Starter Clutch

Just checking to see is anyone has replaced a starter clutch assy on a Seca 750.
The motors are so damn dependable that I've never needed to R&R one. But the current motor in frame has a starter clutch that is showing serious signs that it will comlpletely fail in the near future. Does anyone know if this can be removed without pulling the motor and spliting the casehalves?
I've ran these motors for years but never needed to split the cases before.

 

I know there is a so-called -- "Short-cut" that will allow you to install a Starter Clutch "Kit" -- that works on the XJ900RK.

This process only allows you to renew the Springs and Rollers.

This Shortcut was first published by me, on another site, from notes of an interview with one of YAMAHA's most talented Professional Technicians.

My text ... along with refinements ... was published, here, authored by Member -- redcentre3 -- after successfully following the procedure and installing new Parts to save his 900's Start Clutch.

August 5, 2006

Here's how a member of XJ-Planet replaced his starter clutch WITHOUT removing the engine and splitting the cases. This + SHORTCUT + is used at Yamaha Dealerships. The technician charges FLAT RATE. That means ... He does the job using the shortcut ... but, CHARGES for the work as if it was done -- The Hard Way. I have NOT done this procedure yet. I will employ this shortcut when it is time for me to do the starter clutch ... at which time, I will renew the drive clutches, too!

The member who performed this shortcut had never done the procedure before ... as well. His text appears here as a courtesy to the members of this group from XJ-Planet.

+++ Notes on replacing the starter clutch without engine removal and case splitting. +++

By: Karl Hughes -- karl.hughes @ rmit.edu.au
Edited by: Rick Massey -- xj900owner @ aol.com

Yes, it is possible, (to overhaul the starter clutch without case splitting)* however if you drop the rollers, springs, or spring caps in the crankcase, you going to have to do it the "right" (split the cases)* way anyway...Be prepared....The keys are some patience and go slow...

I'm doing this from memory so if I left something out or you have a
question, please let me know....

First I took off the starter assembly off and the alternator cover
and positioned it aside.

Next you must remove the stator (the big
copper thing inside the cover that spins with/the engine) there's a
bolt in the middle to remove, but the stator has to be pressed off
the shaft, you'll have to have a special tool. (Actual Yamaha Special Tool)*

I've seen them on eBay, but I modified an old harmonic balancer removal tool (the threads were the same)...If you look at the stator it has threads
cast into its housing, thread the special puller bolt into that, and
while turning the puller, the stator will slide off the shaft. (May need an application of heavy torque -- the assembly will "Give" and come off)*

**(Tapping lightly on the puller bolt will often help loosening the pressed-on stator)** -- RickCoMatic

Next, remove the three Torx screws that hold the retainer
plate to the case.

**(These Torx Fasteners are treated with Thread Locker. You will NEED a New Torx Socket and a Hand-held Impact Tool. A used, worn Torx Bit will get you into trouble.) **

Then, the oil spray tube can be removed.

Now the tricky part.

Pull the shaft out of the case (the starter clutch unit will fall down) ((come-out and down))*

Using long screw drivers separate the two half's
of the clutch mechanism.

The half closest to you will have the chain wrapped around it, and half farthest from you (The Starter Clutch)* will contain the rollers, springs, and spring caps.

Using the long screwdriver, hold the farther section up higher than closer, using another screwdriver you can manipulate, and rotate the clutch/roller
mechanism around to remove the three rollers, springs, and caps....A
telescoping magnet will help a lot.

(EXERCISE EXTREME CAUTION WHEN REMOVING THE SMALL PARTS.)*

Reassemble the opposite of removal, go slow, make sure both halves of the clutch mate together properly, use a dab of grease to hold the springs, and caps together....

I will also add as a side note, as it may or may not be required to
do so, but I did have the trans clutch removed while doing this.

I also unbolted the idler gear that goes between the starter and the
starter clutch (this is done from the trans clutch side).

The idler gear will fall down an inch but can easily be manipulated with
magnets and screwdrivers.

+++++ End of text by Mr. Hughes +++++

Following added by me for your special attention.

Sacrifice a bed sheet. Cut the sheet into a LONG 2-inch "ribbons"
Use lengths of the long ribbon to STUFF into the cavity to PREVENT anything from (DROPPING) entering the engine cavity. STUFF long length of the ribbon into voids -- Tightly! When you have successfully dealt with those small parts that might "GET AWAY" ... you can easily remove ALL the safety stuffing by withdrawing the ribbon from the cavity.

If you drop anything into the cavity ... the SHORTCUT is OVER and you'll be needing to remove the engine and split cases to finish the job and retrieve those parts that fell into the engine cavity.

*Portions added / edited by Rick Massey

It's straight-forward wrenching until you replace the springs and rollers ... then, you need your Open Heart Surgeon hat on!

Best of luck,

 

You won't leave it Rick, will you, gmoncrief, there is NO quick fix.
Couple of points, when you get to:
Pull the shaft out of the case (the starter clutch unit will fall down) ((come-out and down))*
Using long screw drivers separate the two half's
of the clutch mechanism.
The half closest to you will have the chain wrapped around it, and half farthest from you (The Starter Clutch)* will contain the rollers, springs, and spring caps.
Using the long screwdriver, hold the farther section up higher than closer, using another screwdriver you can manipulate, and rotate the clutch/roller
mechanism around to remove the three rollers, springs, and caps....A
telescoping magnet will help a lot.

You will find you are looking at the BACK of the clutch, i.e. you can't see, touch, feel, the rollers & springs.
AND:
Sacrifice a bed sheet. Cut the sheet into a LONG 2-inch "ribbons"
Use lengths of the long ribbon to STUFF into the cavity to PREVENT anything from (DROPPING) entering the engine cavity. STUFF long length of the ribbon into voids -- Tightly! When you have successfully dealt with those small parts that might "GET AWAY" ... you can easily remove ALL the safety stuffing by withdrawing the ribbon from the cavity.

If you drop anything into the cavity ... the SHORTCUT is OVER and you'll be needing to remove the engine and split cases to finish the job and retrieve those parts that fell into the engine cavity.

This is not right, just drop the pan & you can feed them suckers in the top & out the bottom all day long.

 

Once again.
To make it perfectly clear.

I ... have ... NEVER ... done ... this!
I took notes while having the process explained to me by a VERY WELL QUALIFIED adviser.

I wrote-up the process from the notes and SOMEONE ELSE used the process to FIX his Bike.

It worked for him.
Worked for another who dealt one-on-one with the fellow who used the shortcut and successfully restored functionality to his starter clutch.

Since I published the process directly from notes taken while interviewing an eminently well-qualified, multiple award winning, career Yamaha (Factory-trained) Tech, who explained the shortcut while I wrote-down his remarks; two people tried it.

Two people fixed their starter clutches.
Two for two.

 

Who's the two, red centre is like the guy who works down the chip shop, who is the other liar?

 

http://en.wikipedia.org/wiki/Duel :lol:

Rick's post is well meaning....

I wonder if an attempt should be made using that method, if it fails is it then only a case of splitting the cases - that is, the work already done would be part of a split case exercise anyway?

 

I've tried it adrian, word for word, only the words are wrong.

 

Because somebody did something you can't do ...

DOES NOT QUALIFY >> YOU << to call them "Liars".

Shame on you, man.
See if you can get back near 120 over 80.
Don't explode.

 

Until you have tried it yourself, what you say don't mean squat.

 

I have no need to try it.
I doubt I ever will.
If my Starter Clutch goes south, tomorrow; I'd put the bike up for sale.

I'm sorry you're bitter over an article I very carefully researched and wrote five years ago.
That's your prerogative.

But, this still leaves you short one apology to the member you insulted and called a liar.

 

He lives nearby, he can come on down & I'll tell him in person, who is the other cove ?

 

Here's the POST from 2006 & the offering from bike-man-man bears an uncany similarity to the RickCoMatic post, what is most interesting is the last post when he is asked if he could turn the s-clutch around in there to get to the rollers, the answer was not forthcoming, 5 years & waiting.

 

listen up, i'am going to tell younz how to walk across a bed of red hot coals, listen close 'cause i'am not going to do it you are

 

I've tried my darndest to manipulate the starter clutch using just two bare crankcase halves, the jackshaft, the crankshaft, and the hy-vo chain in place (that's it, no other engine components installed), and then pulling out the shaft, and I'll be a monkey's uncle if I could ever figure out, see, or even imagine how this trick could ever be performed..........it all sounds very nice in theory, but in practice, there's just not enough room to get in there and manipulate the starter clutch to the point where you can access the springs/rollers/pins to remove them (if they're stuck) let alone replace them.

I'll give the first person who can show it being successfully performed, on un-edited video, in the manner described above, a $500 credit towards parts purchases.

 

Ah, a voice of reason, no one knows better than Len that the starter clutch is bolted from the far side, with locktite & you can't even SEE the rollers or pins.

 

http://www.youtube.com/watch?v=fh0F1glgKBk

 

I have a question, and I'm not trying to be a wiseguy, just understand this a little better.

I was under the impression that the most common failure of the starter clutch was splitting of the sprag housing portion ("starter clutch outer assembly" in the fiche) at the ends of the slots where the rollers ride.

Again, according to the fiche, the screws face the right side of the bike while the described procedure involves coming in from the left. I don't see how it could possibly be done as described either.

Wiz had a thread a while back wherein he bashed a large chunk out of the case casting and came in from the right side to change the starter clutch; but I don't believe it only needed rollers and springs.

So I guess my questions would be: Even if you could change rollers and springs via delicate surgery, how commonly are rollers or springs the actual failure? If the common failure is the sprag housing, then the whole thing's gotta come apart anyway, right?

 

Shortcuts rarely lead to less work in the long haul. Fix it right or dont fix it. I was laughing in another thread someone flipping an entire bike upside down to work on the transmission. The lengths some people will go to find a "shortcut" astounds me. In the end it rarely ends up any easier.

I have the symptoms of a failing clutch myself on one of my motors. I took the time to get in there and see what the "brain surgry" would entail, and quickly said to myself F that! To me it looks like the putting yourself through unreasonable amount of stress, just to have to split the case anyway to do the job right.

 

When you go apologize to Karl; bring-along a notebook and a pen.
Have him explain just exactly what he did and write it all down.

I'll revisit Yamaha with the comments this has generated and see what the Tech who I interviewed has to offer.

We can then report on our findings and attempt to bring this matter to a close.

 

Fitz, sometimes they are, you're right, although sometimes the crack is not significant enough to prevent the clutch from working. I think Polock has a couple of pictures posted on another thread showing what he found.

By the way, having the clutch assembly (primary drive gear) out doesn't help much, if at all.......the starter clutch won't "fall down" far enough for the removal of the primary drive gear to be of any use or benefit.

If I recall correctly (it's been a while since I did the trials-and-tribulations thingy), the only way you can achieve the "engine assembled" repair to the starter clutch is if you remove the oil pump, the main drive axle shaft, etc., and then you can (I think) weasel the starter clutch out of the bottom of the engine. But removing all those components without splitting the cases just seemed like much more effort than doing it "the hard way".....


STARTER MOTOR CLUTCH REBUILD PARTS:

sms6) OEM and aftermarket parts to rebuild your STARTER MOTOR CLUTCH DRIVE. Yamaha used a "centrifugal clutch" type of drive system to engage and disengage the starter motor drive from the engine gear, and over time the springs, spring caps, and roller pins that provide the engagement action can fail....which is terrible, as these are a real pain to replace, and almost always require dis-assembly of the upper and lower engine cases.

However, there are a few alternative methods that might (or might not) save you some incredible effort and allow you to "dodge a bullet" and repair your starter clutch system in an easier manner; but, the success of such methods really depends upon whether the clutch failure is due to mechanical wear or damage to the pins, caps, or springs (in which case, you MUST somehow get in there and replace those items), or, if the caps and pins are merely "seized" in the starter clutch hub due to accumulated varnish and sludge, etc.----and in such a situation, then you might be able to clean out the mess and restore the clutch to an operational condition.

Methods a) and b) below address the problem of "sludge-seized" component pieces. Method c) deals with the problem of damaged parts. Note that if any of the major components are damaged---the clutch hub, or any idle gears or sprockets---then the engine is going to have to come out and taken apart to allow access to such larger pieces.


a) Pull the starter motor.....or, even better, the alternator shaft housing.......and shoot lots of solvent (seafoam, carb or brake cleaner, etc.) directly onto and into the Starter Clutch Assembly

Then, drain all of your engine oil and refill with fresh oil. Run the engine while on the centerstand until it's warmed up, drain the oil again, and fill with fresh oil.

If the starter clutch was just sticking, this method may wash away enough of the accumulated gunk and set you on your way.


b) Next, it may be necessary to actually run a solvent in with the engine oil in an attempt to loosen any engine oil sludge that has accumulated over time, and locked the starter clutch roller pins. Of course, such solvent should be run in the engine with the bike on the centerstand, and not any under load!!! Then drain and flush this solvent-and-oil mixture, refill with fresh oil-only, run on the centerstand again, and then drain and refill with fresh oil-only again......now you can ride it again. You want to make DARNED SURE that you get all of the solvent-saturated oil out of the crankcase before you put the engine under load, and risk chewing up engine bearings, etc. with solvent-thinned oil!


ALSO, TAKE NOTE OF THIS EXPERIENCE FROM ANOTHER XJ-OWNER:

"If there is not enough grip between the plunger and the roller, it can skip, causing the grinding, clacking noises you hear. I have been told by a Yamaha mechanic with over 20 years experience that it is very possible for some synthetics to greatly increase the chances that this will occur......"

So this weekend I drained the synthetic out, put some cheap 20W50 in, and rode it for a little while. Then I drained the cheap oil out and put Castrol GTX 20W50 in and the starter does not malfunction anymore, not even once! I cant believe it! I guess these bikes were not made to run synthetic---I'm sticking with conventional oil from now on."



c) If none of the above solutions work, then it might be time to do the dirty deed.....the engine will need to come out of the frame and be dis-assembled to access this area. If you read this thread:

http://www.xjbikes.com/Forums/viewtopic/t=1700.html

you'll get a good idea of what challenges you're up against.


By the way, if you do decide to split the engine open and perform open-heart surgery, you might as well replace the primary chain and guide while you're in there, as those are also "wear items" and will cause problems if and when they start failing!



Starter Clutch Components and Operation:

The general layout of the starter motor clutch system is as follows (it differs slightly between the various engine types, but overall, here is what is happening):

a) the starter motor gear operates upon a PRIMARY IDLER GEAR (which is supported on its own shaft)....

b) which in turn spins the another INTERMEDIATE IDLER GEAR attached to the rear side of the STARTER CLUTCH ASSEMBLY.

c) This entire "starter clutch assembly" consists of the above intermediate idler gear and a CENTRAL HUB UNIT which contains the centrifugally-operated springs, caps, and roller pins which lock the starter clutch operation to the starter motor. Failure of both the hub unit itself (it can develop hairline---or larger----cracks over time) as well as wear or seizure of the springs, caps, or roller pins accounts for 99.9% of all starter clutch problems and failures.

d) The "central hub unit" is attached via rubber ABSORBERS operating on the STARTER WHEEL to the starter clutch OUTER COVER, and this outer cover has a DRIVEN GEAR which is operated by the PRIMARY CHAIN (a special link-less chain, called the "Hy-Vo" chain).

e) The starter clutch assembly rides upon the same shaft that drives the alternator.

f) If you are going to have the starter clutch assembly out of the engine and available for rebuild, we suggest that the central hub unit be inspected carefully for any damage or cracks, and replaced if needed. Here is a common problem that you need to look for (scroll down for the image of the cracked hub):

http://www.xjbikes.com/Forums/viewtopic ... t=555.html

Also take note that if the hub is not cracked, there is some good advice about re-conditioning the hub that you may wish to follow.

If the hub is secure, then always replace the springs, caps, and pins, as well as the rubber absorbers used within the starter wheel.

 

As far as I'm concerned it is finished, you were sold a dud, take your licks & get on with life.

 

Like I said, ...
I have plans to revisit the matter and publish my findings.

Once I have clarified the matter to my satisfaction and make any appropriate revisions, additions or issue a corrrection; I'll be done with it.

Let me see what the Yamaha Tech has to say.
Present his side of the story.
- 30 -

 

Here's one I pulled out of my '85 XJ 900

 

I was under the impression that was the most common failure, not the rollers or springs.

 

Yes Fitz, rollers & or springs will make it noisy, the crack = catastrophic failure.

 

while your shortcutting it up, dont forget to change that primary chain guide

 

S*** Polock, yours was worser than what mine was. (

 

Gadfrey. That one looks like it coulda come out of a Virago.

I understand the V-Twin "kickback" doing that, but what is it that makes it semi-common in the big fours?

Or is it just a marginal bit of engineering, no matter what application? The piece itself is nice and beefy, but apparently weakened by the presence of the spring "pockets." Looks to me like it should have been a third again thicker.

 

Well, when you think how these things work, by wedging a roller into a tight corner with masive force, failers are bound to result.

 

The stresses placed on the assembly by negligent over-use trying to get a bike with an ignition problem, ... or a severely out-of-tune bike started by engaging the starter motor for much longer than necessary whilst cursing and simultaneously applying "Plunger-top bending force" to the Enrichment Circuit lever, ... until the last-gasp of the battery has just enough current to engage the starter, ... but not rotate the engine against is compression ... but, the PO thinks it will go if he gives it another second or two.

 

I'll bet if the whole thing was 1/3 again thicker, providing extra "meat" on either side of the spring pocket holes, they wouldn't crack. It's not from running the starter too long, it's from an opposite force "banging back" against the engaged sprags. Understandable in the Virago, it's like trying to kickstart two big singles at the same time.

I wouldn't have thought the fours would beat on it that bad; and obviously, neither did Yamaha.

Makes me love my 550s that much more.

 

That's what I tried to convey.
COMMON among bikes that fail to start.

If your bike is tuned-up nicely and starts immediately, ... you're not likely to have a Starter Clutch problem.

But, if you abuse the mechanism, repeatedly overworking the assembly, ... failing, until the battery dies, to get a bike started, that has issues preventing it from running, ... you're begging for a starter clutch failure.

 

I understand that even top notch wrenchers like
yourselves can, will and do have a diffferance of opinion.

But the anger is unhealthy. I believe all of you have respect
for one another. It would better if that was stated when giving
a descenting opinion. That way feelings wont get hurt and the
subject at hand can be disscused at length in the spirit it was
intended.

It would be a shame if we lost the skill/knowledge of one of you
due to an opposing point of view.
.

 

My starter clutch is fairly bad, and has been for the 2+ years I have had it.

I have put up with it due to the fact I have been getting organised to fully rebuild my spare engine. The spare engines starter clutch is perfect, but I have purchased (from XJ4Ever) springs pins and rollers to do them anyway.

Once the engine is removed, I may try to replace the starter clutch components without splitting the cases just for the exercise, to see if its possible. If I do it, I will take some endoscope pics that should end speculation on how possible it is to do.

I wonder if mine has cracks though... If it didn't have crack 2 years ago, it may have now, but not not from hard starting, it would be from the starter going - spin spin - smack, spin spin - clunk, spin spin - shudder-clunk for 2 years.