Kawasaki Z250SL users

[alx123]

Any Z250SL users here? Highly unlikely as this 250 is not that common here, I barely see anyone (even Thais) riding it..

 

Anyway, if anyone owns it here as well..Let's discuss anything about this bike on this thread. Accessories, mods, reviews, technical stuff, etc..

 

 

[Damrongsak]

Is the engine the exact same as the KLX250? 

[alx123]

Looks like it, same bore X Stroke. Although a little more horsepower with 27hp @ 9700 rpm vs the 21hp @ 7500 rpm of the KLX. 

 

[taninthai]

19 hours ago, alx123 said:

Looks like it, same bore X Stroke. Although a little more horsepower with 27hp @ 9700 rpm vs the 21hp @ 7500 rpm of the KLX. 

 

Ok ..I better not try to race one if I’m on my crf then????????????

[Damrongsak]

23 hours ago, alx123 said:

Looks like it, same bore X Stroke. Although a little more horsepower with 27hp @ 9700 rpm vs the 21hp @ 7500 rpm of the KLX. 

 

There's a relatively simple mod for the KLX 250 (at least older ones) which involves changing the camshaft timing. Seems that the mod will yield 25 HP.  Maybe the Z250SL was tweaked like this.

 

And apparently there were various versions of the KLX 250 that had as much as 30-32 HP.  Maybe those were pure dirt bikes.

 

https://www.kawasakiforums.com/forum/klx-250s-71/klx-250-300-camshaft-mod-marcelino-35904/page2/

[alx123]

14 hours ago, Damrongsak said:

There's a relatively simple mod for the KLX 250 (at least older ones) which involves changing the camshaft timing. Seems that the mod will yield 25 HP.  Maybe the Z250SL was tweaked like this.

 

And apparently there were various versions of the KLX 250 that had as much as 30-32 HP.  Maybe those were pure dirt bikes.

 

https://www.kawasakiforums.com/forum/klx-250s-71/klx-250-300-camshaft-mod-marcelino-35904/page2/

Yes, changing the camshaft's profile and maybe a little tweak on the FI can produce a little bit more of hp. 

[Damrongsak]

Here's a really naked Z250SL. 

 

 

 

 

[alx123]

That gives another meaning to a Naked motorcycle. ???? 

 

Question.

 

Given that this is a single cylinder 250, the bike vibrates a little at speed above 100 kph. It isn't that bad actually, except that it is causing a small buzz on the mirrors that the vehicles behind me aren't clear as it should be. Iv'e read that you can actually add weights inside the mirrors to help with the buzzing or/and install weighted bar ends to reduce vibrations of the handlebars. 

 

Iv'e never had this problem on my PCX. Any thoughts on what should I try to remedy this? 

 

Maybe try aftermarket mirrors?

 

Note to self:  next bike should be i4. 

[papa al]

Maybe tire balancing weights

on backside of mirrors, the adhesive kind?

Dyna-beads in tires.

Aren't bar-end weights factory installed?

[alx123]

2 hours ago, papa al said:

Maybe tire balancing weights

on backside of mirrors, the adhesive kind?

Dyna-beads in tires.

Aren't bar-end weights factory installed?

Yes, there are bar-end weights installed. I thought one can buy a much heavier aftermarket ones, no?

Yes, Iv'e read weights on or inside the mirrors might help. I'll try these and let's see what happens.

 

[papa al]

Getting weights inside the mirror housing might be challenging.

 

[Damrongsak]

One possibility for the mirrors - a vibration isolator with the rubber dampener:

 

 

I don't know if you could drill a small hole in the mirror housing and pour in some lead or tungsten shot, similar to a dead-blow hammer.

[VocalNeal]

On 11/14/2019 at 9:17 AM, alx123 said:

Iv'e read that you can actually add weights inside the mirrors to help with the buzzing or/and install weighted bar ends to reduce vibrations of the handlebars. 

Proof of concept. Go to any tyre store and ask for a couple of 5g stick on balance weights. Stick them (double sided tape 7-11) in the top corner of the mirror?

 

[papa al]

5 hours ago, VocalNeal said:

Proof of concept. Go to any tyre store and ask for a couple of 5g stick on balance weights. Stick them (double sided tape 7-11) in the top corner of the mirror?

 

Curious; 3 questions:

1. why add double-sided sticky-tape

to weights that already are stick-on by design.?

b. why attach to mirror rather than to the back side of the unit.

Seems like would block the sweetest part of the mirror-glass.

4. why 5-gram weights. rather than 10 gram weights.?

[papa al]

13 hours ago, Damrongsak said:

I don't know if you could drill a small hole in the mirror housing and pour in some lead or tungsten shot, similar to a dead-blow hammer.

This sounds like a good idea.

Where can shot be sourced in Thailand?

[ktm jeff]

1 hour ago, papa al said:

This sounds like a good idea.

Where can shot be sourced in Thailand?Fishing tackle shop. Or maybe shotgun cartridges. Asking someone to shoot you may be more of a problem in the long run.

 

 

[papa al]

Just returned from fishing tackle shop.

They had a little plastic container with about 8 sizes of split shot in it.

About 8 each, sizes about 2mm thru about 10mm.  B70.

Didn't buy.  

Shotgun birdshot would be good,

but don't know any skeet shooters.

 

[Damrongsak]

Lazada has the small split shot in packs of 100. 

 

This fellow made his own "shot" just by melting lead over a bucket of water.  He could have done it from a greater height to get the shot rounder.  https://www.instructables.com/id/Wooden-Dead-Blow-Mallet/

 

There are Youtube videos about making real shotgun shot.  Pretty interesting the way they drip it through various sized drip nozzles to control the size.  https://www.youtube.com/results?search_query=making+shotgun+shot

 

You could get a spool of solder of appropriate diameter and just use cutters to nip it into very short pellets. 

 

[alx123]

On 11/16/2019 at 1:28 AM, Damrongsak said:

One possibility for the mirrors - a vibration isolator with the rubber dampener:

 

 

I don't know if you could drill a small hole in the mirror housing and pour in some lead or tungsten shot, similar to a dead-blow hammer.

This looks interesting. On a mission to find one and report back here. 

 

Also, I just checked the tire pressure for the first time since I bought the bike (newbie mistake), both tires are way under inflated that it is actually a factor on the vibration I am feeling. Nevertheless, inflating the tire to its correct PSI really did improved the ride, albeit the buzz at higher speed is minimized but is still there. 

 

I will try doing some of your suggestions here. 

[alx123]

On 11/16/2019 at 9:41 AM, VocalNeal said:

Proof of concept. Go to any tyre store and ask for a couple of 5g stick on balance weights. Stick them (double sided tape 7-11) in the top corner of the mirror?

 

This will be my last resort if nothing works. I can easily just paint these black to match the mirrors housing color. 

[VocalNeal]

As I said proof of concept. I'd just leave them the natural. If anyone notices they will ask and then, assuming it works, you can be clever.

 

If you stick them on the glass they will be easier to remove if they don't have the desired effect.

[papa al]

Dyna-beads will eliminate the main cause of vibration at higher speeds.

[Imperfectly balanced wheels]

Weighted mirrors might mitigate the effect of vibration.

Which is better ...?

 

[papa al]

6 minutes ago, VocalNeal said:

 

If you stick them on the glass they will be easier to remove 

papa would expect the exact opposite.

[alx123]

don't want them in the mirrors as I feel like every surface of the mirrors are useful for visibility of cars behind me. 

 

as for dyna beads, as kinda reading about it and that is it useful for balancing wheels but will they work on the vibrations as i think the one on the Z250sl is engine related , rpm related (single cylinder problems)? 

[papa al]

On 11/14/2019 at 9:17 AM, alx123 said:

the bike vibrates a little at speed above 100 kph.

alx123 also said:  

"i think the one on the Z250sl is engine related , rpm related"

------------------------------------------

So which is it?      High speed or some rpm?

 

If you pull the clutch at speed, does the vibration stop?

[doubtful]

Do mirrors vibrate at low-speed/low-gear at some rpm?

??

When wheels and engine resonate at the same frequency or harmonic,

The vibration is the worst.

[alx123]

13 hours ago, papa al said:

alx123 also said:  

"i think the one on the Z250sl is engine related , rpm related"

------------------------------------------

So which is it?      High speed or some rpm?

 

If you pull the clutch at speed, does the vibration stop?

[doubtful]

Do mirrors vibrate at low-speed/low-gear at some rpm?

??

When wheels and engine resonate at the same frequency or harmonic,

The vibration is the worst.

hmm, make sense. honestly, im not sure now. i will need to try again as i might be shifting right before certain rpm in lower gears therefore no vibes, unlike on 100kph above im mostly at 6th.

[papa al]

In papa's experience, the unbalanced wheel at speed is a biggie.

The faster you go,

the worse the vibes.

True on a 150cc bike, or 18-wheeler.

Luckily, can be easily remedied 

if ya gots da balls.

Beyond the mirror problem, eliminating vibration decreases suspension wear, improves performance and fuel economy.

[VocalNeal]

On 11/18/2019 at 9:42 AM, papa al said:

papa would expect the exact opposite.

No. because you can if necessary scrape the glass with a razor blade or use solvent to loosen the tape. 

[papa al]

1 hour ago, VocalNeal said:

No. because you can if necessary scrape the glass with a razor blade or use solvent to loosen the tape. 

If applied to the plastic back, just pop off with thumb-nail.

No sharp instrument nor dangerous chemical required.

Much easier.!

[Damrongsak]

Wheel weights are tacky.  Glue some of these on: