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james250ninja
February 11th, 2013, 08:03 AM
how do u like the new 300 ninja do u see any diffrent from the 08-12 to the newer ninja...

have u ever come acroo an 87 ninja 250 the first ones...been dying to find one of those.

i onwed the older gens and the 08 style..fun bikes

alex.s
February 11th, 2013, 10:41 AM
i think they are cool. there are differences from the 08-12 to 13-, yes.

i haven't seen an 87 personally.

ninja 250... best bike in the world.

Alex
February 11th, 2013, 01:36 PM
I think all of the Alex's should chime in. :)

My initial review of our 300 is somewhere here in this section, look for threads started by me and it should pop up...

Short answer, I really like the new bike, it's just a little better in just about every area from our '08 250. The only immediate downside that I noticed was that they downgraded the front brake pads so much that they felt quite weak compared to what I was used to. With a pad change and some bedding in, they are back to what I would have expected out of the box.

alex.s
February 11th, 2013, 01:57 PM
i like the way they rebuilt the bottom for the 300 engine to be more inline with their current zx motor setup. you know with a 4-section block instead of 3-section block. i also like that they are starting out with much lower compression ... i think the 300 motor could potentially be tuned to have large gains with some rebuilding

alex.s
February 11th, 2013, 01:59 PM
so... question... if the 300 is supposed to be the same bore, just stroked out, does that mean you can put in 250 pistons to get the 11 point something compression instead of 10 point whatever it is on the 300 stock?

Jiggles
February 11th, 2013, 02:37 PM
Yes

Alex
February 11th, 2013, 04:37 PM
Not sure it's that straightforward; the 300 has different conrods as well, which affect that compression ratio.

alex.s
February 11th, 2013, 05:50 PM
splitting hairs here, but it would be the diameter of the journal pivot on the crank shaft that determines the stroke length.. since the rod doesnt change shape, it is merely an offset. so technically speaking its *possible* that the 300 and 250 use the same rod and pistons... doubtful... but possible. more likely the rods would be longer to accomodate the BDC offset of the piston back to the standard minimum distance from the crank shaft (if the rod stayed the same size, at BDC you could potentially slam the piston into the crank shaft... depends on what the current minimum offset is. so if the current min is within the difference in stroke to with the larger crank, its possible the rods could be the same)

Alex
February 11th, 2013, 06:23 PM
Both of these reviews say that the pistons and connecting rods were lightened & strengthened, and they also say the the connecting rods were shortened.

http://www.motorcycle.com/manufacturer/kawasaki/2013-kawasaki-ninja-300-review-91429.html
http://www.cycleworld.com/2012/09/04/2013-kawasaki-ninja-300-first-look/

The wording is close enough that it probably came right from Kawi's tech briefing on the new model.

alex.s
February 11th, 2013, 06:42 PM
look what i found:

New 296cc Engine:

• Compact parallel-twin design offers good mass centralization for nimble handling

• Tuned to deliver smooth, step-free power with excellent mid-range and high-rpm power for effective highway performance

• New intake ports taper from 1mm wider at the throttle body to .5mm
wider at the valve seats

• New 23.6mm intake valves are 1mm larger than last year

• New cam chain design reduces friction for increased power and efficiency

• Revised 10.6:1 compression ratio allows the use of regular 87-octane unleaded gasoline and helps reduce operating temperatures

• New lighter pistons reduce reciprocating weight and feature a hard anodized coating for reduced friction and increased performance at every rpm

• Revised piston bottoms efficiently route cooling oil across underside of piston

• New lighter piston pins reduce reciprocating weight and help preserve a high redline

• New shorter connecting rods offset new longer crank throws

• New sleeveless “open-deck” die-cast aluminum cylinders are 800 grams lighter and feature a friction-reducing “T-treatment” plating

• New thicker crankshaft balancer webs help offset the new longer crank throws

• New crank journal bearings are made from a stronger alloy for increased durability

• New crank cases feature improved oil passages

• New large-volume 2.4 liter oil pan features cooling fins and better ground clearance

• New easy-to-access cartridge type spin-on oil filter helps simplify maintenance

alex.s
February 11th, 2013, 06:52 PM
been reading about the 300 clutch... its self-servo assisted clutch... does the clutch still work when the bike is off? is it just harder to pull when the engine isn't running?

Alex
February 11th, 2013, 06:59 PM
:thumbup:

Clutch isn't electrically powered. It's just that the tension/friction increases at higher revs due to its design. Allows for a lighter clutch lever pull than would be otherwise possible. At higher revs when more force is required to hold the plates together, the design takes that into account.

With similar clutches, some reviews of other bikes complain that the clutch lever feel is somewhat variable depending on where the revs are. My (destroyed) K1600GT has a similar design, and I could sense it, but it never bothered me much. I don't sense any such variability in feel at all on the 300. :idunno: