New to the forum and a quick question!
Thread Starter
Member
Squid
Joined: May 2011
Posts: 74
New to the forum and a quick question!
Hey everyone... my name is Rob and I just recently picked up a 98 Superhawk. So far just about everything is good. I changed the oil, bled the brakes/clutch and ran it for about 75 miles today. Tomorrow it's going to be plugs and coolant... wish me luck! The clutch fluid looked like straight mud and the brake fluid was probably original. The reason I bled the clutch out is because when the bike hit operating temperatures the clutch would slip in first gear so I immediately drove home and bled it. Since bleeding it the slipping is almost 100% gone. My only question for you guys is why would the clutch start to slip at rpms around 7k+? When I hammer on it the rpm gauge slips away and when I let off it ends up right about where it should be. The bike is obviously 13 years old but it has only 12k miles on it. So I'm not sure what is going on. My buddy was thinking springs but if I am going to tear it apart to replace those I might as well replace the entire clutch. Any thoughts or ideas? Thanks in advance for any input. Incase anyone is curious I picked it up for 2200$. Think I got a good deal? I felt like I did.
Thanks in advance,
Rob
Thanks in advance,
Rob
Former Superchicken Owner
SuperBike
Joined: Sep 2008
Posts: 1,607
From: Ft. Worth, TX
Senior Member
MotoGP
Joined: May 2008
Posts: 3,452
From: San Clemente, CA
You might be mistaking tire slip for clutch slip. How old are your tires? When I was running 1st generation Dunlop Qualifiers, I'd sometimes get noticeable tire slip during hard acceleration in 2nd gear.
To check for clutch slipping, give it full throttle (in a higher gear only, 3rd or 4th, so you don't loop it) from a low rpm (2000 to 2500). If your clutch is worn, that's when it's most likely to slip.
Welcome to the forum, and enjoy the torque!
Just read your post again. When you say the rpm gauge "slips", do you mean that the rpm increases, but your road speed doesn't? If that's the case, you're looking at replacing the clutch.
To check for clutch slipping, give it full throttle (in a higher gear only, 3rd or 4th, so you don't loop it) from a low rpm (2000 to 2500). If your clutch is worn, that's when it's most likely to slip.
Welcome to the forum, and enjoy the torque!
Just read your post again. When you say the rpm gauge "slips", do you mean that the rpm increases, but your road speed doesn't? If that's the case, you're looking at replacing the clutch.
Last edited by VTRsurfer; May 29, 2011 at 05:30 PM.
Thread Starter
Member
Squid
Joined: May 2011
Posts: 74
I didn't change it until after the 75.
I'm not sure but I can tell you that when I'm in the mid rpm range and give it full throttle the rpm gauge will run towards red line with little to no acceleration.
When I first bled the system it grabbed right away. On this last 65 mile trip there were points in the trip that I didn't feel the slip at all but from the way it feels it's kinda of like it comes and goes as it pleases.
End result I am going to go home and bleed the system again. I'll update tomorrow.
Thanks everyone!
I'm not sure but I can tell you that when I'm in the mid rpm range and give it full throttle the rpm gauge will run towards red line with little to no acceleration.
When I first bled the system it grabbed right away. On this last 65 mile trip there were points in the trip that I didn't feel the slip at all but from the way it feels it's kinda of like it comes and goes as it pleases.
End result I am going to go home and bleed the system again. I'll update tomorrow.
Thanks everyone!
Member
Squid
Joined: Apr 2010
Posts: 85
From: NorCal
Having air in the system will not cause clutch slip.
I agree with the oil change. Put in a motorcycle oil seeing as you have problems.
Also check that the clutch lever hasn't been changed to an aftermarket one as sometimes they don't fully disengage.
I agree with the oil change. Put in a motorcycle oil seeing as you have problems.
Also check that the clutch lever hasn't been changed to an aftermarket one as sometimes they don't fully disengage.
Thread Starter
Member
Squid
Joined: May 2011
Posts: 74
8541 was the winner of today's mystery question! haha I got home from riding a total of 100 miles(after the 75)... not 65. It was slipping throughout the entire RPM range in every gear except for 6th. It was only under heavy acceleration though. Needless to say when I bled the system out again there were air bubbles galore. After playing around a bit I got everything looking pretty and took it for another spin. I was cranking on the throttle in the first three gears and it was 100%. The answer to the oil question... I did use motorcycle oil and I picked it up at the Honda stealership. 10w-40 to be exact and DOT 4 brake fluid for everything else.
-Rob
-Rob
Senior Member
MotoGP
Joined: May 2008
Posts: 3,452
From: San Clemente, CA
Air in the system will only affect disengagement of the clutch...IE: you'll have difficulty getting it into gear.
If it's slipping you're wasting your time bleeding the system. You need a new clutch.
If you had cable clutch actuation, you could try adjusting more free play into the cable, but unfortunately with a hydraulic clutch no adjustment is possible.
The PO may have used automotive oil from Autozone, which isn't any cheaper than motorcycle oil from the Honda dealer. I use only Pro Honda 10w40, and I just turned 49,000 on the clock yesterday.
Hope you've got it solved so you can ride.
If it's slipping you're wasting your time bleeding the system. You need a new clutch.
If you had cable clutch actuation, you could try adjusting more free play into the cable, but unfortunately with a hydraulic clutch no adjustment is possible.
The PO may have used automotive oil from Autozone, which isn't any cheaper than motorcycle oil from the Honda dealer. I use only Pro Honda 10w40, and I just turned 49,000 on the clock yesterday.
Hope you've got it solved so you can ride.
Last edited by VTRsurfer; May 29, 2011 at 09:48 PM.
Banned
MotoGP
Joined: Aug 2007
Posts: 5,942
From: Lake View Terrace, CA
You know I had the same thought about air in the system until it happen to me. Can I explain it, no.
What I do know is that the bike would run fine until you really hit it and then it would slip.
Bleed the line and the problem went away.
So believe it or not air in the system can cause the clutch to slip under load.
What I do know is that the bike would run fine until you really hit it and then it would slip.
Bleed the line and the problem went away.
So believe it or not air in the system can cause the clutch to slip under load.
Senior Member
Superstock
Joined: Jan 2011
Posts: 258
From: Santa Clara, CA
You know I had the same thought about air in the system until it happen to me. Can I explain it, no.
What I do know is that the bike would run fine until you really hit it and then it would slip.
Bleed the line and the problem went away.
So believe it or not air in the system can cause the clutch to slip under load.
What I do know is that the bike would run fine until you really hit it and then it would slip.
Bleed the line and the problem went away.
So believe it or not air in the system can cause the clutch to slip under load.
Air is compressible and changes volume exponentially compared to dot3/4/5 fluids. That is if physics still apply in this universe?
(Gravity is still down, yeah?
)I don't know if the temp. would cause air to expand that much though. I'm just shooting off some ideas because I've had this exact same problem on my old VF (in conjunction with bad seal/low fluid
). Domo does make a good point though, our clutches (and most all motorcycles to the best of my knowledge) are negative pressure, meaning pressure disengages not engages (like brakes) so therefore, a problem in compression of fluid would lead to problems in shifting, not slippage.
Thread Starter
Member
Squid
Joined: May 2011
Posts: 74
One last question then my bike will be 100% on the mechanical side. Where should the temp gauge read when it's at operating temp? My needle will NOT go past the first 1/4 tick. Then again the temp out here was 60 ish. Although I was doing some really quick runs with it on some back roads and the needle tried to move towards the dead center but just wouldn't stay there. Is it possible that the thermostat is stuck open?
Senior Member
MotoGP
Joined: May 2008
Posts: 3,452
From: San Clemente, CA
You know I had the same thought about air in the system until it happen to me. Can I explain it, no.
What I do know is that the bike would run fine until you really hit it and then it would slip.
Bleed the line and the problem went away.
So believe it or not air in the system can cause the clutch to slip under load.
What I do know is that the bike would run fine until you really hit it and then it would slip.
Bleed the line and the problem went away.
So believe it or not air in the system can cause the clutch to slip under load.
I've driven cars with a broken clutch cable, and with a blown slave cylinder, by turning the starter over in 2nd gear to get it running...then no problem.
I had the fluid boil in my '86 CB700SC while riding home from work, splitting lanes in heavy traffic on the freeway, over 20 years ago. No problem shifting up and down with a completely limp clutch lever. Fortunately for me the traffic cleared up and the fluid cooled off before I got off the freeway. But when I parked it at home and touched the slave cylinder, I burned the **** out of my finger.
Senior Member
MotoGP
Joined: May 2008
Posts: 3,452
From: San Clemente, CA
One last question then my bike will be 100% on the mechanical side. Where should the temp gauge read when it's at operating temp? My needle will NOT go past the first 1/4 tick. Then again the temp out here was 60 ish. Although I was doing some really quick runs with it on some back roads and the needle tried to move towards the dead center but just wouldn't stay there. Is it possible that the thermostat is stuck open?
Senior Member
Superstock
Joined: Jan 2011
Posts: 258
From: Santa Clara, CA
One last question then my bike will be 100% on the mechanical side. Where should the temp gauge read when it's at operating temp? My needle will NOT go past the first 1/4 tick. Then again the temp out here was 60 ish. Although I was doing some really quick runs with it on some back roads and the needle tried to move towards the dead center but just wouldn't stay there. Is it possible that the thermostat is stuck open?
They run pretty cool, this isn't something to be concerned about, I run mine decently hard in typically around 80 and I never see mine get past 1/2.
Typical city and commute is around 1/4 but if you're literally sitting in traffic in 90+ it can get to have the fan kick on. I've had it happen....... twice?
Banned
MotoGP
Joined: Aug 2007
Posts: 5,942
From: Lake View Terrace, CA
With all respect Mike, you could completely remove the clutch slave and master cylinders, and you could still ride the bike, shifting up and down. the only problem would be getting it started. The clutch slave and master only act to disengage the clutch. The pressure plate, or springs, otherwise hold the clutch in solid engagement.
I've driven cars with a broken clutch cable, and with a blown slave cylinder, by turning the starter over in 2nd gear to get it running...then no problem.
I had the fluid boil in my '86 CB700SC while riding home from work, splitting lanes in heavy traffic on the freeway, over 20 years ago. No problem shifting up and down with a completely limp clutch lever. Fortunately for me the traffic cleared up and the fluid cooled off before I got off the freeway. But when I parked it at home and touched the slave cylinder, I burned the **** out of my finger.
I've driven cars with a broken clutch cable, and with a blown slave cylinder, by turning the starter over in 2nd gear to get it running...then no problem.
I had the fluid boil in my '86 CB700SC while riding home from work, splitting lanes in heavy traffic on the freeway, over 20 years ago. No problem shifting up and down with a completely limp clutch lever. Fortunately for me the traffic cleared up and the fluid cooled off before I got off the freeway. But when I parked it at home and touched the slave cylinder, I burned the **** out of my finger.
Don't know what else to say about it.
Thread Starter
Member
Squid
Joined: May 2011
Posts: 74
I'm glad to see all of these late nighters on here! Thanks everyone for your input on EVERYTHING and if anything changes on the clutch situation I will be sure to update everyone. I have been reading about r/r issues on the forums... is this something I should be concerned about? Any suggestions?
Thread Starter
Member
Squid
Joined: May 2011
Posts: 74
--Update Bump--
It was the slave cylinder not operating properly. I ripped it apart rebuilt it and it's working flawlessly. I used 1500 grit wet/dry sandpaper on the inside of the housing because it was a little jacked up. I then followed up with some 2000 grit. The piston was sticking on the walls of the slave housing which caused it to bind and not work properly. I replaced all of the internal parts include the piston cost me about 50$ for everything. I did however replace the clutch pipe, rebuilt the master cylinder and the last thing was rebuilding the slave. Kind of funny that it's always the last thing you check that is causing the issue. All in all it cost me 200$ for parts to redo the entire hydraulic system from top to bottom. Still cheaper than having the stealership even look at it and charge me for the one bad part. My biggest indicator of the slave not working properly was hooking up the bleeder(with no vacuum) and squeezing the clutch. Fluid would not leave the reservoir. I literally HAD to use the vacuum on the bleeder to get fluid to come through the line.
It was the slave cylinder not operating properly. I ripped it apart rebuilt it and it's working flawlessly. I used 1500 grit wet/dry sandpaper on the inside of the housing because it was a little jacked up. I then followed up with some 2000 grit. The piston was sticking on the walls of the slave housing which caused it to bind and not work properly. I replaced all of the internal parts include the piston cost me about 50$ for everything. I did however replace the clutch pipe, rebuilt the master cylinder and the last thing was rebuilding the slave. Kind of funny that it's always the last thing you check that is causing the issue. All in all it cost me 200$ for parts to redo the entire hydraulic system from top to bottom. Still cheaper than having the stealership even look at it and charge me for the one bad part. My biggest indicator of the slave not working properly was hooking up the bleeder(with no vacuum) and squeezing the clutch. Fluid would not leave the reservoir. I literally HAD to use the vacuum on the bleeder to get fluid to come through the line.
Senior Member
Superstock
Joined: Aug 2009
Posts: 380
From: Warrenton Virginia
The first summer I had my bike the clutch would disengage a few minutes into a ride, turned out to be a combination of dirty fluid and yes believe it or not air in the lines. the dirty fluid kept the pressure from returning to the reservoir and the air does what brake fluid doesn't, expand.
Thread
Thread Starter
Forum
Replies
Last Post
IronSpadeCycles
General Discussion
1
Oct 24, 2013 08:07 AM
little squirt
General Discussion
2
Apr 8, 2009 03:52 PM
