quick question before I head off to work

[walty87]

Recently I replaced the clutch plates on my 12' ninja 250.

There's no more slipping! But I've noticed that I have lost some top speed? I used to redline in 6th and be slightly above 100mph on the speedo. Now I'm barley reaching above 90mph at redline in 6th.

Any idea's on why this could be? It's not a huge deal or anything... But i'd like to know what could be causing this?

[Motofool]

Your clutch is slipping at high temperatures of the oil.

It may get better when the new disks break-in more.

[walty87]

Could it be cause I'm using crappy oil? or a different one rather then the one the kawi dealer uses?

[broilmebk]

Just out of curiosity. What was the reason for changing clutch plate? I see you have a 2012

[Motofool]

Originally Posted by walty87

Could it be cause I'm using crappy oil? or a different one rather then the one the kawi dealer uses?

Don't know what crappy oil is; but any oil of the recommended grade works OK, except the Energy conserving (EC) oils, which contain bad staff for the friction of the disks.

http://faq.ninja250.org/wiki/Preferred_Brands

Also, verify that the clutch lever has the proper free play.

[Stingray1000]

Originally Posted by broilmebk

Just out of curiosity. What was the reason for changing clutch plate? I see you have a 2012

Good question!

[alex.s]

Originally Posted by walty87

Recently I replaced the clutch plates on my 12' ninja 250.

There's no more slipping! But I've noticed that I have lost some top speed? I used to redline in 6th and be slightly above 100mph on the speedo. Now I'm barley reaching above 90mph at redline in 6th.

Any idea's on why this could be? It's not a huge deal or anything... But i'd like to know what could be causing this?

is the bike bouncing off the limiter at 90? or just stops going faster? if it really is bouncing off the limiter and you have stock gearing, then the "90mph" reading is incorrect. if you arent bouncing off the limiter, and are in 6th with stock gearing, 90mph shoould be about 11krpm. if you cant get higher than that in 6th, you might have tuning issues like improper fuel ratios, or incorrect valve adjustment... or a vacuum leak, or some other air leak, or a janky chain, or messed up bearings.

[NJ Ninjette]

Originally Posted by broilmebk

Just out of curiosity. What was the reason for changing clutch plate? I see you have a 2012

+2

[alex.s]

he posted earlier. clutch went out from too many wheelies.

[walty87]

When I start to red line 13k 14krpm in 6th I'm going about 90mph. I'm still gaining speed, but I usually let off and don't keep going.

I believe my clutch is is adjusted loosely, I have quite a bit of play in the lever...

My clutch went out before like what said by alex, I did some wheelies \ burnouts, but also the main reason I think it that I was riding around with my clutch adjusted incorrectly and it was way too tight. I think it was constantly engaged and burnt out fast.
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[headshrink]

Did the replacemet plats get an overnight bath in oil so swell properly?
Upgraded clutch springs might help too.

[walty87]

They didn't. Didn't know that had to be done.
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[headshrink]

Originally Posted by walty87

They didn't. Didn't know that had to be done.
Posted via Mobile Device

Assuming everything is adjusted properly, this would be my guess...

[Motofool]

Originally Posted by walty87

..........My clutch went out before like what said by alex, I did some wheelies \ burnouts, but also the main reason I think it that I was riding around with my clutch adjusted incorrectly and it was way too tight. I think it was constantly engaged and burnt out fast.

Springs loose their strength when they are forced to work at high temperatures, such as caused by constant slipping.

If you didn't replace the springs, that may be the cause of the current slip.

The current slip will deform the new metal discs (they are new, right?) and will make the springs weaker.

Over-heat and contaminants are the two enemies of clutch health.

If the engine's rpm / speed ratio has changed that 10% for worse, clutch slip is happening.

[walty87]

Thanks guys.

Should I buy new springs and replace them?

Or should I just wait and buy a new clutch and new springs and just replace them when it gets worst?
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[Motofool]

Before doing anything, I would keep an eye on the rpm and speed in order to see if the problem improves or worsens.

Best luck!

[headshrink]

I agree that observing it for a short while longer may lead to a more accurate diagnosis. Since the clutch wasn't pre-swelled in an oil bath prior to install, things may tighten up as it swells inside the bike. I haven't a clue, however, if it will do so in a way that puts uneven pressure on the springs......