Clutch overheating? - Sportbike Forum: Sportbike Motorcycle Forums
LinkBack Thread Tools Display Modes
post #1 of 9 (permalink) Old 08-29-2005, 08:12 AM Thread Starter
Join Date: Mar 2004
Posts: 8,798
Clutch overheating?

Well at least thats what I think is happening. Let me give the rest of the story.
Me and a few buds go riding sunday. Pretty soon it turns into a whole lot of stop and go traffic, and its about 105 outside. Since da police was out in force, we decided against hitting the twisties, and instead went to check out "wheelie road" which ended up being a mile long drainage ditch. I suppose thats as good a place as any, no traffic what so ever, no houses near by. My only concern is the traction on a cement slab, but it proved to be alright. The first few runs where fine, but soon afterwords things started being a little wierd. The rev's were coming up too high, and the front wheel wasnt coming up high enough. The only thing I could figure out was a slipping clutch. After we left, the bike cooled down, and everything was fine again.
So did my clutch overheat? how do I keep that from happening?
Clutch is oil cooler right? and kawi's cool the oil with the radiator... So maybe add another oil cooler? use different grade oil? water wetter in the radiator?

Vash is offline  
Sponsored Links
post #2 of 9 (permalink) Old 08-29-2005, 09:16 AM
Strength and Honor
kanwisch's Avatar
Join Date: Oct 2002
Location: Central IN
Posts: 6,144
Wouldn't water wetter impact the viscosity? I'd probably stay away from that and look at alternate oil cooling options. But since you already have an oil cooler, it seems awfully unlikely it can't handle the existing loads

You're not using the clutch to stunt, are you? If not, it seems odd that the clutch would be an issue but the description you give certainly points that way.

Is it possible that while stunting the oil can move through the clutch and drain into the oil sump, thus not being recirculated properly? Is your oil pump even able to pump while standing one up? EDIT: This is a silly question. You'd see it as a warning. So does the clutch keep oil level by flow restrictor or simply by having an opening at a certain level? If the latter, maybe the stunting allows too much of the oil to drain out.

Basically if you're looking at greater heat transfer, changing oil weight might help by dropping down a bit, esp if you don't run it with that in the really cold months (in Texas: ). Since it went away I'll figure you don't have the oil cooler sludged up and that the fins are clear and not overly screwed up. A more expensive alternative would be a larger oil cooler, but again I find it hard to believe that stunting is really driving the temp that high when you've already got external cooling going on!

SportbikeWorld Supermoderator

Dragging knee is for the track, and dragging tail is for the lot. --Kane Friesen

When you're in a car, you're watching a movie; when you're on a bike, you're in the movie. --Robert Pirsig

Identity theft is not Fun

Last edited by kanwisch; 08-29-2005 at 09:19 AM.
kanwisch is offline  
post #3 of 9 (permalink) Old 08-29-2005, 09:30 AM Thread Starter
Join Date: Mar 2004
Posts: 8,798
I wasnt quiet clear. Unlike other companies, kawi doesnt use a seperate oil cooler and radiator. Instead they have a water jacket that mounts next to the oil filter. The oil is thus cooled by the passing water.
My other suspesion is the new syth oil I put in my bike. I coudlnt find red cap for the life of me, so I went with something else (cant remember now) but made sure it mentioned nothing about friction modifiers. A few days after the oil change the clutch did something wierd. As I started the bike, gave it enough time to warm up a tad, while putting on helmet, jacket, etc. I got on and started feathering the clutch (just normal everyday start) as the clutch was coming out, I wasnt moving forward untill, it lurched forward all at once, and stalled. The sort of thing you'd see from not knowing how to work the clutch, except I consider myself above that mistake. Well I didnt think too much about it, untill the same thing happened again the next day, again with the bike just warming up. This time I managed not to stall it. Ever since then the clutch has been acting fine. So two strange occurances. I thought my cable might be catching, but I just oiled it. Maybe I gunked it up a tad.
Anywho, back to wheelie road. Wheelies are hard on the clutch, more so than daily driving. I mean, rev to 6k (maybe? I go by sound) and feather the clutch in. Over and over. To make things worse its a slipper clutch, so it slips a tad on engine braking and downshifts, warming it up even more.
At first I thought I simply wore out my clutch due to too much abuse. I was disappointed that it would happen on a 4 mo old bike, but let it go. Then the clutch started working fine again once cool.
So my solution would have something to do with keeping the oil cooler. Water wetter is supposed to drop the radiator temps, and thus the oil. There is also something called engine ice, which is supposed to do the same thing.

Vash is offline  
post #4 of 9 (permalink) Old 08-29-2005, 09:35 AM
Join Date: Oct 2003
Posts: 434
Two things,

1. When the bike is run hard for extended periods of time, oil viscocity can break down, just like at the track. In the summer when engines run hotter, you can go up to 20-50, i don't do it because it is harder on cold starts, and so on. Some oils are worse than others about breaking down.
I have used many dif oils, still swear by castrol 10-40, best oil i have used.

2.Improper clutch adjustment, slipping clutch, both of these will build up heat, you may be in the first signs of new clutch time. I put new clutch in at 3500 miles, Barnett Kevlar+Heavy Springs+Castrol 10-40= happy clutch, no slip.
izzybo69 is offline  
post #5 of 9 (permalink) Old 08-29-2005, 09:38 AM
Join Date: Oct 2003
Posts: 434
SYNTHETIC!, Trust me dood, that is worst thing you can do for clutches, sure it may be fine for everyday use, but on the track, stunting, dragracing, etc. Its no good. Been there, done that. never again.
izzybo69 is offline  
post #6 of 9 (permalink) Old 08-29-2005, 09:40 AM Thread Starter
Join Date: Mar 2004
Posts: 8,798
I got about 4-5k miles on the bike, less than 1k on this oil. I'll change to non synthetic and see how it works out

Vash is offline  
post #7 of 9 (permalink) Old 08-29-2005, 09:43 AM
Join Date: Oct 2003
Posts: 434
You should notice huge dif., but the damage may already be done.

Just out of curiosity, is there more involved in replacing the clutch in your bike, being a slipper clutch?

Just wandering.
izzybo69 is offline  
post #8 of 9 (permalink) Old 08-29-2005, 09:58 AM Thread Starter
Join Date: Mar 2004
Posts: 8,798
Never done it, but there shouldnt much more to it. Just a set of ball bearings in the back

Vash is offline  
post #9 of 9 (permalink) Old 08-30-2005, 09:24 AM Thread Starter
Join Date: Mar 2004
Posts: 8,798
I figured out half the problem. The strange behaviour of the clutch on start up, sometimes.
Seems the I didnt correctly route the clutch cable when I was puting my bike back together. It tightens up when the bars are turned all the way left, and can catch on some tab inside the fairing. When it does, it doesnt behave quiete right, untill the plastic tab releases.

One problem solved... I'm still chunking the other one to over heating. Stunting seems to really mess the bike up like that. Overheated clutch, brakes....

Vash is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Sportbike Forum: Sportbike Motorcycle Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome