'13 A&S Clutch retrofit?

Yamaha FJR Motorcycle Forum

Help Support Yamaha FJR Motorcycle Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

DeSudet

Well-known member
Joined
Apr 24, 2015
Messages
155
Reaction score
40
Location
Phoenix
Obviously, I'm no expert, but comparing the 2016 parts diagram to the 2013 parts diagram, it seems to me that swapping out the clutch boss, a couple of bearings, the pressure plate, and clutch plates would convert any of the Gen III bikes to the new slipper clutch from the '16. Adding those parts to my cart gives me a total of under $300 before shipping. Any chance those of you who are infinitely handier with a wrench than I could check my work?

 
As a non-expert as well, I can't wait for the "infinitely handier" to chime in on this one!!! If only the parts that you cite is all it takes to convert, I will be on it in a New York minute!!

 
I see at as everything from #3 to #13, in the quantities indicated, plus 17 and 22. (22 is a splined plate that you bend over the nut to lock it, and even though it's the same part in each year, it should not be reused.)

14, 15, and 16 are the same as the comparable 2013 parts, but you should get them so the assemblies would be complete, allowing you to sell the old clutch should you want to, or swap it back in.

I need someone to explain why there are 3 kinds of #17, and how do you choose? Are they different thicknesses, giving a different bite point? Maybe adjusts the thickness of the stack? Purely guesswork on my part.

 
Last edited by a moderator:
Interesting for sure, but would seem to be too easy...... slipper clutch assemblies usually cost more like north of $1200 (racing versions?)........ what makes this one so easy. The pressure plate end of things would seem to be key. I can't speak knowledgeably about slippers........ will have to study up.

 
I see at as everything from #3 to #13, in the quantities indicated, plus 17 and 22. (22 is a splined plate that you bend over the nut to lock it, and even though it's the same part in each year, it should not be reused.)
14, 15, and 16 are the same as the comparable 2013 parts, but you should get them so the assemblies would be complete, allowing you to sell the old clutch should you want to, or swap it back in.

I need someone to explain why there are 3 kinds of #17, and how do you choose? Are they different thicknesses, giving a different bite point? Maybe adjusts the thickness of the stack? Purely guesswork on my part.
Don't forget the spacer #21. Other than the locking tab #22(Didn't even cross my mind that it should be replaced), I came up with the same parts.

Interesting for sure, but would seem to be too easy...... slipper clutch assemblies usually cost more like north of $1200 (racing versions?)........ what makes this one so easy. The pressure plate end of things would seem to be key. I can't speak knowledgeably about slippers........ will have to study up.
I'm not sure why it seems so comparatively cheap. The only thing I can figure is that for professional racing setups, you'd need something a lot beefier than I imagine many makers use stock. There may also be rather significant differences in design. Looks like the pressure plate and clutch boss are the key. Looking at the parts diagram compared to the video below, specifically made for the Star cruisers, it looks like it uses the same design. Learn sumthin!
biggrin.png




I'm sure it's not nearly as easy as it appears, largely due to the #21 spacer being behind the basket, meaning the whole assembly needs to come out, but at least it should all be accessible from the one side. I might go ahead and do this anyway, assuming I can convince the dealer to order all these parts for the wrong bike. They looked extremely skeptical when I gave them a part number for a '14 ECU.

Them: "This is for a '14 or '15, right?"

Me: "Sure!"

Them: <pointed stare while they obviously debated the wisdom, and possible liability, in explicitly asking for confirmation>

Me: <Wink!>

Them: <shakes head and sighs, plausible deniability intact>

 
I skipped the spacer because it's outside of the clutch boss, behind it, and not part of the assembled boss and the plates it contains.

The nut on the clutch boss is 30mm, and you'll probably need an air impact socket to remove it. When replacing, it torques down to 90 newton-meters, or about 65 lb-ft for us 'Muricans. Thing is, without clutch engagement there's nothing to hold the boss in place while you tighten it. The service manual describes a tool that grabs the outside of the boss to hold it. What I did in my transmission repair was have someone hold the rear brake while I tightened it against the drivetrain. That moves a lot more than you'd expect, because the middle gear shaft transfers drive to the bevel gear through a cam device which is held by a heavy spring. You WILL move that cam device while tightening the nut, so don't think you're breaking something in the drivetrain when the boss turns a little with the wrench before it actually tightens down the nut.

So there's still no one going to teach us what the differences in the #17 UR plates are; what the T1.6, T2.0, and T2.6 mean?

 
Last edited by a moderator:
I did a little research, not sure I'm much ahead....... the #17 thing is (to me) implying there is a shimming to be done if a certain stack-up is evident....... perhaps we should wait until the 2016 FSM is available which might explain more specifically how this particular version of a slipper works.

 
Why?? The only reason to need a slipper clutch is if you don't know how to modulate the lever on the left. Time and money I don't see a reason to spend, but have fun.

 
I did a little research, not sure I'm much ahead....... the #17 thing is (to me) implying there is a shimming to be done if a certain stack-up is evident....... perhaps we should wait until the 2016 FSM is available which might explain more specifically how this particular version of a slipper works.
That was my take too, thickness variations. I wonder if it would have an effect on the clutch pull? A thinner one putting less pressure on the springs?

Why?? The only reason to need a slipper clutch is if you don't know how to modulate the lever on the left. Time and money I don't see a reason to spend, but have fun.
I have no problem with working the clutch on up and down shifting, and if anything, tend to under-rev the engine. Not quite lugging it, but hardly worried about locking up the rear and needing to have the slipper bail me out.

I'm more interested in the supposed 20% reduction in clutch pull. At the same time, it would add a perceived value if/when I get around to selling it.

 
I'm more interested in the supposed 20% reduction in clutch pull. At the same time, it would add a perceived value if/when I get around to selling it.
Aahhhhhh...I forgot about the reduced pull claim. That would be interesting if it's actually true. Never thought about perceived resale value...

 
The lesser clutch pull would be affected more by the outer pressure plate with the three springs vs. the "big washer shaped" spring of the original clutch.... First, we should measure clutch pull on a '16 vs. other GenIII's which also claimed less effort clutch pull.

 
I just realized my "why" post sounded more ******* than I meant. Sorry!!
No worries. We're used to it from you! :p

The lesser clutch pull would be affected more by the outer pressure plate with the three springs vs. the "big washer shaped" spring of the original clutch.... First, we should measure clutch pull on a '16 vs. other GenIII's which also claimed less effort clutch pull.
It's called a diaphragm spring ;) And you're absolutely right. For half the price, I could just convert over to a coil spring pressure plate from Barnett, but I also like the idea of a slipper, even if I never really use it. In fact, I'll openly admit to going for the 'cool' factor of being able to brag about having one. Pirates, squids, and the Gixxer tools will be impressed (Isn't that what we all live to do? Ha!) and I won't have spent $1200 to get it. :D

 
I would worry that reduced pull effort from simply having a lighter spring would also mean reduced clamping by the pressure plate and eventual clutch slippage and runination. In other words, don't just change out the pressure plate spring without changing out everything that was made to go with it.

 
I would worry that reduced pull effort from simply having a lighter spring would also mean reduced clamping by the pressure plate and eventual clutch slippage and runination. In other words, don't just change out the pressure plate spring without changing out everything that was made to go with it.
I'm pretty sure that's where the Assist part of the A&S clutch comes in. The slipper part we've covered: When the wheel is turning faster than the engine, it forces the pressure plate away just enough to allow the discs to slip. The flip side of that should cause the pressure plate to clamp down harder on the discs when the engine turns harder than the wheels. When you've leveled off the throttle, you don't need a whole lot of compression on the discs to maintain and the clutch boss would return to a neutral state, neither clamping down on or slipping the discs. Please correct me if I'm wrong, and cite good arguments. Some may recall that I don't just admit to being wrong because someone says "You're wrong!" :D

 
I don't think there would be a tightening mechanism, just the release for overrun. In other words, whatever it is that makes it a slipper clutch pushes the pressure plate out when the output side is faster than the input side, but there's no requirement that it actually pulls the pressure plate back in. That's what the pressure plate spring is for. All it has the the spring. No increased clamping just because power is applied.

 
I don't think there would be a tightening mechanism, just the release for overrun. In other words, whatever it is that makes it a slipper clutch pushes the pressure plate out when the output side is faster than the input side, but there's no requirement that it actually pulls the pressure plate back in. That's what the pressure plate spring is for. All it has the the spring. No increased clamping just because power is applied.
Not sure how I missed this one. The video Yamaha put out for the A&S clutch on their star line (same clutch boss, pressure plate, and springs as the '16) specifically says that power from the engine causes the pressure plate to clamp down on it. Link

 
Top