Differences between Gen 2 and Gen 1 & 2.5 Clutch Assemblies

[JamesK]

Fred, thanks for the follow up. I am confused as to how the Push Rod could be the smoking gun (looked at this difference before) since the Push Rod P/N for the 2006 & 2009 Gen 2 is the same, but the clutch slave cylinder is different. It thus must be some other components making the difference.

 

[ahchiu]

The difference is the diameter of the piston in the clutch slave, 05 is larger than the 06,07 I changed out and as other have said the engagement point is sooner on stock levers, I changed to Pazzo's with more adjustment and was able to adjust in the right engagement point.

 

[Fred W]

The difference is the diameter of the piston in the clutch slave, 05 is larger than the 06,07 I changed out and as other have said the engagement point is sooner on stock levers, I changed to Pazzo's with more adjustment and was able to adjust in the right engagement point.

Yes, yes... I think everyone understands this.

The question is, why is the engagement point shifted towards the bars on the 2006 and 2007's when using the 1st gen slave when it isn't that way on the 1st gens or later 2nd gens with the 1st gen slaves? They all use the same identical master cylinders and levers, so when you put the 1st gen slave it it should behave like a 1st gen, but doesn't.

 

[Fred W]

Fred, I'm following this thread to find some resolution to this issue on my own bike.
System is self adjusting, piston in slave doesn't retract more than rod pushes it back,

therefore, length of rod shouldn't make a difference.

Piston will always "null" at rest, no take-up is necessary.

Yes, that should be true.

Fred, thanks for the follow up. I am confused as to how the Push Rod could be the smoking gun (looked at this difference before) since the Push Rod P/N for the 2006 & 2009 Gen 2 is the same, but the clutch slave cylinder is different. It thus must be some other components making the difference.

I agree it doesn't make sense that this would be the cause. But we know that something that is different between the 1st and 2nd gen has to be causing this phenomenon.

There are some other parts that may or may not be involved: Part #4 the Plate Seat and #5 Spring Clutch Boss are parts that are uniquely different part numbers for just the two model years with the problem. I don't see how they could cause the problem, but it could be significant that when Yamaha went back to the 1st gen slave they also went back to using these 1st gen part numbers.

 

[richsp51]

Just to add another pair of eyes to the issue...

It seems that going back to the original post by JamesK ,comparing the 2007 and 2009 parts lists and observing the differences, is a good approach. It's just that James missed a couple of parts that Fred has pointed out, plus the addition of item #3.

I did a comparison too and here's the differences list that I identified: (note the bold ). Ref: partzilla.com , same as original post.

2007 2009
----------------------- -----------------------
3 3P6-16371-00-00 3 3P6-16371-20-00
BOSS, CLUTCH BOSS, CLUTCH
$95.49 $63.45 1 $93.95 $62.28 1

4 3P6-16384-00-00 4 36Y-16384-00-00
PLATE, SEAT PLATE, SEAT
$13.49 $9.20 1 $12.49 $9.29 1

5 3P6-16383-00-00 5 36Y-16383-00-00
SPRING, CLUTCH BOSS SPRING, CLUTCH BOSS
$27.95 $18.29 1 $36.49 $27.21 1

8 2H7-16385-00-00
RING, CLUTCH BOSS
$10.95 $8.16 1

14 95812-06025-00 15 95817-06025-00
BOLT, FLANGE BOLT, FLANGE
$1.28 $0.88 6 $1.49 $1.01 6


28 2D2-16381-00-00 29 5JW-16381-00-00 <- Slave cylinder
PUSH LEVER COMP. PUSH LEVER COMP.
$134.49 $87.41 1 $136.99 $89.02 1


Manufactures don't like to needlessly create new part numbers as there's a significant cost to doing this, so.... there must be dimensional changes that stack up to make a difference in clutch engagement/disengagement points between the GEN II and GEN II.5 models.

 

[ahchiu]

 

[Fred W]

The #3 clutch boss changed twice (it's different on each of the three subsets). The parts that seem really suspicious are the #4 and #5 which changed from 2005 to 2006, then changed back to the 1st gen part number in the later 2nd gens.

 

[RaYzerman19]

OK, I'll throw in my monkey wrench............ First, my observation on my Gen II was that the lever was not as far away when clutch disengaged, but it had to hit the handlebar or almost, to disengage the clutch. Changing to a Gen I slave meant adjusting the lever to be further away from the handlebar to get the same disengagement point at the handlebar. Longer fingers required, in other words. But, remember, nothing changed on my bike as far as the clutch basket stack or the push rod, on a then relatively new clutch. I got the Pazzo levers which helped the reach a bit.

Design-wise, the master cylinders are all the same for all years, it just took more fluid to stroke the larger Gen I slave... we all understand that. The amount of pushrod travel with all things equal would be the same amount to disengage the clutch. Mama Yama would have designed the amount of protruding rod into the slave cavity so there was extra rod to compensate for clutch wear. How much, we don't know, how much wear does it take for the slave to bottom out and not completely disengage the clutch we don't know. It should be 3 mm or more...... keep reading.

However, the big players in reducing that rod length are the friction plates as they will be the fastest wearing parts in this whole deal. If we assume a new plate is 3.10 mm and one at the wear limit is 2.80, then in the 7 plate stack we've lost 2.1 mm. of effective rod length/room for the slave to bottom out. That doesn't count any wear in the two thicker friction plates or any of the metal plates, nor any of the pressure plates. If we add a bit for the two large friction plates, let's make it 2.5 mm. (It's really more complicated than that, as not all these will wear at the same rate or amount).

What is a constant is the larger spring #12 or #13 depending on which diagram you're looking at, is compressed significantly as it is bolted on by 'pressure plate 2'. It's more than enough force to keep this stack tight so you aren't likely to get clutch slippage (unless you got the wrong oil or the friction plates are severely worn). You've got to screw those bolts in a long way to seat pressure plate 2 and it's a lot more than 2.1 mm.

In my opinion, any changes to the parts for various years in the clutch basket and the rod, etc. won't be enough to lose the required amount of protruding pushrod into the slave cavity. It's an opinion, until that's proven, but one still has to think the effective rod length at the slave cylinder has a very similar if not identical amount of margin.

James' high miler has likely worn friction plates, therefore he noticed when installing the Gen I slave he couldn't get enough stroke to completely disengage the clutch. I suspect he's run out of effective rod length to do so. Or, if by chance there is more rod/slave travel available, he has got to put the lever in the next position forward, which is likely not ergonomically comfy at all. Certainly beyond my reach to operate the bike safely.

Anyway, that's my spin...................

 

[Fred W]

Ray, I think maybe you've got it a bit backwards. As the clutch pack wears, and the plates become thinner, the pressure plate will move further inboard when released, and push the clutch rod to protrude further into the slave cylinder on the opposite side of the engine, under the clutch spring's tension.

I suppose that it might be possible that, with enough wear, eventually the protruding rod would cause the slave's piston to bottom out in its bore when releasing the clutch, but if/when that happened it would hold the clutch slightly disengaged and cause it to slip. That isn't what we are dealing with here.

Whether the plates are worn or not it should require the exact same stroke from the slave through the rod to push the pressure plateback the same distance and release those worn plates

 

[RaYzerman19]

Naw, I was just testing ya.......... you're right, I am 180 out. And it's true, it will take the same amount of stroke, worn or not. Just re-read post #1 again..... if I understand it right this time, all James is trying to do is change the engagement point such that the stroke with a Gen 1 slave is the same on a Gen II as it is on the Gen I. Well, it is, isn't it? The disengagement point means a lever position of almost or at the handlebar, the starting point is further forward on a Gen I. I'm having difficulty understanding how one would even change that without a larger bore master (which will just raise the effort again). It doesn't matter what the stack of clutch components are, if worn, the rod just gets longer. If design among different years has a different effective rod length, don't matter. So, to me, it seems the Gen I slave on a Gen I strokes longer than a Gen II slave on a Gen II, simply because of the larger bore. Moving the Gen I slave to a Gen II just makes it the exact same as a Gen I bike....... in other words, all you Gen I guys have a longer stroke the whole time....... (and as the old joke goes, the reason the knob is on the end is so you don't whack yourself in the forehead...). There would seem to be no cure for James' issue, unless I'm really missing something.

 

[Fred W]

You know, you make a great point in there. I have never actually ridden a 2nd gen w/ 1st gen slave before, so maybe it is exactly the same as the way a 1st gen works? I can say that I've never felt like the engagement / disengagement point was particularly close to the bars, but maybe in comparison to the 2nd gen with 2nd gen slave it is closer?

We need some actual data!!

 

[richsp51]

Looking back at some of the older post on this subject, back in 2010 the notion of a spacer in the slave cylinder cup was discussed by some of the same folks in this thread. See:

https://www.fjrforum.com/forum//index.php/topic/126113-changing-clutch-engagement-point-without-adjusting-the-lever/page-2

Seems like inconclusive results but maybe someone has updates or new thoughts about this?

 

[RaYzerman19]

Let's define some things so we're all talking apples and apples............ the engagement/disengagement point of the clutch lever vs. handlebar is adjustable via the lever adjuster. The Gen I slave causes the lever travel difference between engagement and disengagement to be larger due to it's larger volume of fluid required to move the slave.

My definition (or preference) is that when cold, I want my clutch to be disengaged just before the lever hits the handlebar. If we use that as the benchmark/starting point, if I remember right, my Gen II slave-equipped bike would have the lever adjusted at position 3, and with Gen I slave the lever is adjusted at 4 (might have been 4 and 5 respectively, it's been a while). This also means, besides having to reach further with the Gen I slave, the full engagement point of the clutch is further away from the bar but before the lever is fully released. Confused yet? The Pazzo levers have 6 positions, and with the Gen I slave I have it set at 4. If I set it at 3 (my real preference), I get a slight clutch drag when pulled right to the bar, especially when cold, i.e., difficult to find neutral. At 4 no problem. When the engine is warmed up/hot, I can get away with 3 but it's still marginal.... should also note, this is with grip puppies or grip buddies. If you don't use these, then you may get away with lever settings one notch closer than mine.

It would be good to know where the Gen I and Gen II guys have their levers adjusted to, with original slaves. Chances are the Gen II folks have theirs adjusted one notch closer than the Gen I folks.

About that AE, the '09 A used the Gen I slave, the '09 AE uses the Gen II slave..... might have something there.

To me there is no logical reason adding a spacer in the slave will change the amount of travel. Therefore, I'm not seeing where the disengagement/engagement points would change on the lever, it still has to travel the same amount no matter what.

 

[JamesK]

Just to add to Ray's request for the stock Gen II lever settings, pls also state your glove size, as this would be a factor in what setting is ideal for you.

I take size L in most gloves (but am at the lower end of the L size).

I have the Pazzos set at 5 now (need to double check when I get home tonight) but would prefer 4. I don't believe I could ever really get away with the 3 setting, but I did change to the Gen I slave at well over 100k miles so if there's any logic in some factors relating to clutch part wear than that would possibly explain it.

 

[Constant Mesh]

Whatever it takes to get a 2.9 mm stroke of the clutch pressure plate.

For the 29.6 mm D slave piston, master cylinder piston stroke >= 13.0 mm

For the 33.6 mm D slave piston, master cylinder piston stroke >= 16.7 mm

 

[Fred W]

I would say that the goal is to have the engagement/disenagement point far enough away from the handlebars so as to be complete. Further away from the bar isn't really a problem. The problem with the Gen 2 2006's & 2007's is that in order to adjust the lever to produce enough stroke to achieve this goal you end up setting the resting position of the lever too far away from the handlebars for the ergonomic preference of many riders.

PS - Constant Mesh, curious where you got those stroke numbers.

 

[Constant Mesh]

In the 2006 Service Manual the pressure plate stroke is specified for the AE model. The required minimum stroke for satisfactory clutch operation is listed as 2.8 mm or greater.

I'm assuming the clutch and its components are the same for the A and AE models. They have different slave cylinders but I believe the piston diameter is the same for both, no differences are mentioned. However, the hose connection is different.

I calculated the required master cylinder piston strokes for a 2.9 mm pressure plate stroke.

 

[RaYzerman19]

Fred, have I got it backwards again? I thought the Gen 1 resting position would be further forward being that it needs more stroke to accomplish the same goal.

 

[richsp51]

I haven't done the GEN I clutch slave swap on my GEN II YET .... getting close to doing it , but from many of the posts that I've read my interpretation of the complaint/concern from those that have done it, is what Fred stated, namely....

The problem with the Gen 2 2006's & 2007's is that in order to adjust the lever to produce enough stroke to achieve this goal you end up setting the resting position of the lever too far away from the handlebars for the ergonomic preference of many riders.

If you compensate by moving the resting position of the lever closer for ergonomic purposes, the disengage doesn't happen before the lever hits the handlebar.

Have I interpreted this correctly?

I would add that this also applies to 2008 as the "problem" was resolved in 2009.

 

[richsp51]

In the 2006 Service Manual the pressure plate stroke is specified for the AE model. The required minimum stroke for satisfactory clutch operation is listed as 2.8 mm or greater.
I'm assuming the clutch and its components are the same for the A and AE models. They have different slave cylinders but I believe the piston diameter is the same for both, no differences are mentioned. However, the hose connection is different.

I calculated the required master cylinder piston strokes for a 2.9 mm pressure plate stroke.

I wonder what the 2009 Service Manual states the minimum stroke for satisfactory clutch operation.

Maybe the 2009 somehow requires a slightly shorter stroke then the 2006->2008 model years? Going back to those part differences between the 2007 and 2009 comparisons, maybe those parts are responsible?