Kick a** two strokes!

Saturday it was time to put a new pipe on my 2011 YZ125...   
A hard 35 minute moto at the sand track makes a pipe look great.

Winter had us doing a full ground up resto on our ‘07 CR85. This thing is brand new from the tits on the tires to the grips. Still looking for some of the old goodie parts if anyone has any leads on some, let me know. We are currently racing this unit and the thing rips! 

Bike and gear combo look so good! I’m sure you got a happy kid! Honda would still sell a fair amount I think if they kept making them, probably would sell more 85s than 150s.

You said it rips, did you mod the engine? I’m wondering if modded if it can be as fast as a stock ktm 85.

It makes me want to have one to play around and match it with my 2004 CR250.

My son had an '03 CR85.  Once jetted properly, it ripped.  To tell the truth, the thing scared me a few times.  No power valve and a full-on two stroke hit!

I think you're right.  Update the motor/frame/suspension and electronics a bit and I think the package would be fully competitive.

Engine is all new stock. I did end up picking up a spare motor and have plans to dump a bunch of money into that I’ll never get back BUT oh well who cares! I did add a Moose 10mm intake block, vforce3, jetted to spec (but still searching for a NBKF needle), MSV high output coil, boyesen x wing, scalvini true cone pipe with pc shorty(if anyone at bills pipes wants to sponsor I’d love a works pipe/carbon silencer for this unit). This is his first year on 85s so I thought it would be cool to have something that stands out while he’s learning the bigger bike. Here’s what really sold me on going this direction. Specs really aren’t that far off minus no power valve.

2025 KTM 85sx 17/14 specs

Engine
Engine Type: Single-cylinder, 2-stroke, 84.9 cc
Bore x Stroke: \(47 \text{ mm} \times 40.8 \text{ mm}\ Horsepower: 25hp
Starter: Kickstarter
Fuel System: Carburetor
Transmission: 6-speed, manual
Clutch: Wet, multi-disc clutch, Formula hydraulics [1, 2]

Chassis & Suspension
Frame Type: Central double-cradle 25CrMo4 steel
Front Suspension: WP XACT 43 mm USD fork
Rear Suspension: WP XACT PDS mono shock
Suspension Travel (Front/Rear): 278 mm (10.9 in) / 305 mm (12 in)
Steering Head Angle: 66° [1, 2, 3]

Brakes & Wheels
Front Brake: 240 mm Disc
Rear Brake: 220 mm Disc
Front/Rear Tires: Maxxis® MX-ST 70/100 R19 / 90/100 R16 (on 19/16 model) [1, 2]

Dimensions & Capacity
Weight (Without Fuel): 149.9 lb / 68 kg
Fuel Capacity: 1.37 gal / 5.2 l
Seat Height: 34.4 in / 875 mm (19/16 model)
Ground Clearance: 362 mm (14.25 in)

2007 Honda CR85 

Engine: 84.7cc liquid-cooled single-cylinder two-stroke

• Bore & Stroke: \(47.5\text{mm} \times 47.8\text{mm}\)
• Compression Ratio: \(8.4:1\)
• Induction: Reed valve, 28mm flat slide carburetor
• Transmission: Close-ratio six-speed
• Suspension Front: 37mm fully adjustable leading-axle inverted Showa cartridge fork; \(10.8\text{ inches}\) travel
• Suspension Rear: Pro-Link fully adjustable Showa single shock; \(10.8\text{ inches}\) travel
• Brakes Front/Rear: Single disc
• Seat Height: \(32.4\text{ inches}\)
• Wheelbase: \(49.1\text{ inches}\)
• Fuel Capacity: \(1.35\text{ gallons}\)
• Curb Weight: \(144\text{ lbs}\) [1, 2, 3, 4]

CR85R Expert (Big Wheel) Variant

The Expert model (CR85R adds larger wheels (\(70/100-19\) front/\(90/100-16\) rear), a higher seat height (\(34.0\text{ inches}\)), and a longer swingarm for a \(50.7\text{-inch}\) wheelbase. [1, 2, 3, 4, 5]

Performance

• Horsepower: \(\approx 25.8\text{ HP} \ (19\text{ kW})\) @ \(12,000\text{ rpm}\)
• Final Drive: #420 chain; 

Is that a quick turn throttle?

So much is Trick about this circa 1990 (?) Mugen, but Bloody Hell, those Pegs are a throw back to the 70s!

I can't recall the std ones on my 89 CR125 chassis I used  ( still got) for a 4t conversion, as I cut them off, at the time, and welded on KX Pegs, which were the beginning of bigger pegs

And, what's this - I thought it might relate to some sort of remote PV adjuster, but that's just a wild guess on my part :

Classic MX in Austria on my KTM Big Bores 

The cable on the right is the throttle cable, I assume the cable on the left goes to the carb...

I thought it might be a like an easy clutch...

but reducing how much rotation is needed to fully open the throttle.

Wow, what a thing of beauty!!! I never thought I would see a fucking unicorn! But here we are. Did you ever ride it? That’s some factory unobtainium right there.

So many interesting details on that bike, like the aluminium frame braces between lower suspension link and the swingarm...

A guy called Bradley Briggs from england owns that Casio Mugen pictured above....

Pretty sick lot of mugen and HRC stuff cool

I think it's blue duct tape. Maybe to close off that part of the frame, which is normally open to the elements. Might have been a good idea at a sand or mud race.