Unique transmission problem on custom S2R

deftone · December 08, 2009, 06:30:40 PM

Ok, to start i have my buddies 05' S2R 800 that was converted to a dry clutch by previous owner (i would highly discourage this conversion to anyone thinking about it). Travis from the former corse superbikes in WI did the conversion...it looks well but we've had it back to him on 4-5 different occasions for mostly oil getting past the retro fitted seal....well recently corse superbikes has shut it's doors and i don't have travis's contact info...so here i am

the new problem (besides that it STILL leaks oil) the trans feels like it's hanging up...specially noticeable in 1st gear but after further testing it does it in every gear...i release the clutch and the bike begins going forward as usual and once the revs get up to about 2200 there is an abrupt lunge to about 3k....it is a bit scary going around a corner at moderate speed if the revs drop down to the mid 2k's (in other gears as well)...the clutch and trans i believe are out of a 916 but not 100%....does anybody have any clue what this might be....i took the whole clutch apart and case cover and spotted the the cush drive hub (which this set up is not a cush drive) showed signs of rubbing against the clutch housing...other than that everything seemed normal....recently the the pressure plate powdercoated so the pushrod was out and i re-bled the slave cylinder ....other than that the last it was driven was by corse superbikes to fix the constant leak...i don't think it's the push rod because the bike does the same thing in 2,3,4,etc. gear if i drop the revs down below 2800....

any help is appreciated

p.s. does any one have the manual for a 916 that could send me the clutch pages...i think this thing is missing a plate but i'm not sure if it is intentional or not....

Speeddog · December 08, 2009, 08:28:53 PM

Transmissions from the large-case motors (748, 749, 848, 851, 888, 900, 916, 996, 998, 999, 1098, 1198) won't fit the small-case motors (400, 600, 620, 695, 696, 800).

It does sound like there's something wrong with the clutch.
But I've not heard of symptoms like that.

Does it grab again at 3k rpm?

monsta · December 09, 2009, 02:40:40 AM

Quote from: deftone on December 08, 2009, 06:30:40 PM
oil getting past the retro fitted seal....well recently corse superbikes has shut it's doors and i don't have travis's contact info...so here i am

sounds like the housing may need re-machining to get the seal to fit properly?...

the new problem

new problem? was this problem there from the time you got the conversion done or has it developed?

(..i took the whole clutch apart and case cover and spotted the the cush drive hub (which this set up is not a cush drive) showed signs of rubbing against the clutch housing...
how hard do you think its rubbing?

deftone · December 09, 2009, 08:46:22 AM

Speeddog

it grabs fine at 3k and pulls no problem after that. So that ruled out the clutch plates to me. But they do appear to be a little worn. Not horrible though.

Monsta

the oil leak is something I think I might be able to tackle. After I got inside it more I realized i might be able to try something new since it appeared that it was coming out around the splines.

New problem started since the last time we picked it up. The place was going out of business and we took it up there cuz Travis said he talked to someone at a ducati mechanics seminar that did a similar conversion. Anyways we picked it up and my buddy hired me to do more custom work to it (cosmetic only) so it was never really ridden since we picked it up from the last fix. I'm not exactly sure what he did the last time to "fix" it but it obviously didn't work(cuz there is still oil coming out) and now there is the new problem. It did not do it prior to the last Travis "fix"

rubbing is noticeable, as it rubbed paint off the hub and and clutch housing.

dlearl476 · December 10, 2009, 11:22:41 AM

Stupid question: It's leaking oil... Did any get on the clutch plates?

deftone · December 10, 2009, 06:25:51 PM

the oil does get on the clutch plates a little but not enough to make a difference...

deftone · December 15, 2009, 06:15:05 PM

anybody have any other thoughts on this?

Speeddog · December 15, 2009, 06:50:29 PM

Is it a slipper clutch?

deftone · December 15, 2009, 06:57:04 PM

nope, at least it doesn't appear to...and it does not have a cush driven primary either

Speeddog · December 15, 2009, 07:19:36 PM

The fact that it does this 'lunge' in every gear leads me to believe that it's not a transmission problem.

Can you describe the 'lunge' in more detail?

BTW, any engine modifications besides the dry clutch?

deftone · December 16, 2009, 06:41:56 AM

it has custom pipes made (straight with little baffling. similar to boom tubes) a power commander that corse superbikes mapped with the pipes(all this was done and working normal prior to this problem)....i re-routed the oil lines so they both go to the left side of the engine...that is it...it has an aftermarket slave for the clutch(also done a couple years ago)...when i changed the oil i put in spectro synthetic blend oil....not sure what it had before...

lunge description...
when taking off from a stopped position, as i release the clutch lever the plates grab and the bike starts moving forward as normal then once it approaches 2600rpm it feels like the bike wasn't completely in gear and drops in and revs go up to 3000...it then pulls like normal all the way up the revs...it is most noticeable in 1st because i rarely allow the revs to drop down that low in other gears....but in testing if i was in 2,3,or 4 i was cruising at speed....then i'd let off the gas and the bike would engine brake....i'd let it get down to about 2500rpm and give it gas and it would do the same thing....like it wasn't totally in gear until 3000rpm....one noted thing to add if i do not let the bike engine brake and pull the clutch in and use only brakes to stop it isn't as ubrupt but still there...

yotogi · December 17, 2009, 11:12:28 AM

I can't help but think that you are describing a surge that is common in the S2R1K. With your modifications it is possible that your map is off. If it happens even when not using the clutch, I am thinking it is not a clutch problem.

Not an expert at all, just thinking out loud.

deftone · December 17, 2009, 04:58:39 PM

Quote from: yotogi on December 17, 2009, 11:12:28 AM
I can't help but think that you are describing a surge that is common in the S2R1K. With your modifications it is possible that your map is off. If it happens even when not using the clutch, I am thinking it is not a clutch problem.

Not an expert at all, just thinking out loud.

i own an S2R1k and am aware of surging by poor mapping...this is not a surge problem....it is a clutch or transmission related problem...it doesn't surge, it falls in to gear or the clutch plates grab weird....

ducatiz · December 17, 2009, 06:05:16 PM

Quote from: deftone on December 17, 2009, 04:58:39 PM
i own an S2R1k and am aware of surging by poor mapping...this is not a surge problem....it is a clutch or transmission related problem...it doesn't surge, it falls in to gear or the clutch plates grab weird....

i would remove the clutch assembly and check it out on a work bench. manually push the plates, make sure the springs all move freely and compress.

check the slave. i wonder if somethign could be pushing BACK on the rod...

do you have any PCIII on it? check the map, that is a good bit.

double check the throttle bodies function, lube the cable. cable coule be sticking somewhere at the arc of turn that corresponds to your 3000 rpm observation -- R&R cable, but start with lube.

dunno, it's a weird problem, but my gut says it is something in teh control, i.e. ecu, throttle body, cable.

Speeddog · December 17, 2009, 06:25:07 PM

How worn are the basket, plates and hub?

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Unique transmission problem on custom S2R