How to replace your sprag clutch.

[go_modem_go]

There are no left hand threads on these motorcycles. None.

I just found out that there are at least three left threaded parts on a Rotax V990 engined Aprilia - on the Falco gear lever rod, the front ball joint thread, rod thread and stop nut are left threaded!...


Digging up this topic:

I'll be attacking the sprag clutch repair as a precaution - it's been in there for 12 years and 60k kms now, and gave me the occasional crunch & horrible starting sound on weak battery conditions for many years.... I would need to replace those 8.8 screws anyway...

As to the KTM 640LC4 (and many others) sprag clutch part N° 58440026000: Is everyone's KTM sprag clutch still ok?

If yes, I'll be buying that KTM one, at €70.- incl. shipping and taxes.

It certainly comes MUCH cheaper than the well over $450.- shipped & taxed for the very same part from Aprilia...

PS: Beta Part N° 3625197 000 is the same part than KTM - interchangeable. It is even cheaper, at €53,78 net...

Bikes that have this fitted as well: Beta Motor S.p.A. RR 250-400-450-520 with KTM engines, enduro models 2007-2009. Interesting for Europeans, I guess, since there is probably much more local Beta Motors shops around and about than in the USA.

[kzmille]

I just found out that there are at least three left threaded parts on a Rotax V990 engined Aprilia - on the Falco gear lever rod, the front ball joint thread, rod thread and stop nut are left threaded!...

Well you've got me there.

[DanV990]

As to the KTM 640LC4 (and many others) sprag clutch part N° 58440026000: Is everyone's KTM sprag clutch still ok?

If yes, I'll be buying that KTM one, at €70.- incl. shipping and taxes.

.

I have over 17,0000 miles (27,400 kilometers) on my KTM sprag 58440026000 and it is still going strong. I put it in my bike around 26,000 miles and I now have over 43,000 miles on the clock.
It engages the first time, every time, the starter is used with no clunks or other unusual sounds.

[go_modem_go]

I have over 17,0000 miles (27,400 kilometers) on my KTM sprag 58440026000 and it is still going strong. I put it in my bike around 26,000 miles and I now have over 43,000 miles on the clock.
It engages the first time, every time, the starter is used with no clunks or other unusual sounds.

Excellent.

I just bought the same KTM part, as Beta N° 3625197 000 from a German Beta Moto Motocross Online Parts shop - for €53,78 net, plus taxes and €3,95 shipment.

Let's hope this will last another 12 years and 60k kms, like my first one (which is on its way out).

[go_modem_go]

Hi,

I need to resurrect the thread again - maybe someone can help me.

I f*cked up the flywheel thread with the puller - despite tons of heat, and use of the correct 22x1.5 motorcycle flywhweel pulling tool (Buzetti type). :

Anyway, the pulling tool is stuck in there.... Thread of the Rotax flywheel centre is all mushed up - it just didn't withstand the torque (I used a 70cm torque wrench with 14mm long socket to puller - when it clicked at 140Nm, I continued to apply more torque, flywheel still wouldn't budge a mm...).



PS: The two keys are there due to one of my later (futile) attempts to get the pulling tool back out (keys used as handle whilst wrenching the puller back out... )

1.) How do I remove the flywheel now???


I tried with some wooden support and an iron bar pulling from the back, to no avail (despite 5-10mins of heat to the flywheel centre from a plumbers butane torch). This f*cker seems like welded to the engine crankshaft, but no one has fiddled with it ever before (engine never opened b4!)

2.) I just ordered an entire 2006 Tuono MkII replacement flywheel assembly including gears (10k kms, €110.- shipped - much cheaper than ME / RP used parts!). I wouldn't want to re-use the damaged old flywheel (provided I ever get it off! See above! )....

I know it is a slightly different assembly - hopefully an improved one. Flywheel seems much lighter, but it has a far larger sprag clutch housing plate attached to it in the back.

But: Will a RSV-R / Tuono MkII "RR" 2006 complete flywheel assembly work with the Falco PA, resp. Mille ME / RP 1998-2003 engine stator?



I looks pretty much the same overall size, from the parts fiche the 2006 Tuono MkII stator side looks similar to early Mille / Falco, except the electrical connector. Freewheel gears are the same part N°'s as well, as is the actual sprag clutch assembly (I have a brand new KTM / Beta one in stock, for the future...).

I just hope the crankshaft stub & flywheel magnet inside diameter, magnet depth and stator location are the same for all V990 Rotax engine generations!

Thanks for any tips & hints...

EDIT, PS: I have just learned that the RSV-R "RR" / Tuono MkII flywheel assembly doesn't work on early engines up to 2003 (RSV ME & RP) resp. 2005 (Tuono RP, Falco PA).


Whilst it would fit mechanically, it gives more rev pulses - the Rotax-Bombardier ECM only needs 6 pules per rpm, whilst later engines emit MUCH more than that. This would mess up the engine management... Caponord and Futura seem to have different pulses as well (they use a SAGEM ECM).

[imdrax]

I had a 2002 rsv Mille r that had this issue a while back, I just picked up a 2004 1000r non factory that has a light clanking noise on startup like my old Mille. Is there a writeup for the 2004+ or is it nearly the same as this DIY? Were the 2004+ known to fail jut as commonly as the milles?

[go_modem_go]

@imdrax: Mechanically, it's pretty much the same construction.

The sprag clutch itself is exactly the same one.

What has changed is the mounting flange on the back of the flywheel, it has 6 bolts on the RSV-R RR-type engine, instead of just 3 bolts that were very prone to failure on early bikes (Aprilia used cheap 8.8 bolts in 1998 until at least 2000/01, if not a whole while longer - these can sheer off!). On the RR version, it's also backed by a massive 2nd metal rim - all in all, this looks more sturdy than the flimsy 3-bolt rim on early models.

But I have no idea if the 2004+ RSV "RR" is as failure prone. From a purely sprag clutch point of view, it should be - but at least you won't get sheered off bolts and stuff like that. Also, it's engine / ignition management system is much more sophisticated, hence you may have less off a chance for the engine cranking backwards when not firing up immediately (that's a killer on the sprag clutch!)

[go_modem_go]

Hi,

I need to resurrect the thread again - maybe someone can help me.

I f*cked up the flywheel thread with the puller - despite tons of heat, and use of the correct 22x1.5 motorcycle flywhweel pulling tool (Buzetti type). :

Anyway, the pulling tool is stuck in there....

To anyone who gets into the same mess with a stuck puller screw, I fabricated the solution out of a metal bar, hydraulic jack, triple hook puller, wire and some half-drunken amateur "ingenuity":

Attachment 184682

Link to post in Falco forum

[resqav8r]

Stupeo said "The Aprilia crank holding tool, bought from an Aprilia Main dealer was wrong" .. well that might explain my problem during my 04 RSVR sprag repair.

I may have gotten a lot wrong but doubt it'll affect the repair. The manual must have been written in Italian and translated to Chinese before being translated to English because much of it lacked detail and required assumptions and interpolation (so please pipe in if any of you see something really wrong or has a better suggestion).

My FIRST snag; locate and lock in TDC on either cylinder.
Sounds simple enough .. shift bike into top gear and rotate wheel several times till I know what max resistance feels like (ie valves closed and piston at top). Remove M8 bolt and insert tool ($32 bolt from AF1 http://www.af1racing.com/store/Scrip...idproduct=3168). Problem is my tool (wing bolt) arrived BLACK anodized and although it looks identical and treads in perfectly it may not be holding things as required? (how do I know it went in properly … it’s tightened till the wings catch the casing yet 4mm of thread is still exposed)

I ask this because when I go to tighten the flywheel puller (thanks to this post I’ll apply heat tomorrow) the crankshaft still turns and the piston goes down.

SECOND Snag; the manual does not indicate that the flywheel should be pulled as an assembly with the sprag (i.e., leaving the 6 bolts holding the gear inside the flywheel tightened). I assume I should leave them tight and pull the entire assembly (flywheel, bolts, gear, sprag) as one but I rightly don’t know.

THIRD Snag; Do I assemble the gears and sprag onto the flywheel and then install as one unit onto the shaft … again my manual isn’t particularly clear on this .. OR .. do I install the components onto the shaft and then install the flywheel over the top of them?
T
hanks for your help .. BTW IMO the OEM Aprilia Ignition Cover Disassy Tool -#0277252 is an unnecessary item that does little … I may change my mind after installing the cover but doubt it. Also I saved by using the BMW 650 Sprag but got my gears from AF1 .. which cost TONS more than losthaga & adam indicated on this thread.

[resqav8r]

i have 2007 rsv r bike ran fine to i found out that sprag clutch went out starter just spins

Okay .. this may (or may not) be a clue .. search in this forum for BMW 650 sparg replacement .. I recall that the BMW engine spins in the opposite direction so you must flip all the bearing lobes before installing it on the Aprilia ... DOES ANYONE know if this is he case with the KTM sprag or the DUC sprag?

[resqav8r]

YEP we all got this diagram in our manual but "but tab A into slot B" isn't really much help for me. The 80mm is not enough .. you need 100mm is of help except I'm so retarded that I still need just a little more explaination ... i.e., does this tread into a rotating part of the engine or does it just slot into a bigger opening to prevent moving? If done correct will the crank still turn when I try to tighten the puller onto the flywheel? I assume if it does then my bolt from AF1 is only 80mm and not 100mm OR I've not gotten TDC correct?

[resqav8r]

brilliant (the pic with the floor jack mounted on the side of the bike with gear puller and metal fence post) ... I think at this point I would have just hooked a chain to the bumper of a truck and given it a yank ... hope mine comes off easier

[kzmille]

If the tool wing nut has contacted the primary cover you have totally missed the crank web. should be about 10mm from the cover with the slot engaged. you did not have the engine at TDC.

Nothing personal but service manuals are written for mechanics, not for novices.

You pull the entire assembly and reinstall as a complete assembly.

The tool 0277252 is a handle, nothing more.

[kzmille]

Posted the above after reading only post 159. There are two slots milled into the side of the crank web each one corresponding to TDC on one cylinder.

I have to go help make supper but if you have any other questions I can check in later.

[resqav8r]

Thanks KZ .. yes, I gather that the manual assumes some basic knowledge (I have an A+P) but we all know what happens when we assume so I thought I'd ask and thank you for clarifying .. Guess I'll have to find TDC the old fashioned way by feeling for the piston via the plug hole (so my TD shortcut didn't work). And also thanks for clarifying the part about it going on + off as a complete assembly (the book leads in that direction but doesn't say it). The part about "the Tool" was just me joking because yes .. it's a $40 handle and not a tool ;-) and it may be handy when I put it together. Cheers, AB