Archive for the ‘clutch’ Tag

XS650: Troubleshooting Manual   Leave a comment

If you have ended here and not where you want to go – VOU HAVE A VIRUS ON YOUR COMPUTER … do us both a favour and scroll back to my blog post Virus. Please read this then do a search as suggested.

Yamaha Troubleshooting Manual

In 3 languages. English. French. German

Troubleshooting Manual

Yamaha Troubleshooting Manual

Trouble Shooting

– hopefully this can prove organic … comments and suggestions – correcting, extending
– an engine is basically an air pump – 4 stroke …  suck, squeeze, bang, blow
– add fuel, timing and spark = internal combustion engine
– break this system anywhere and you wont get much action

– so your engine turns over ? wont start
– what have you done ? what have you changed, altered, played with, unfixed ?
– air ? fuel ? spark ? …all in the correct ammount and moment ?
– don’t panic…turn the key and petcock/s off, step back …take a breath-deep, go do something you really enjoy for a couple of minutes…

  •  fuses ? kill switch ?
  •  battery ? 12.6 V ? put it on charge, brushes ? check charging system
  • power to coil/s ? points spark ? plugs ?
  • filters ?
  • fuel to carbs ? bowls ? cylinders ? floods ?
  • compression ? leak-down test ?


  •    adjust your cam chain … can readjust warm once you get her running
  •       set your tappets
  •       set your points if you have them .. plugs


– once you get this far she should be at least spitting and farting enough to attempt setting your carbs …

  • if she wont idle, look for air leaks ? atu ? massage her pilot jet circuits
  • once you can get idle, do the idle speed screw/pilot air screw dance
  • smooth transition through to full throttle ?
  • synchronise

Electric Troubleshooting

Carburetor Troubleshooting

Starting System Troubleshooting

Engine Troubleshooting

Oil Troubleshooting

Clutch and Gearbox Troubleshooting

Frame Troubleshooting


XS650: Hydraulic Clutch   Leave a comment

After handling related modifications this, to me, this makes good sense. Self-adjusting. Direct. Simple.

The first ones I saw were Kawasaki GPZ slave cylinders and matching master cylinders. Easy. Cheap. Effective. Means modifying the left hand engine cover. Opening out the hole. Sanding a flat spot on the case outside. Drilling for mount screws. Making an adapter for the push rod. Install. Bleed. Check. Use. A day-no problems.


GPZ900 slave cylinder


I have a unit that bolts directly into the left case. No modifications. Push rod adapter required.


VA (stainless steel) slave cylinder … using tidily small KTM master cylinder … bolts into original case … here it’s test mounted to an old cover that was just hangin around (actually i was about to use the cover as a test mount for a KTM slave cylinder)


slave cylinder … from inside case


setting up a KTM slave cylinder


Or this one. Hidden inside the case.


slave cylinder hidden inside the case … FZR master cylinder


form outside


slave cylinder

Posted December 16, 2012 by xscafe in Motor - Clutch

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XS650: High Ratio Primary Gears   Leave a comment

Years ago Tony Hall used to produce these. They became harder to find than chicken lip-socks (rarer than hen’s teeth). Ivan Hoey (Australia) began producing these once more some years ago. Fits direct to the original clutch basket.

I scored a set and have been running them ever since. Love them. 3 fewer teeth on the primary gear, 5 more on the drive gear. Increases the transmission output while decreasing crank rotation.

Original        … 27:72 … 2.66

Ivan +20%  … 32:69 … 2.16

Together with Terry’s vescanite clutch dampers. The vescanite dampers don’t break like the springs.

Two of the better modifications I’ve done.


original primary gear … with vescanite dampers


high ratio primary gears … with vescanite dampers


Ivan has just produced a new batch. Improved. The inner bush has been replaced with a needle bearing.


Ivan’s new set … + needle bearing


This is a small run. If interested he is now taking orders. Requires a deposit. Email contact here …

He can also do a needle bearing conversion on your stock primary gears. Dramatically improves gear and neutral selection. Also when stationary.

Includes needle, inner and thrust races, thrust washer, 3x screws/nuts and fitting instructions.


convert original primary gears to needle bearing


XS650: Rene’s Dry Clutch   Leave a comment

Rene is a keen Grab the Flag racer. SR500. Winter 2009/10 he began working a 76 XS650 over. 750cc, head, cam, exhaust.

Rene's 76 XS ...145kg dry ... end of 2010, ready for 2011 race season preparation

Rene's SR500 dry clutch, version II, classic cover

His SR500s responded well, over the past 2 years, to his dry clutch. So, he figured, would the XS. Complemented by a high ratio primary gear couple.

cutting the case

seal holder ... from lathe

clutch box welded up

and welded into case ... adapter and ducati dry clutch fitted

and ready to go

Posted January 5, 2012 by xscafe in Frame - Design, Motor - Clutch

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XS650: Dry Clutch   Leave a comment

Hartmut, from Dominator Engineering has a passion for British Bikes. Likes to play in the dirt too. Has an ’84 EML Yamaha Sidecross machine.


sidecross 975cc XS650


Taken out to 975cc. With a high lift long duration cam. Outlandish torque. Pulls from right down deep. Full power beyond 7000 rpm. Often saves gear changes between curves.

Exposed clutch weaknesses. An 8 plate clutch mod and super hard springs was good to 3rd gear. A 10 plate mod with thinner friction plates, ground steels and springs so hard Popeye would have problems was good to 4th.

Luckily he produces clutches for Vincents. Useable wet or dry. And they pass inside the XS650 clutch case. 2 1/2 finger operation. Still going strong at the finish line.

At Schopfheim. Spring. The long straight climb from the start. Over 250m he left the stronger 1000cc machines 30m behind. Bet that felt good.


Vincent clutch


fits inside the XS650 clutch case…hub and basket here


plus plates


and pressure plate


pull mechanism




I know much of this appeared here, but I like this product so much it deserves it’s own post.

Should anyone have interest Hartmut can be contacted here. Dont worry about the site being in German. Hartmut has no problems with English.

Posted June 24, 2011 by xscafe in Motor - Clutch

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XS650: Clutch Assembly   Leave a comment

The bean counter was here. How do I know. In their wisdom, Yamaha left a Thrust Washer off the diagrams. It was there in their original manual. Then it disappeared. Between hub and boss they show a washer (25-50-2) and a thrust bearing – missing the washer (31-51-0.5) between needle bearing and hub..(e)..

correct diagram…shows the missing washer between basket and hub


section view


the raw product


Don’t forget the primary springs. Bits in the sump and filter. Clutch complaining. Broken springs. Can be replaced. I called Terry and ordered his vescanite blocks. I have no complaints.

the springs in the primary commonly break…a must do


While you’ve gone this far check the shift shaft and selector springs. They weaken and affect your gear changing. To fix you have to strip it all down anyway. I keep a bag of springs and simply replace them when I’m there.

the springs..selector above..shift shaft just poking its nose out from behing the clutch


make sure the adjustment is right




ready for first washers…25.2 x 36 x 1.0 : 25 x 50 x 2.0 then the bush


in that order…the smaller first, sits on the bearing outer


Look for wear on the edges of the basket and boss…can lightly file smooth…remember though, the more you take off the more play the clutch plates will have.

thrust bearing and its’ attendant washers…35 x 51 x 0.5 : thrust washer : 25 x 50 x 2.0


if you have it use the new thrust washer with more needles…the washer is the missing thin washer…comes as a set




then the boss…18mm…55-59 ft/lb…80 N.m…8.1 kg/m


there are 2 usual ways to secure the boss..2 washers and a nut…or lock tab and larger nut…where is the ball?


Load up the plates. First a friction then a pressure.

Then the pin that pushes the pressure plate. Don’t forget the ball like I have here.

Then fit the pressure plate. If the boss has a mark on it, it must line up with the hole in the pressure plate. If there is no mark, look at the pressure plate screw receivers in the boss. There is only 1 that lines up exactly with the centre of a tooth. It is important to mark this and line this up with the hole in the pressure plate.

these marks or points MUST line up




early p.p have no teeth…the teeth must locate at all times in the boss


i like to use these…allen head screws…dont strip the head and get a better feel


and looks like this…tighten with impact driver – 5-7 ft/lb…9.0-9.5 N.m…0.8-1.0 kg/m…use #3 bit so you dont damage the phillips head if using the originals


dont forget to check your clearances


push rod seal commonly leaks


check the push rod seal… lhs…here is a kit that replaces the original seal with a generic


This one from Twins Inn.

the push rods…dont forget the balls .. 5 16ths .. or replace the 2 smaller rods and a ball with a longer one


check the worm gear for function…the female part breaks-hard to see in all the crap-so clean it and lubricate…dont lose the bearing from within the male


look at your cables…clean and lubricate…this motion pro one is heavier, stronger and doesnt have so mush rubbing in the bend



There are 3 variations. Pre 73, 6 plate pack : 73-78, 7 plate pack : post 78, spring loaded 6 plate pack.

The different packs, 6-7-6 plates, are interchangeable as a unit. The early, thicker plates (3.5mm) are not available anymore. If it hasn’t already long been done the rubber rings are removed and extra steel and friction plates are installed.

The 7 plate pack is known to increase risk of primary gear dampening spring failure.

Steel Pressure Friction
Pre Aug 73 1.6mm 6 @ 3.5 mm
Aug 73 – Aug 78 1.4 mm 7 @ 3.0 mm
Post Aug 78 1.4 mm 6 @ 3.0 mm

My personal suggestion is to change in a later model 6 plate pack – straight swap.

When installing:…

  • soak new friction plates in oil-overnight if possible…Note that your bike needs 20W-40, which is available at truck stops and auto stores…eg Shell Rotella, Pennzoil without the additives found in modern automobile motor oils. Wrong oil = clutch problems…big time!!!
  • check steel plates for warping-lay on plate glass, if you can rock it or slide a 0.008″(0.2mm) feeler guage under, replace
  • buff the sharp edges smooth…as these are stamped-out, the top edges are rounded by the die, the bottom edges are left sharp…buff these smooth with a wire wheel
  • scuff the surfaces lightly with emery paper to remove glazing – wash
  • check friction plates for wear…new-3.0mm…min-2.7mmm (earlier, 3.5mm new/3.1mm min)
  • lightly bevel the edges of the friction plate tabs with a file…this helps prevent them catching on the basket fingers

NOTE…when installing the later sprung 6 plate pack, be aware that there are 2 different steel plates…the plate that belongs to the anti loading pack that goes into the boss first, is thicker than the others, 1.6mm as opposed to 1.4mm – dont mix them up

Posted January 19, 2011 by xscafe in Motor - Clutch

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XS650: Clutch Basket Tool   Leave a comment

There is only really one special tool required here. To hold the basket. While you remove the boss nut.

If I remember correctly there are 2 different sized nuts. The earlier was 27mm and used a locking plate. Later nuts, 29mm, used lock washers.

An air gun will mostly spin the nut off easily simply holding the basket with your hand and a rag.


low tech…you may get away with it once or twice…you may not


tension is not your friend


I know it’s low tech. All the materials will be in your garage. But dont do this. You are putting tensive force on the basket. Those tangs on the side. You will break one.


also low tech…wood or plastic wont score the metal…imagine being those bearings though…


Also common. Stress loading the bearings. Do you really want to do that to the end of your finely balanced precision instrument? Your crankshaft.


got some old plates?…let the chain and gearbox hold the clutch


then there’s this…looks good, known to bend, easily


home made, old pressure plate, works, still not stable enough for me…weak handle


someone is using their head…email address in pic..on ebay too


Now. While you have this off:

  • Check for broken primary gear springs
  • Check or replace the thrust bearing with a multi-needle one
  • Don’t touch the screw for the plate holding the e-start transfer gear. The gear on the other end of the shaft simply sits there. Move the shaft out and this will release. It wont go back in. Pull the crankcases apart.
  • Replace the shift shaft and shift select springs. Cheap. insurance.

thrust bearing…more needles


that screw bottom centre…don’t touch it….too much gasket…the shift shaft spring is there too


selector spring at the top…shift spring just poking its head out from behind the clutch


Posted January 18, 2011 by xscafe in Motor - Clutch, Tools

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