A W.O.T. Question

[IanDMacDonald]

So, getting on the highway and I crack the throttle wide open, the bike catapults forward, but once it hits around 7k rpm, it shoots to almost redline with all engine noise rpms, and which does not seem like the power is going to the wheel yet, and then it seems like the engine catches up and the rpms fall back down to where the wheel is spinning at. Does this make sense?

[TopCatGr58]

Hey Ian,

It makes perfect sense....that your clutch plates are slipping....so when they break loose, the rpms rise but the bike doesn't go any faster....then they slowly reconnect/grip and the rpms come back down to match the actual speed! Get some HD Barnett Springs.....but adjust your clutch first at the engine!!!

T.C.

[BA80]

Slipping clutch.

Have you put heavy duty spring in the clutch and (here we go again) what oil are you running?

[BA80]

Oh yeah and like TC said, check your adjustment.

[James England]

I'd also take a look at the plates, both friction and steel ones. Remove any tarnish or deposits from the steel ones with very fine emery paper and check that they are not warped by laying them down on a flat surface and checking to see they are flat. The friction plates should also have a reasonable amount of friction material on them and no evidence of overheating or damage to the friction surfaces...a shiny, glazed appearance on the plates means you should give them some attention.
But, as TC said, check the adjustment first...at the engine end, then the handlebars. It may be too tight by a fraction. If not, new springs and a clean up of the plates will probably sort it out.....

[BA80]

There generally isn't any issue with the plates if the adjustment is right, the springs aren't weak, and the oil isn't full of additives that don't play well with wet clutches.

You REALLY have to smoke a wet clutch to damage THE PLATES.

[motoman]

+1.....U will litterally have to see smoke coming off the clutch cover before questioning wet clutch disc wear.

That referance is more towards the moto-X world, which just means you were riding competitively and aggressive as you should be doing.
Maybe not quite to that extent on the street, but same idea prevails.

[IanDMacDonald]

Very interesting. I thought it was more a carb issue. Like, too much gas for the engine to combust.

[James England]

The steel plates do get shiny with deposits though, I've found. I had bad clutch slip on the XS with nitrous and cleaning the steel plates and renewing the springs with 10% stronger ones cured it..

[IanDMacDonald]

So, why does this only happen when I rip on the throttle wide open versus running it quick but not wide open? No other symptoms of a slip besides a false neutral.

Note: I am running Rotella T5 15w-40. Next Spring wil be Castrol 20w-50.

[BA80]

You generally won't notice it in 1st, 2nd, and maybe even 3rd but it will show up as the engine is working harder to accelerate at full power in the higher gears.

You still have the same horsepower but the rear wheel gets harder to turn.

I used Rotella in other bikes and it worked fine but the XS is a little more touchy that way. The clutch is actually too weak for the engine. Try running some different oil in it. 20W50 is what it needs but it can have no friction modifiers in it. The API sevice label should look like this



The bottom of the circle blank. Walmart house brand 20W50 works fine. I think it's called "Tech" or something like that.

[IanDMacDonald]

Yeah, Super Tech. Blue bottle.

[BA80]

Yeah, that's the fella. Change the oil and filter and after about 50 miles or so the slipping should go away as long as everything else is good.

I do suggest strongly that you put some heavier Barnett springs in also. Night and day difference.

http://www.powersportsuperstore.com/...tm?Click=35177

[motoman]

So, why does this only happen when I rip on the throttle wide open versus running it quick but not wide open? No other symptoms of a slip besides a false neutral.

Note: I am running Rotella T5 15w-40. Next Spring wil be Castrol 20w-50.

The T5 has friction modifiers, and wet clutches don't play well when that is in the mix.

[650mark]

oil?

Rotella T 15w-40 is JASO MA rated, has no friction modifiers(lower half of the API circle is blank). a gallon jug of it sells for about $20.00 most places. I find it works well in my '80 special, at least as well so far as the much more expensive "motorcycle specific" oils I've used. of course, ymmv.