I've posted in more detail the story of my bike on my-mc.com, but I thought I'd see if anyone here can add to the excellent help I've received so far from them.
I've done a bunch of fettling on an ex-police bike I bought about a month ago after it had been in storage for about a year, and currently the issue I'm working on is the clutch.
Firstly the thermostat appears to be stuck open. I'll fix this in due course, but I mention it because I think it's relevant to the clutch issue, which appears to be heat related.
I flushed the clutch hydraulic fluid a week ago because it was getting pretty dark in colour and it seemed like a fairly sensible bit of maintenance. This is the first time I've bled clutch hydraulic fluid, so I could quite possibly have done a bad job of it. I also have recently flushed / replaced the coolant.
The clutch appears to work normally when the engine is cool (under about 1/4 on the temperature dial) but as the engine warms up, the clutch lever needs to be pulled further back before it appears to be actually doing anything to the clutch, the first part of the lever's movement seems to be only against the spring of the lever, and not the somewhat stronger springs in the clutch. I'm not getting any slipping, just more movement before the clutch disengages.
When I first noticed this odd behaviour, I suspected I'd made a hash of bleeding the clutch fluid, leaving moisture in there which was boiling at high engine temperatures and of course compromising the hydraulics. I had another go at bleeding the clutch and also had a good look at the reservoir and breather hole etc. Everything looked just perfect, the fluid was coming out the bleeder screw the same colour as it had gone in the reservoir, there was no obvious dirt impeding the master cylinder (I only looked through the breather hole in the reservoir) but after a squeeze / bleed / release cycle, the lever was taking several pumps before it felt like the I was fully connected to the clutch at the slave cylinder. Just as when the engine's hot, the first part of the lever's travel felt like it was against only the lever's springs, but as I pumped it half a dozen times or so, the travel before it felt like I was actually operating the clutch reduced to normal.
Is this normal? I was expecting it to only take one (or maybe two) pumps to fully fill the master cylinder and bring the clutch to normal operation. I didn't notice the first time I bled the fluid because I got my wife to man the lever, I'll ask her tonight if it did the same first time around.
Having re-flushed the clutch hydraulic fluid and put the bike back together, I took it for a test-drive and all seemed well until I noticed that the temperature dial was at about 1/4 (with 1/2 being normal operating temperature - ambient is about 15'C and I was traveling mostly between 40 & 60 mph) which suggests the thermostat is stuck open.
Once I got into town with speeds around 15-30mph, the engine temperature [edit: not "speed"!] rose and the clutch started acting up again, exactly as before. Having discovered that pumping the lever seemed to fix the symptoms with a cold engine, I thought it might help with a warm engine, but it didn't seem to make any difference. The only thing that seemed to help was speeding up for more air-flow over the radiator (oh NO! ;-)) but that's not much of an option in town traffic!
So, I'm thinking there surely must be moisture involved, reacting to engine heat, but I've bled the hydraulics twice and I'm pretty sure I got it right the second time around! Is there some secret pocket where wet fluid could get caught? What about the pumping-the-lever fix when I was flushing / bleeding, does that point to some problem with the master cylinder? (I'd rather not have to pull it apart, but if that's the fix, I will!)
Come to my rescue, ST-O! :-D
Cheers & God bless
Sam "SammyTheSnake" Penny
I've done a bunch of fettling on an ex-police bike I bought about a month ago after it had been in storage for about a year, and currently the issue I'm working on is the clutch.
Firstly the thermostat appears to be stuck open. I'll fix this in due course, but I mention it because I think it's relevant to the clutch issue, which appears to be heat related.
I flushed the clutch hydraulic fluid a week ago because it was getting pretty dark in colour and it seemed like a fairly sensible bit of maintenance. This is the first time I've bled clutch hydraulic fluid, so I could quite possibly have done a bad job of it. I also have recently flushed / replaced the coolant.
The clutch appears to work normally when the engine is cool (under about 1/4 on the temperature dial) but as the engine warms up, the clutch lever needs to be pulled further back before it appears to be actually doing anything to the clutch, the first part of the lever's movement seems to be only against the spring of the lever, and not the somewhat stronger springs in the clutch. I'm not getting any slipping, just more movement before the clutch disengages.
When I first noticed this odd behaviour, I suspected I'd made a hash of bleeding the clutch fluid, leaving moisture in there which was boiling at high engine temperatures and of course compromising the hydraulics. I had another go at bleeding the clutch and also had a good look at the reservoir and breather hole etc. Everything looked just perfect, the fluid was coming out the bleeder screw the same colour as it had gone in the reservoir, there was no obvious dirt impeding the master cylinder (I only looked through the breather hole in the reservoir) but after a squeeze / bleed / release cycle, the lever was taking several pumps before it felt like the I was fully connected to the clutch at the slave cylinder. Just as when the engine's hot, the first part of the lever's travel felt like it was against only the lever's springs, but as I pumped it half a dozen times or so, the travel before it felt like I was actually operating the clutch reduced to normal.
Is this normal? I was expecting it to only take one (or maybe two) pumps to fully fill the master cylinder and bring the clutch to normal operation. I didn't notice the first time I bled the fluid because I got my wife to man the lever, I'll ask her tonight if it did the same first time around.
Having re-flushed the clutch hydraulic fluid and put the bike back together, I took it for a test-drive and all seemed well until I noticed that the temperature dial was at about 1/4 (with 1/2 being normal operating temperature - ambient is about 15'C and I was traveling mostly between 40 & 60 mph) which suggests the thermostat is stuck open.
Once I got into town with speeds around 15-30mph, the engine temperature [edit: not "speed"!] rose and the clutch started acting up again, exactly as before. Having discovered that pumping the lever seemed to fix the symptoms with a cold engine, I thought it might help with a warm engine, but it didn't seem to make any difference. The only thing that seemed to help was speeding up for more air-flow over the radiator (oh NO! ;-)) but that's not much of an option in town traffic!
So, I'm thinking there surely must be moisture involved, reacting to engine heat, but I've bled the hydraulics twice and I'm pretty sure I got it right the second time around! Is there some secret pocket where wet fluid could get caught? What about the pumping-the-lever fix when I was flushing / bleeding, does that point to some problem with the master cylinder? (I'd rather not have to pull it apart, but if that's the fix, I will!)
Come to my rescue, ST-O! :-D
Cheers & God bless
Sam "SammyTheSnake" Penny
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