Supermoto: sticky accelerator, stiff clutch and kick-start

[byke95]

Hi!

Picked up my XR600R on Saturday and I'm pretty chuffed with what I've got. However, I need help with three problems please:

1) It's got a very sticky accelerator; it doesn't rotate smoothly at all meaning any kind of throttle control is impossible. How do I fix this?

2) You need a grip like Mike Tyson to change gear, the clutch is so stiff; by the time I'd rode it home my hand was killing me! Is there an easy way of loosing this up?

3) Ah, the kick-start. I know there is an art to learn from this and I will get it, eventually. Thing is, the guy I bought it off didn't offer me much advice, at the moment it's taking me 20 mins to get it started. I'm not sure about this piston/ignition start thing and how the compressor lever above the clutch lever helps?

Thanks for the help!
Phil

[finpos]

Are the clutch and throttle both cable operated? Sounds to me like a typical case of somebody has dismantled it at one point and re-assembled it with the cables routed wrongly. Makes much more of a difference than you'd expect. To test it see how difficult it is to move the clutch lever (i.e. the thing that sticks out of the engine at the other end of the clutch cable)

Starting it - set the compression lever to its start position. SLOWLY press down on the kickstart until you feel the piston at the top of it's compression stroke ( i.e. at maximum resistance - bit of art involved, you'll know when you've gone too far). Then let the kickstart return to the top of it's stroke. Then the aim is to kick the lever as FAST as you can. If/when it starts, put the compression lever back to normal.

Nb - how the compressor lever helps - it reduces the amount of compression in the cylinder. On "full" compression you'll be struggling to move the piston past the top of it's compression stroke. Not normally a problem on 4 pot type bikes because of the different compression and engine geomotry. i.e. your big thumper will produce a shedload of torque, which means you're going to need a similar shedload to get the thing started.

And don't forget the choke, if it has one.

fin.

[byke95]

Thanks for the help fin!

I'll have a look at the clutch cable tonight. By moving the clutch cable at the engine end I guess I'm looking for movement at the handle bar end? If there is play and they are connected correctly, what then?

So, starting the bike:
1) Choke out, compressor down
2) Push kick-start lever until I feel resistance (i.e. it's at compression stroke)
3) Kick lever fast and hope for the best!

[stinkwheel]

Cables could also just want oiling?

Wear big solid boots for kick starting a thing like that. You might need more than one press of the kickstart to bring it up to compression. You will eventually learn where the 'sweet spot' is for this (some bikes used to have a window into the crankcase you could line up a mark in, XT500 for example).

Once you are at the 'sweet spot', let the kick start return to the top. You now need to give it some welly, really swing that engine over, don't be half-arsed about it or the bike will kick back and it will hurt (hence the boots). A single big kick with a lot of weight pressing down on the kickstart and swinging it through its full arc, if you watch 'old hands' at it, you will see both feet are off the ground, this takes a certain amount of balance.

If it doesn't fire up, start again.

You really want to be sat astride the bike for this, I see people trying to start big singles while stood next to them and it doesn't work.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[finpos]

Sorry didn't describe that too well. Now it's lunchtime I'll give it another go.

With the clutch/throttle cables you're basically trying to find if there's a lot of resistance in the cables. If they are in good condition and properly routed, there will be very little. Try to move the clutch lever at the engine end. Note that this might be a bit harder than you want because the clutch lever on the handlebars gives you some mechanical advantage. Normally I would jam a spanner into it somehow to double it's length - then it should be fairly easy to move.

With some contortion you should be able to hold the tension off the clutch cable like this - then try to pull in and push back the handlebar lever. It should move smoothly and with very little effort..

Also look for any kinks in the cable - they should run in nice, smooth arcs. Often, people put aftermarket handlebars on - and they are too long for the existing cables, so they get re-routed on the wrong side of the headstock causing all kinds of problems. I don't know your bike at all, but normally the clutch cable goes to the right of the headstock and the throttle cable(s) to the left. Check in the manual or on a "working" bike for the correct route.

It's also a possibility that the cables are just corroded or badly lubricated, but I'm not sure if that is realy such a problem these days with the coated cables that seem universal now.

Starting - slowly push the kickstart to just at compression, then let the kickstart lever return to it's top position, then kick like hell.

fin.

[G]

I agree with what is posted above, but some other thoughts as well:

Throttle:
Is the bar bent at all? This is a common cause of 'sticky throttle'.

I recently replaced the bar on my TRX. It wasn't actually bent at a point that would have caused the throttle to be sticky. However on the new bar I pus some spray-grease. It now has a very free movement, almost too free I would say!

Clutch:
It may just be that that is the way it is - big singles clutches are usually quite heavy as standard, so it depends what you're used to.

On my first dr600 I would often have to jump up with my left foot, right kept on the kickstart. As I come down, also push down with my right foot on the kickstart. I'm a chunkyish and not too badly built 13-14st, which helps.

First time I had to kickstart the DR it did take 20 mins or so, but got used to it faily quickly.

[byke95]

Brilliant, thanks for the help guys, I'll put all this into practice!

I think weighing 68kgs isn't helping the kick-start process, time to start working on the legs at the gym!

[G]

[byke95]

[cagiva gezzer]

If you've got weak hands, try one of these

https://www.motoworldracing.com/media/Moose/moose-EasyPullClutch.jpg
____________________
"because one stroke isnt enough and four strokes waste two"