Hello, I have an 86 vfr750 with about 15k miles on it. I recently rebuilt/replaced much of the clutch hydraulics and it had been working great until I noticed the 'biting point' for the clutch moving farther and farther from the grip. I have all new fluid, master and slave parts. I tried adjusting the freeplay, but it didn't seem to get me vary close. I would assume that the plates and springs are worn out, but the bike doesn't have much use on it, but then again I don't know how abused it was by previous owners. Is there anything else I can check before dropping the oil and buying clutch plates and springs? Thanks!
Check for a plugged up return orifice in the master reservoir. It is a very tiny pin hole that is easily clogged by spooge in the clutch/brake fluid or shreds of old rubber from the inner layer of old brake lines. The symptoms of a blocked hole are exactly those you have--the release/engagement point for the clutch lever moves way off the grips at the extreme range of motion. Eventually it will get so bad that the clutch will slip with the lever all the way out as the return pressure maintains thrust on the pressure plate stack. Sometimes the hole is covered by a shiny plate when you look down into the master. Another culprit with those symptoms is collapse of the inner lining of brake/clutch lines that flap into the flow path and form a one-way valve in the line--pressure flows toward the slave but can't return sufficient to release the clutch pressure plate or brake pads. Especially in 25 year old hoses...
Should I just scrape it out with a wire? Or should I drain the reservoir and blast it with air or carb cleaner?
Don't use carb cleaner on brake fluid parts, the types of rubbers used are not compatible. Easiest and quickest way to see if that's the problem is to rod it out with a wire. Maybe empty the master cylinder with a turkey baster then wipe out the bottom with rags to see if you have a layer of thick waxy sludge in the master and in the hole... With only 15k miles i doubt your clutch plates and pressure plates are worn out.
Thanks Kenny, that did the trick. Under that little metal piece there was some nasty stuff. However, I think I lost that little metal piece under my bench...its only purpose is to keep the passage free of blockage, right?
Yes it doesn't really do anything except keep fluid from shooting out the bowl when you pull the lever with the lid open...
yeh thoughtful honda wanted to protect ur peepers from spraying brake fluid! its like a little shroud thingie (have had the distinction of getting everything from carbie cleaner, oil, to petrol in my eye-balls, contact lenses were a good thing to have at the time, but no substitute for some saftey glasses) - I replaced my clutch line to a braided steel one, just some food for thought, but then again I do that to everything I have owned. That tiny little conikle looking hole under that funky honda sroud should bubble very faintly with a nice smooth stroke of your clutch lever, do it slowly so you dont get that crap in your peepers! You can take a piece of wire out of a brush and use some needle nose pliers to gently probe that hole, if its nasty you could take the end of a q-tip and cut off the end and clean that conicle looking hole, and between that and the wire reeming, you may luck out...keep us posted yah KNOW.
Keep in mind that a visual inspection is possible without having to drain the oil. I just recently changed my oil, then had to mess with the starter clutch and didn't want to drain it again... fortunately, around the same time I saw someone's post on here about how to get the right side cover off without draining the oil: 1.) Put a 2x4 under the rear wheel 2.) Bike up on side stand 3.) Remove side cover This will keep all the oil in and out of the way so you can easily service the clutch or starter clutch.
