Stalling when shifting from neutral to 1st

[DucDen]

Hi all... this is my first post.  Im a new Duc M900 (1995) owner. Im also a new rider will limited bike riding and tech experience.  I have been riding my bike around my neighborhood while I wait for my MSF class Aug 2nd.  I have one issue that is driving me nuts and Im not sure what the fix is.  I start the bike and allow for it to warm up. When I shift from neutral to 1st with the clutch engaged the bike stalls and jumps forward ever so slightly.  I can get around this issue if I rev the throttle slightly.  As a new rider this is not the easiest thing cause the bike jerks slightly and its a scary way to take off.  I have ride an old 1981 suzuki GS850 and that bike  allowed me to engage the clutch drop the bike into first and slowly let out the clutch without revving the throttle.  This is what Im assuming all bikes should  do.  Also if I attempt to start the bike in 1st gear with the clutch and front brake engaged the bike also jumps forward.  Im guessing this issue relates to the other issue.

Does anyone know what might cause this issue?  Any suggestions on how to fix it would be great.

Thanks,

John
Denver, CO, USA

[Howie]

When you say engage the clutch I assume you mean pull the lever to the grip so you can shift into first?  In that case, you are disengaging or releasing the clutch.  Engaged, engine connected to transmission.  Disengaged, engine disconnected from gearbox.

Your symptom is clutch drag, the clutch only partially disengaging.  Do the cheap thing first, bleed the clutch.

[DucDen]

Sorry about the confusion.  Yes I mean Im pulling or squeezing the clutch lever in toward the handlebar and once I attempt to put the bike into 1st (w/ the lever still fully squeezed), it stalls and jumps the bike forward ever so slightly.

[Hedgehog]

Ducatis use a hydraulic clutch, and the clutch slave cylinders on your bike ('90s vintage) were especially prone to leakage and taking on air.  If you look around for instructions on "bleeding a ducati clutch" or similar verbiage, you will find loads of websites taking about the problem.  What it boils down to in the end is that there is air in the hydraulic line, and when you squeeze the lever, a lot of the lever movement is used up compressing the air, rather than engaging the clutch.  There are other possibilities, of course, such as maybe your master cylinder is empty, but it almost always boils down to the slave cylinder.  Many people simply switched to an aftermarket slave to get out of the problem, altogether.

[stopintime]

The good news is that it will be OK - not even old Ducatis are supposed to be like that.
If you are "lucky" it is the slave cylinder, new aftermarket slave will also provide a lighter pull on the lever.
I've heard good things about the Evoluzione slave, but I have a wet clutch AND therefore not really a clue
Good luck with your bike and welcome on the DMF

[DucDen]

Okay I have done a search on what this process in-tells and Im off to get a hose and some new brake fuild to bleed/change the clutch fluid. I just ran down and pulled the lid off the slave and there is almost no fluid in the chamber.  The old brake fluid looks cloudy and dirty.  I will post the results once I get back and have the job complete. 

For anyone having similar issue that want to do this job themselves... I found this link and this is the process Im going to follow.

http://www.motorcyclistonline.com/howto/122_0306_hydraulic_clutch_service/index.html


Thanks everyone... I will post an update once Im done.

John

[Ddan]

The dirty fluid is typical of Ducati clutches.  More importantly is that the fluid was so low.  Check the slave cylinder for an accumulation of crud around it.  If it is leaking badly enough that could cause your problem.

Another thing to check is if you have adjustable levers.  If there is a dial near the pivot of the lever, you do.  Extend the lever away from the bar a bit and turn the dial, you may just need a bit more throw to fully disengage the clutch.

[DucDen]

Okay,  1 task down 7999 more to go!   As for now this appears to have corrected my issue.  I didn't have time to ride the bike and give it a full field test but the initial test was 100% better. 

One final question:  Is filling the slave up a high as possible the correct thing to do or not?  I have it about 3/4 full.   I took a look at the front brake slave and its closer to about 7/8 full.  I haven't bleed the front brake line yet but that is next on my agenda.  I don't want to over fill them if Im not supposed to, because Im not sure if they work like a power steering pump works on a car.  Basically Im not sure if it needs any air in the chamber to work properly.

Things to note for newbie like me.  The tension or the amount of force it takes to pull back on the clutch lever is 100% harder.  My brake lever is still harder to pull back but there was a 100% improvement from before.  Also when bleeding the line I was expecting to get the fluid to look like it did straight out of the bottle (a watery golden/oil color).  This was not the case.  Even with after 15 min of pumping new fluid into the chamber it was bleeding out a hazy (watery) gray color.  There was a noticeable difference between that and the original milky grayish/black fluid that originally came out of the line.  Also for newbie's or rookie mechanics that arent sure if they want to take this sort of an issue on, this project was as hard as making cerial. If you can make Americas favorite breakfast you can bleed your clutch line. 

Tools:
8mm wrench ($5-9 at Sears, I couldnt find my 8mm wrench so I bought one for $5.99)
1/4" (6.35mm) Inside diameter tubing (the outside diameter doesn't matter but I picked up 3/8" OD x 1/4" ID x 10' Length, clear tubing at Home Depot for $2.49)
Dot 3, 4, or 5 Brake Fluid ($? I already had some but its only $3-5 for a quart of it)

I want to thank everyone who made suggestions!

[Ddan]

Good that you got it sorted.  Now just watch the fluid level and if is dropping, your probably going to need a new slave.  The level in the master (on the handlebar) should be just a bit below full.  As the fluid heats, it expands, so you need some room.   

[teddy037.2]

One final question:  Is filling the slave up a high as possible the correct thing to do or not?  I have it about 3/4 full.   I took a look at the front brake slave and its closer to about 7/8 full.  I haven't bleed the front brake line yet but that is next on my agenda.  I don't want to over fill them if Im not supposed to, because Im not sure if they work like a power steering pump works on a car.  Basically Im not sure if it needs any air in the chamber to work properly.

you mean the reservoirs on the master cylinders? because the brakes don't have a slave 

there should be high and low fill lines, sorta like the sight glass on the coffins style masters.

[printman]

Even with after 15 min of pumping new fluid into the chamber it was bleeding out a hazy (watery) gray color.  There was a noticeable difference between that and the original milky grayish/black fluid that originally came out of the line.

That is normal and doubt it could be completely removed. Sounds like it's sorting its way out. I would clean around the slave cylinder (bottom) to see if new fluid is leaking. They have been known to leak, mine did.