1999 ATK 250LQ

[brademan76]

20260419_172729.jpg (4.54 MiB) Viewed 2484 times

Just got this bike and am ordering parts and thinking on things to do with it. It didn't come with a carb, luckily I have a couple pwks from my kdxs that I've replaced with lectrons, so I plan to use one of those while I decide if I like the bike enough to put a SC or Lectron on it.

While going through things, the piston was wrecked and had transferred a good amt of aluminum to the cylinder but I think the cylinder is ok. Either way it's getting sent off to Ted Boyko to do some work on it to improve bottom end as this 250 rotax engine is known for it's top end with an anemic bottom. The adjustable exhaust valve is interesting and I'm looking forward to playing with that.

The linkage-less rear suspension interests me for its simplicity especially for access to easily pull off and adjust as needed.

Opinions Needed-
I've torn apart the shock to rebuild and got exploded parts diagram from ohlins as there was zero information online on this model shock as it seems one off for this particular bike. The guy from ohlins said to use an ohlins shock oil that is 28cst, which seems heavy vs the Showa ss-7 (5w) @15.7cst that I use in my KDX shocks. I ride tight single track/enduro mainly, no mx track. Should I just stick with my 5w or move closer to basically a 10w?

I'm also excited about feeling the 46mm Paoili "blue steel" (essentially KYB) forks.

Definitely a quirky bike but I'm looking forward to getting it in good shape and seeing how it rides.

[billie_morini]

Brad, so very cool! Hope aggravations are minimal & the bike becomes functional with ease.

[Chuck78]

Very unique bike! A local guy near me has or formerly had an ATK 4-stroke, which very oddly was a motorcycle engine that used a timing belt!



Wow, the clutch and the kicker are on the left side!

[brademan76]

Very unique bike! A local guy near me has or formerly had an ATK 4-stroke, which very oddly was a motorcycle engine that used a timing belt!



Wow, the clutch and the kicker are on the left side!

Yeah I like the idea of the kicker on the left so I can keep right foot on rear brake in steep stuff!

LMK your thoughts on getting a pwk for this bike.

[Chuck78]

Yeah I like the idea of the kicker on the left so I can keep right foot on rear brake in steep stuff!

That is a good thing with being able to keep the foot on the brake! The front brake just doesn't suffice when you're pointed up a steep hill and stall out, the bike just slides. I've had very slight thoughts of putting a second hand brake lever on the handlebars tied to the rear brake pedal for this very reason! It happens infrequently but when it does happen, you certainly wish you had a rear hand brake control!

LMK your thoughts on getting a PWK for this bike.

Well, I don't even know what carburetor is on it currently, but I'm certain you could fit a PWK to it, and most likely a PWK 36 Air Striker would work well, but you would most likely need a long body version of it. If the existing carburetor is smaller dimensionally on the intake spigot and air box bell, then a KDX application PWK 35 Air Striker would be the one. That's going to cost you $430 or more though to get a genuine one that is guaranteed to be genuine.

And then the jetting trials and tribulations will begin....
A SmartCarb SC3 36 might do quite well if you have an extra couple hundred bucks on top of that, they are $599 to $649 new.

[brademan76]

Yeah I like the idea of the kicker on the left so I can keep right foot on rear brake in steep stuff!

That is a good thing with being able to keep the foot on the brake! The front brake just doesn't suffice when you're pointed up a steep hill and stall out, the bike just slides. I've had very slight thoughts of putting a second hand brake lever on the handlebars tied to the rear brake pedal for this very reason! It happens infrequently but when it does happen, you certainly wish you had a rear hand brake control!

LMK your thoughts on getting a PWK for this bike.

Well, I don't even know what carburetor is on it currently, but I'm certain you could fit a PWK to it, and most likely a PWK 36 Air Striker would work well, but you would most likely need a long body version of it. If the existing carburetor is smaller dimensionally on the intake spigot and air box bell, then a KDX application PWK 35 Air Striker would be the one. That's going to cost you $430 or more though to get a genuine one that is guaranteed to be genuine.

And then the jetting trials and tribulations will begin....
A SmartCarb SC3 36 might do quite well if you have an extra couple hundred bucks on top of that, they are $599 to $649 new.

Sorry- I meant "jetting" a 38mm PWK carb for it- one that I already have (taken off a KDX replaced by a lectron). Originally the ATK had a 38mm mikuni.

[billie_morini]

Very unique bike! A local guy near me has or formerly had an ATK 4-stroke, which very oddly was a motorcycle engine that used a timing belt!

Wow, the clutch and the kicker are on the left side!

My 6 Moto Morini all had timing belts! (Heron heads, too)