86 VF500F Clutch has small friction zone

I guess the real question should be where do you want to engage at 1/4 1/2 3/4?

 

I'd like it to start engaging at about 1/4 to 1/2 way out from the bar. Right now it doesn't start to grab at all until about 7/8 of the way out from the bar.

I'll check out the return line on the master cylinder too.

Thanks for the help everyone. I'm really loving the bike.

 

There great bikes ive had mine for nearly five years which its now going under a full resto but nothing out there can compare to these lil miniceptors.

 

Try cleaning that hole it might help? Im think there's not much that can be done about it though?

 

You'll get the most air out of the system by removing the slave from sprocket cover and using a C-clamp to hold it fully retracted while bleeding.

 

Thanks squirrel. Should I just rebuild the slave cylinder while I have it off?

 

It's not air

If you had air in the lines then you would be pulling the lever all the way to the bar and still have little or no action (disengagement) of the clutch and/or brakes, whichever the case may be. The fact that you DO have clutch action indicates an air-free system.

On both the clutch and brakes, and throttle cables also, you would like to have a small amount of free play, ~ 2-3 mm is sufficient. The free play or slack ensures that the control levers, lines or cables are not applying a small amount of force on the actuators.

When you let off the brakes you want them free and clear of the wheels with no dragging. When you let out the clutch you want the full force of the pressure plate springs to engage the friction plates and put torque into the front sprocket. When you let off the throttle you want the engine power to drop immediately.

One other possibility besides crud in the master cylinder return port, is +25 year old rubber hose breaking down and shredding internally--it may look good on the outside but the inside wall will eventually shed debris that can collect to form a sort of one-way valve. The fluid will flow toward the actuator due to the high pressure of the master cylinder, but it will be very restricted in the back flow such that the pressure is never quite released on the actuator--causing clutch slipping or brake dragging, etc. It's more common in brake lines than clutches, but it can happen...

It never hurts to bleed your fluid lines, but it won't solve your problem in this case.

Once you get the return line clear, then the position of clutch lever engagement is basically determined by the fluid volume ratio of the master and slave cylinders--you would have to change one of the cylinder's diameter to move the lever, or get some adjustable levers to put it where you like it...

 

^ Well noted tech write up kennybobby. Thanks for the post.

 

Yes, thanks. I unfortunately have bigger problems with the bike now. It appears to have sprung a leak somewhere around the transmission that is dripping oil onto the exhaust collector. I looked down while at a stop light last night and saw smoke burning off the collector. This is over my head so I'm going to try to take it to a trusted bike mechanic today.

 

Sounds like the dreaded clutch push rod seal.

There are some simple and not so simple fixes to this. The caveat is that the simple fix is really only a temporary fix while the permanent fix involves splitting the cases.

To inspect, pull the clutch slave cylinder and take a look at the seal for the push rod. You should be able to tell if this is the culprit.

Good luck!

 

well, I had the slave off last night. what should I have been looking for? There did not seem to be a seal on the push rod...

 

Check here:

 

am I just looking for leaks there? if so, there weren't any

 

Okay, check this off the list and move to the countershaft seal next.

 

ok. that is directly behind the front sprocket, correct?

 

and BTW, thanks for you patience! It is greatly appreciated!

 

Yes, directly behind the drive sprocket. I am hoping this isn't the culprit as it can mean larger issues, i.e. bearing failure.

For some light reading about the heavy lifting required to replace these seals, check out ron.ciere.313's thread:

http://vfrworld.com/forums/mechanics-garage/34043-countershaft-seal-replacement-vf500f.html

 

hah! I've been reading that thread (and cringing) while waiting for you to reply. If it is that then I'm outta here. I can't do a full teardown.

 

4.5 months of hard, organized, and costly work. I'm really hoping it's not that countershaft seal and/or the bearing. If so, I'm afraid I'll have to sell it.

 

ok, so I found the leak...ugh.

BEFORE the cleanup...note the leak


AFTER the cleanp...still leaking


so, here's my game plan. I'm going to order the new seal for it. If it doesn't have a hard ridge on the inside then I'll get some picks and dig out the old one and shove the new one in. When I spin the shaft it sounds kinda gravelly...I'm not sure what it is supposed to sound like.

Anyhow, once the new seal is in, I plan on riding the bike. I bought it and enjoy it, but I don't want to put a ton of money into it. Heck, I may just keep riding it until the part gets here. All I need to do is keep an eye on the oil level.

Sorry that this thread has gone off track from the clutch thing.