ae86andkp61’s Moto fleet; too many bikes, so little time

I have no idea if anyone will be interested in reading along, but I figured I'd start a thread on my various bikes to document my modifications, improvements, adventures, maintenance, and marginally-successful attempts at downsizing my collection.

Backstory: From 10 years-old or so through my teens I obsessed about bikes; cars were a way-less-captivating afterthought. My dad rode, as had his father, so I came by it honestly. I bought a Honda CR125 project at 13 or so. It was my first vehicular project. I rebuilt it with my dad, learned to ride, and scared myself silly riding that two-stroke around the rural property I grew up on. After taking a break in my 20's and early 30's (which was probably for the best) I rejoined motorcycling nine years ago, and realized that it is one of the most fun things I've done in life, and I can't imagine not riding.

The ease of working on a thumper and the adventure potential of a dual sport really appeal to me, so I dipped my toes back into the pool with a Suzuki DR350SE which rapidly became several DR350s, including one which I completely rebuilt and modified pretty radically.

As fate would have it, I scored a deal on some DR350 supermoto wheels, and my world was forever changed.

I loved the supermoto...so much fun! The combination of long-travel supple suspension, narrow and super-lightweight, torquey power delivery, and upright ergonomics suited my typical rides perfectly. I planned on swapping wheelsets as needed, but in reality the 17s stayed on the bike most of the time.
 

In the interest of branching out a bit, I bought a rough wrecked Suzuki 400 Bandit project and restored it to have a multi-cylinder street bike. I'd lusted after one since they first came out, and I wasn't even legal riding age at the time. It was fun to see my efforts transform the gaudy wreck back to presentable, and more power and tons of revs were fun, but cleaning, syncing and maintaining four cylinders with four carbs was a lot of extra effort over my usual thumpers.

I was also around waist-deep into a custom DR350-based cafe racer build when I learned of the JDM Suzuki Goose 350 via one for sale the next state over! After I got over the feeling that an early-90's Suzuki designer was somehow in my head, I bought it, and commenced with fixing it up. I love the style of this bike. The familiar mechanicals were a nice bonus, and I told myself the riding position would provide motivation to stay fit and flexible. 

I'm not sure this continued backstory is chronological, but close enough. My best friend and the main instigator for getting me back into riding had a Suzuki Bandit 1200S. We would zip around town together, which was super fun. Stoplight-to-stoplight, my little bikes could hang with the big oil-cooled bruiser he rode.

Then a cargo van driver decided to back up without checking behind, and knocked over and drove up on top of the big Bandit and ruined it. My best friend had insurance money in his pocket, and asked me what he should get...I knew exactly what to recommend, and told him he should get the newly-released Husqvarna 701, which he did.

We started doing longer rides together, way out of town on varied surfaces/terrain, which was awesome, but the performance disparity between our bikes became more apparent, and I craved more power so that I wasn't maxed out at 80-something mph, or struggling because we were headed uphill, and the ease of fuel-injection looked appealing as well.

At the time, I couldn't afford a 701 of my own, and started researching what might get me closest to that power/weight with EFI on the used market, and landed on the little Aprilia V-twins, the SXV/RXV 450/550, so I hunted for months before buying a SXV550.

Wow! This bike set my world on its ear! The grip, the power, the brakes, the sound. Sadly, I struggled to get it and keep it running in tip-top shape. These bikes are often labeled as unreliable, but I honestly think 98% of the issues stem from owners who aren't onboard with what the bikes require, and I certainly fell into that category.

Through a twist of fate, and a less-than-optimal hip surgery result with my best friend, I ended up as temporary caretaker for the 701. 

The 701 was the bike I found myself riding the most. Same weight as the DR350, but double the power, waaay better chassis and brakes, EFI refinement, and great transmission ratios. The SXV has more sex appeal and feels more special than the Husky, and is 30-some pounds lighter (!!!) but is nowhere near as refined, let alone reliable.

I saw the writing on the wall and started selling off the DR350s. I also sold the Bandit 400.

My best friend made me an offer I couldn't refuse and sold me the 701! I promptly set about getting supermoto wheels for it.

A coworker approached me (as the workplace motorcycle expert) wondering where he might unload his beloved VFR800 in an effort to raise some quick cash since he was under duress. Always one to help out, I bought it!

At first I thought the VFR would be a flip, and I didn't really like it, but then the pandemic hit and I took it for a long all-day ride way out of town and realized I'd been riding it wrong! With my previous bikes, I blasted around the city, and sought out the tightest and twistiest backroads, and was attempting the same with the big Honda, and wasn't loving it, since it is heavy with limited steering lock, tall gearing, and a jerky throttle/fueling at low rpm. Once out on a more open two-lane highway, the bike came alive, and I frequently exploited VTEC and started to fall in love. Not long after, I rebuilt the front suspension with custom spring rates and damping, plus a matching custom-built rear shock and now the bike is awesome for longer rides on leg-stretching roads.

I also picked up a super-low-miles-but-sat-a-while JDM GSXR250 restoration project after my dad and I visited a local Japanese importer on a whim "just to look" and both ended up buying bikes! 250cc in-line four, but with slightly more upright ergonomics than many in the class, and only two carbs instead of four (I'm slowly learning) which should maximize riding time, rather than wrenching. This should provide the top-end rush and classic Japanese inline four sportbike sound, but at legal speeds, which is appealing for my middle-aged risk-adverse riding style.

After a long period of deliberation and wavering, I finally sold the Aprilia recently, which was mixed for sure. Not easy emotionally, but very easy logically.

To fill the street-legal-supermoto-race bike-shaped hole in my heart, I bought a super low-hour Husaberg FS570 which popped up locally. I've had my eye on these for a while, lighter and racier than the 701, more reliable and longer service intervals than the SXV, but cut from the same cloth. So far it has been awesome! Best supermoto chassis so far!

So as of spring 2023, the fleet consists of:

2016 Husky 701 Supermoto/Enduro

2011 Husaberg FS570

2006 Honda VFR800 VTEC ABS

1992 Suzuki Goose 350

1988 Suzuki GSXR250

Now that we're up-to-speed, I intend to start documenting the issues, service, and upgrades on these bikes.

Cult bike much?

Super cool collection.

Following

wheelsmithy (Joe-with-an-L) said:

Cult bike much?

Super cool collection.

Thanks! Life's too short to waste time on run-of-the-mill commonplace bikes.  My dad influenced me here as well, he's had a BMW /2, a handful of Ducati Desmo singles, a couple Husky two-strokes, a Kawasaki GPz550, a Yamaha SR500, a couple Honda NT650 Hawks, and a Honda CB-1 to name but a few.

The Goose came from Japan with a bunch of modifications, including a Yoshimura titanium full system with straight-through carbon can, Keihin FCR39 flat-slide pumper carb, a remote reservoir Fox rear shock, and braided brake lines. It was apparently a trackday bike in Japan.

The bike originally came from Suzuki with an airbox and a BST40 constant-velocity carb. My bike has no airbox. The previous American owner welded a ring *inside* the bellmouth of the velocity stack and added a tiny pod filter. 

The bike had been sitting a while, so I went through the entire fuel system. The first few rides were an adventure of fuel clogs, minor fuel leaks, and general fuel hiccups. I got it to a stable, but untuned baseline where it ran without leaking or sputtering, and was able to get consistent fuel through the primary and reserve plumbing. I think I totally disassembled and cleaned the carb at least three, probably four times as I worked all of the gunk, sludge, and flakes out of the system.

Whoever put the bike together had a real eye, IMO, and the look of the bike was just about perfect to me. The electric blue metallic paint, the careful deletion of a few stock parts that really enhanced the looks, the ti exhaust with beautiful bluing, including shades of purple and copper, and then the accents like the coppery-orange velocity stack, and a few purple-anodized aluminum bolts. I wouldn't have done it myself, but after seeing it in person, I wanted to keep the look mostly intact.

I wanted filtered air, but also wanted good airflow into the engine, so I found a guy making FCR velocity stacks for Ducati and KTM twins. I called him and he had a leftover single on the shelf, anodized dark orange (!!) so I bought it, and did a lot of trial and error to get a filter to fit. Most of what would clamp over the bell was huge and hard to fit, but I figured better a big filter than a small one. I ended having to modify the idle air passages in the stack as the filter I ended up with was clamped to the bell and not the shoulder, so it obscured the holes when clamped in place.

To make it a little more road-friendly, I built my own crude dB-killer for the muffler and repacked it. I figured I'd finish all changes to the intake and exhaust before jetting the carb to minimize the amount I'd have to re-do.

I also swapped the speedometer to an mph unit, and swapped the headlight for one with the correct beam pattern. Bandit 400 parts bolted right up! The useless single square mirror mounted above the bar, threaded into the perch (it had Kawasaki stamped on it) had to go. It presented a perfect view of my elbow, and if I moved my elbow out of the way, a perfect view of my hip! It was mounted on the left side, so perhaps it was added by the previous American owner. In any case, I swapped to dual bar-end mirrors for a decent combination of visibility and aesthetics.

The bias-ply Pirelli Sport Demons were fairly old, so I searched around and finally found some radial sticky tires (Bridgestone s-20-something BattleAxe) in 110 front and 140 rear sizing.

After riding around more, the tank started leaking through a couple pinholes in the bottom of the tank. The tank had a (failed) liner in it, so I found the best blue tank I could on Yahoo Japan Auctions and bought it. The new tank wasn't as nice on the top side, but looked salvageable and wasn't previously lined. I had it professionally cleaned and lined to keep me rolling while I figure out how to tackle the original lined tank, which is beautiful on the top side.

I built a self-contained tuning setup to use on carbed vehicles. It has a wideband oxygen sensor, a compact digital AFR gauge, decent lengths of wiring, and wiring for power and ground in a compact male two-way connector.

Since building the setup, among the first order of business for any carbureted vehicle is a wideband bung (with plug) in the collector, and adding the appropriate female connector to the vehicle near the dash with switched 12V power and ground, and I can just plug it in and go monitor on the road for tuning.

The problem with this setup for the Goose is the titanium exhaust, which I can't weld. I wasted waaay too much time exploring and mocking up for building the same exhaust in mild steel, which I can weld, for testing purposes, but I never finished it.

Eventually I reached out to someone with massive ti fabrication experience, someone I had tangential connections to through work, and he was amenable. It turns out he is a car/bike nut, so he was actually quite interested in the project, and it came out great!

On the to-do list before riding this year:

-Fluid changes

-New brake lines, which are already in hand

-Add wideband tuning setup and start collecting data

Optional is lengthening the kickstand. I'm not sure if my bike's original was shortened, or if the previous owner jacked the rear up and dropped the front so much that it leans pretty far over. Either way, a longer stand will help with the lean.

A little further out is sorting the prettier tank, and converting the tail section from a useless pillion seat (no passenger pegs, plus 350cc air/oil-cooled is already working hard enough hauling my fat ass around) into a solo cowl. I've also noticed a sporadic neutral light that might benefit from a look-see.

This weekend I drained the old oil and sent it off to Blackstone for analysis. I replaced the poorly-drilled sump tank plug (drilled for safety wiring) with a new magnetic drain plug, along with new sealing washer.

Nice Brittania fairing on the 701.  What year is it?  I really love my 18 690, although the new Aprilia Toureg is catching my eye.  The relative lack of dealerships and worries of parts supply and reliability are keeping me away from it.  I'll see how the first year or two fare with it and then decide.  Maybe I can find a lightly used one with all the good farkles on it then.

Please post pictures of that tuning setup when you have a chance. 

I think I have some photos of the setup by itself, but not sure where...or I can take some next time I'm out at the shop.

I got the sensor and inline controller from AEM. The controller doesn't include a gauge, it is the UEGO inline with outputs which I ran to a little digital gauge I got somewhere.

Here it is in use on the Bandit years ago:

While riding, I can discern things like "it does XYZ under increasing part throttle," but I'm not sure I am calibrated to distinguish between increasing 3/8ths throttle and increasing 1/2 throttle, so I calibrated the right handlebar.
 

The gauge is in the map pocket atop the tank bag (it is indiglo backlit when running) and the controller (which is a little bigger than a cigar, but small enough to fit in your hand) is in the bag. There are wires running down to the bung I welded into the collector in the exhaust and forward to the plug I put in the motorcycle harness for power and ground.

Why do such small differences in throttle opening matter? Different tuning variables in the carbs!

docwyte said:

Nice Brittania fairing on the 701.  What year is it?  I really love my 18 690, although the new Aprilia Toureg is catching my eye.

Thanks, I've enjoyed reading about your 690! I loved the Britannia on my DR350, so it was one of the first mods for the Husky. The 701 is a 2016 Enduro. I've also toyed with the idea of a Tuareg, but I'm gun shy as well...I'm not sure I could give up the option of both supermoto 17" wheels and 21"/18" Enduro wheels, and the added weight. There are many twin-cylinder ADV bike riders who love to chime in and say it isn't really that much heavier, and/or it rides like a much lighter bike, but when I'm used to 275-325 pounds at the curb, 450-500 pounds wet weight sounds like more than "just slightly heavier." 

The 701 is the bike my friend bought during the summer of 2016. That winter he had a hip surgery and asked me to exercise the bike periodically to keep the fluids circulating and the battery topped off while he recovered. Unfortunately, life threw him a curveball, and he ended up with limited range of motion in that hip, and therefore couldn't lift that leg very high.  Sometime around the beginning of 2018, he sat me down and said he wasn't sure he wanted to keep making payments on a bike he couldn't ride, and offered me a sweetheart deal to buy him out, since he'd rather his baby go to me than some random Joe.

He had already added a titanium Wings muffler, aluminum skidplate, and Perun Moto rack, plus Mosko Moto bag system. I added all my usual upgrades: the fairing/adjustable windshield/headlights from Britannia, tubeless supermoto wheelset, heated grips, Fisher comfort saddle, voltmeter, and Shorai lithium-iron battery.

It has been my go-to bike, and is the most versatile enduro/supermoto/commuter/flyweight backroads touring bike I can imagine. I don't seek out gnarly single track deep in the woods, and I like being able to ride and pass safely at 80 or so on the interstate, but I'm not doing that for hundreds of miles in a single day.

I didn't like way the Mosko Moto bags sat on the bike, nor the fiddly 80-bajillion features/configurations of them, so I went back to my old standby Giant Loop bags; simple, big comparents (with external cinch straps for smaller loads) durable, and local. I also added lowered, oversized, rubber-insert Fasst Company footpegs.

More recently, as I've continued to pile the miles on the 701, I got tired of the pegs. I love the slightly lowered and back position (I'm 6'2".) They are just too wide, and as an urban commuter, I found myself frequently wanting to put my foot down right where the peg hits my inner calf. Spacing my foot further outboard, or further forward/back felt unnatural while stopped, so I went to the smaller Fasst rubber-insert pegs, which are slightly oversized and stock height. I kept my dropped brake pedal tip, as I like the position.

The only reliability gripe on the bike is the instrument cluster. I've been through three of them, and all got ruined by water intrusion during rain (!!) and consequently internal shorting out. I bought a Trail Tech Vapor for it, but never put it on, in part because I would need to keep the stock gauge to keep things like the low fuel warning light...which seems like it might be useful somehow. The current gauge is wrapped in several layers of electrical tape over everything but the screen and is holding up so far...

I added the Perun Moto rack extension to make it more useful for carrying loads that aren't bags, like odd shapes with a bungee net or stretch straps.

The sharp-eyed may have noticed the new seat cover and graphics, the final realization of a long-term aesthetic idea in my head.

Other recent developments with the 701:

The color-matched seat cover looks awesome, but is too slippery, and with the taller pegs and bars, a taller seat might be nice. I tried a spray-on saddle tack and mostly just made my riding suit sticky and really dirty! I'll probably tackle the reprofiling and recovering myself this time as Fisher won't do a pattern to match my graphics (he says it looks better to do a random squiggly accent stripe) and the decent local upholstery shops are booked out 3-6 months, and seem reluctant to use my supplied gripper-type materials, or insist on supplying their own, but have a way lower bar than mine regarding a color "match." i.e. royal blue and lemon yellow look just fine as a match for my navy blue/neon yellow graphics. Or they say that a color match doesn't exist, but somehow I'm able to buy a near perfect color match with a few minutes searching online. 

I added taller Fasst Flexx bars; and they are an awesome upgrade for reducing vibration and increasing comfort.

With the taller bars, the hydraulic line was marginal for length, so I got a custom braided one from Goodridge, plus an Oberon slave cylinder and an Aurora Rally two-piece case saver which allows independent service of clutch slave and front sprocket. The clutch seems to mostly be working fine, but given that these bikes have issues and recalls with the stock slave cylinder, I'm going to upgrade while I'm in there. I haven't installed yet, but want to as I rerouted the existing line and left it loose in a couple spots to make it work.

I added Stealth Mirrors in addition to the stock mirrors...never too much visibility behind, especially at stoplights! They hang down so need to move an elbow out of the way, and are slightly convex, but I don't to rely on them alone as they are small and convex.

I scored a deal on a lightly-used Trail Tech Voyager Pro GPS/gauge, which I will be mounting in addition to the stock gauges. I'll finally have a tach! I can finally reconcile the mileage from all the additive failed odometers! I'll have ambient temp and coolant temp readouts! I'll have trail GPS tracks.  (It is primarily an off-road system, not a city street nav system, which is perfect for me.)

I've always had ABS issues when swapping to the supermoto wheels and riding at higher speeds. I tried all kinds of things, swapping wheels, rings, sensors, recalibrating the speedo, trying different 17" tire sizes. No avail, ABS still shuts off after a minute or so at highway speeds.  I finally found a dude (Ian C on the advrider forums) who makes custom ABS tone rings, and bought some for my supermoto wheels.

When installing the Voyager Pro, I will finally be installing the new Britannia dashboard I bought a while ago to redo a few minor things I don't like about the layout and wiring from my first go around after living with it for years. 

The big issue with the Husky lately (and the reason I'm not riding it now) is that the stator burnt out!

I wish I'd caught it before ruining one (and possibly two) batteries, but hey, live and learn! 

I am going to upgrade the regulator rectifier, as well as replace the stator, which unfortunately is backordered until who the berkeley knows when. I managed to buy one that is supposed to be lightly used, which should show up early this week, so we will see...

Thankfully the work needed for this repair ties in nicely with my dashboard and wiring upgrades, and should enhance future reliability. 

Yeah, the Aprilia is 450lbs wet, so probably 75lbs more than my 690, even when I have both fuel tanks full.  That adds up off road for sure, especially when you're at 12-13k ft above sea level. 

You're going to want to upgrade your fuel filters, check out my post on them in my 690 thread.

I took the bike out yesterday to meet a friend, it's SO much fun!  Just a total hooligan around town....

docwyte said:

You're going to want to upgrade your fuel filters, check out my post on them in my 690 thread.

I took the bike out yesterday to meet a friend, it's SO much fun!  Just a total hooligan around town....

Thanks for the tip; I'll check it out! I've got about 12K miles so far without fuel filter issues, but I'm all for upgrading to help prevent future issues. The bike is ridiculously fun around town, definitely makes one think hooligan thoughts. 

I started gathering parts to repair the stator and upgrade the system while I'm at it, and it will also be the perfect excuse to redo a couple things I've wanted to redo for years, but haven't yet, namely the layout of the dash/accessories and the wiring from the battery forward to the dash. I've already got the parts for the dash/wiring project.

On the charging front, I ordered a new stator and the gasket for the side cover, only to find out both are backordered, and the stator with no ETA!  I also decided to upgrade the regulator rectifier, so I ordered a MOSFET one from Roadster Cycle, a FH020AA. This upgrade should improve the health of the whole system and help the stator last longer with more precise control and less heat than the original shunt-style unit. The FH020AA also fits in the stock location and has the bolt holes in the same spot as stock.

I don't buy into the "you can never trust a stock harness and therefore should hardwire your new stator and R/R directly to each other and the battery with brand new wire to avoid suspect wiring or a dodgy connector" school of thought popular in some parts of the motorcycle electrical upgrade corners of the internet. Uhhh...you guys know you can check wiring and connectors with a careful visual inspection and a multimeter, right?  If the stock harness or connectors have issues, wiring, terminals, and connectors can be replaced/rebuilt as needed, and down the road things will be serviceable by unplugging a connector instead of having to cut apart the wiring harness, but to each his own I guess. 

Back to the stator. Options seem to wait for weeks/months/? for the backordered genuine one from Europe-$149, shop used-$75-175, see if the burnt one can be rewound-$80-300ish? if even possible, or buy an aftermarket new one of unknown provenance-$160-165ish.

I ended up deciding to keep the genuine one on backorder while also shopping used. Found a low-mileage one on eBay (listed as Svartpilen 701, but part numbers interchange) for $80. The other used ones listed on eBay as 701 Enduro/690 Enduro seemed to be $130-160ish, so I bought the $80 used one. As of today I have all the parts needed except the gasket, which is still on backorder.

Im trying to get as far as I can into other work planned while I've got things apart and am waiting on parts. Much of this was already in hand and waiting for my next teardown, and will be exciting to get on the bike:

-Aurora Rally two-piece case saver/sprocket cover-allows sprocket or clutch slave service without pulling the entire part.

-Oberon clutch slave

-Custom longer clutch line

-Clutch and brake bleeds

-Oil/Filter/screen change with oil analysis

-Really thorough header clean and polish

-Trail Tech Voyager Pro wiring and install on the dash

-Airbox clean and air filter change

-ABS tone ring install

-Front axle slider/spool install

New and old regulator side-by-side.

Accessory wiring to the battery which will be integrated into the harness more cleanly.

Wiring inside the fairing (on the backside of the dash) as it was. I'm still reasonably proud of how organized I was with this layout, but adding GPS and moving stuff around will require some changes, and I'll probably attempt some small improvements while I'm at it.

Old wiring removed and ready for the new dash layout work to begin.

I've been surprised at the lack of parts for our platforms.  I mean, KTM has been making the 690/701 since 2008 and many of the parts are the same for the entire run.  When I thought I needed a new radiator last Fall, none were available.  A radiator.  On a moto that's been made for 15 years and is still in production.  Seriously?  Thankfully my friends son welded the hole in mine up...

Fuel filters and fuel pump on this bike are seriously crappy.  The Mahle plastic filter right after the pump likes to split.  There isn't a pre filter before the fuel pump and it can die from sucking in garbage.  With 12k miles on the fuel pump, on the factory filters I'd probably just swap in a Quantum fuel pump (lifetime warranty!) at the same time I upgraded all the filters.  I added a Profill tea bag pre pump filter, replaced the Mahle plastic filter with a Best Dual Sports filter, then put a Golan filter to replace the tiny one in the fuel injector line.

Have you checked the valve clearances yet?  They're due every 6k miles...

Well, I have everything I need for the stator replacement except for the gasket for the cover. When I ordered said gasket in March, the estimated date to be back in stock was early April. No update for the one I have on backorder, and nothing has shipped. I figured maybe I'd go aftermarket so I can get riding. 
 

I plugged the KTM/Husky part number into eBay, Google shopping, etc. Nothing available on this continent. Try searching Athena Gaskets. Nothing. Try searching "690 stator gasket." Nothing confirmed in stock I can buy with confidence. Try searching "690 ignition gasket." Nothing confirmed in stock I can buy with confidence. Try searching the WPS catalogs, both street and dirt in both engine parts and in electrical parts. Nothing! Their dirt catalog doesn't contain any KTM models bigger than 500cc, nor any Husky models bigger than 501. Their street catalog has the 640 models (last made in 2007) and then...nothing. Husqvarna doesn't even exist in the street catalog!

One would get the impression this engine is some super-rare, extremely limited hen's tooth, but it has been featured in something like a dozen KTM, Husky, and GasGas dual sport, supermoto, and street bike models from 2008-2023. I'm just amazed I can't buy an OE or an aftermarket gasket for this thing to complete my repair. 
 

It seems ridiculous, but the solution might be to order one from Europe, pay 4x-6x the price of the gasket for shipping, and wait a couple weeks for it to show up. 

Have you tried Rocky Mtn ATV/MC?  Asked your KTM dealer to do a nation wide dealer inventory search for it for you?

So let's say you're in the market for a used supermoto. For equal money and similar miles (less than 13,000 miles). 2011 Husaberg FS570 or 2009 Yamaha WR250R?

docwyte said:

Have you tried Rocky Mtn ATV/MC?

Nothing at Rocky Mtn. AOMC is where I ordered it last month and still have it on backorder. My local KTM dealer isn't very convenient and I haven't had good experiences there.  Thanks for the ideas, though! Last night I bought an aftermarket one from a UK seller on eBay, $5 gasket and $20 shipping. It will be a race to see which arrives first, the eBay UK one or the indefinite backordered genuine one. 

clutchsmoke said:

So let's say you're in the market for a used supermoto. For equal money and similar miles (less than 13,000 miles). 2011 Husaberg FS570 or 2009 Yamaha WR250R?

Experienced rider? Do you find parts-hunting a fun challenge? High performance weekend fun bike? FS570

If no to any of the above questions, or if you want a daily rider, WR250R. I haven't ridden/owned one, but a very trusted buddy of around 25 years (and really experienced rider) says the Yamaha punches way above its weight.