the only time it comes on is when i leave the bike idling just to see if the fan comes on!
Much to my surprise it does seem to run better!

[jpmsteadi]

nice, that looks great! I might add the fan back on if I was gonna go offroad, but I bet for normal riding doesn't really matter.

[breakwellmz]

I must admit i`ve had very little to do with motorcycle water cooling systems but I was surprised to find that even with the KTM thermostat closed there was a small supply to the top of the radiators, but then they are losing some fluid from the bottom even with the thermostat closed?
My closed thermostat/radiators by-passed coolant route isn`t as direct to the water pump as yours which i`m still thinking about.
This all WITHOUT instruments remember!

[jpmsteadi]

Yes, it seems like mine has a tiny bit of bypass too. The thermostat isn't a full open or close thing, its a gradual opening and closing as the metal inside expands and contracts, so even if the theromstat is fully open at, say, 200 degrees, it is going to start opening well below that. So my guess is there is just a little bit of leak by. I notice my temp gauge (which is in the radiator) getting warmer even as the engine is still warming up. Once it is warm it doesn't seem to drop back below 100 degrees, so there must be at least some flow with the thermostat closed.

[Puffs]

nice, that looks great! I might add the fan back on if I was gonna go offroad, but I bet for normal riding doesn't really matter.

Exactly. Try a difficult climb - that's when they boil.
But that's not for this bike, I'd guess.

[jpmsteadi]

not sure what breakwellz's goal for his mastiff is, but I have a fan on mine. I ride enough in Atlanta traffic, I'm be scared of overheating

[breakwellmz]

Goal? - To make it more efficient including getting rid of stuff that isn`t necessary, i don`t get stuck in traffic i go past it!
What does yours weight now, have you weighed it?

[jpmsteadi]

you lucky devil with your lane splitting.

Just weighed it, surprisingly heavier than it feels to ride. 359lbs using the bathroom scale on each wheel with a spacer of wood for the other wheel. thats with a little over a half tank of gas.

[breakwellmz]

This is the main route in/out of Bath at busy time. I actually enjoy getting through this lot on the bike and feeling smug as i go past them! Are you not allowed to filter through?

The official dry weights of both Mastiff and Skorpion are 380lb (there looks to be more to the Skorpion) so you`ve lost a decent amount. You don`t have a `before` weight measured the same way for comparison?
Your Skorpions centre of gravity will be lower than my Mastiffs i bet.

[Puffs]

That's exactly what part of my route looked like, and what I bought the 251 for...

Yes I see 173kg/381.4lbs as dry weight, but be careful what manufacturers mean by 'dry weight'. I liked to think of it in the sense as meant in the FIM rules: the minimum weight of the bike on the track. So that's in running order, yet without fuel. But that's not necessarily so.
Some manufacturers (e.g. Ducati) mean by 'dry weight' the weight of the bike without any fluid, so without fuel, oil, cooling fluid, and also without battery. So that's how it leaves the factory, but other than that it's quite pointless as you cannot run the bike without oil, cooling fluid & battery.
Not saying that MZ did this, but even so, also this 381lbs might have been an ambition.

[jpmsteadi]

Alas, everywhere in the USA we can't lane split or even filter at lights except for California. I think that has a lot to do with the perception of motorcycles in USA. Using them as transportation isn't a common idea of why you would get a bike.

I didn't weight the bike exactly the same, but closely weighted it at 398. I didn't have that shim under the other tire, so I expect that is a bit lower than it actually is.

I do have a bit more weight to loose: tabs on the rear subframe, finally trade out that battery, take off the wideband O2 sensor once the fueling gets good.

That all being said, it feels really light. A lovely different type of bike than the others I have.

[droy]

wheels make a big difference. There are option that allow for a 15 lb rear wheel weight savings. I'm sure your R6 wheel is a few lbs. lighter.

[jpmsteadi]

What rear wheels save 15 lbs?!


And yes, the fork swap saved about 6 pounds I think.