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Discussion Starter · #1 ·
background/pertinent info:
bike - 2005 Yamaha R6 30k miles
engine/trans/clutch is stock
vortex rearsets gp shift
vortex 520 -1, +2

i've been having some transmission troubles out of the bike lately and would like some input from those more familiar with these machines.

the past three track days at putnam, the bike has been jumping out of gear occasionally. the straight shoot between turns seven and eight, shift from second to third, pin the throttle and it will jump back into second (i shift slightly early (14k rpms) out of second to get a good drive out of turn eight). it does this maybe twice in a 20 minute session. also exiting turn 10 shifting from second to third (this time at about 14.5k rpms) it will fail to shift about four times a session.

until today, i've only had issues on the track.

as of today's 300 mile street ride - full throttle fifth gear over taking a car. shifting at roughly 13k rpms into sixth i got a 'false neutral.' engine free revved to the limiter. kicked the shifter down again and it went right into sixth gear. i was maybe 130 miles into the ride when this happened. it was fine for the remaining 150 miles or so. also, as a reference, i did about 250 miles yesterday without an issue.

also, each of these events has occurred during clutchless shifting. however, i rarely use the clutch when up shifting, even when commuting.

any experiences with this type of issue?
 

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background/pertinent info:
bike - 2005 Yamaha R6 30k miles
engine/trans/clutch is stock
vortex rearsets gp shift
vortex 520 -1, +2

i've been having some transmission troubles out of the bike lately and would like some input from those more familiar with these machines.

the past three track days at putnam, the bike has been jumping out of gear occasionally. the straight shoot between turns seven and eight, shift from second to third, pin the throttle and it will jump back into second (i shift slightly early (14k rpms) out of second to get a good drive out of turn eight). it does this maybe twice in a 20 minute session. also exiting turn 10 shifting from second to third (this time at about 14.5k rpms) it will fail to shift about four times a session.

until today, i've only had issues on the track.

as of today's 300 mile street ride - full throttle fifth gear over taking a car. shifting at roughly 13k rpms into sixth i got a 'false neutral.' engine free revved to the limiter. kicked the shifter down again and it went right into sixth gear. i was maybe 130 miles into the ride when this happened. it was fine for the remaining 150 miles or so. also, as a reference, i did about 250 miles yesterday without an issue.

also, each of these events has occurred during clutchless shifting. however, i rarely use the clutch when up shifting, even when commuting.

any experiences with this type of issue?
I got a false neutral only 1 time in the 7k miles I've ridden on my bike and it was during a botched up clutchless upshift.

I shift with the clutch at all times, unless I am riding one-handed. I'd suggest shifting with the clutch, but to each their own tho.
 

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Discussion Starter · #3 ·
I got a false neutral only 1 time in the 7k miles I've ridden on my bike and it was during a botched up clutchless upshift.

I shift with the clutch at all times, unless I am riding one-handed. I'd suggest shifting with the clutch, but to each their own tho.
no offense, but i'm not looking for advice on how to operate the machine. i am looking for insight on common failures during high performance/race use of the factory transmission assembly. i.e. shift fork wear, gears rounding off, or bearing fatigue that could possibly lead to the issue i have described.
 

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no offense, but i'm not looking for advice on how to operate the machine. i am looking for insight on common failures during high performance/race use of the factory transmission assembly. i.e. shift fork wear, gears rounding off, or bearing fatigue that could possibly lead to the issue i have described.
True. No offense taken. Maybe include some cliff notes in the OP so someone other than me will read your novel.
 

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well im no motorcycle tech or mechanic .. but i do all my own work on cars+bikes.

Sounds like your clutch is just slipping, and with 30k and mostly clutchess shifting, track running, it just sounds to me like your stock clutch finnaly wore out.
it really is not too difficult to just take a look at your clutch plates and see their condition.
doesnt sound like anything more than that to me.
 

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Discussion Starter · #6 ·
True. No offense taken. Maybe include some cliff notes in the OP so someone other than me will read your novel.
glad you didn't take that the wrong way! the type of person who i'd like to speak to will probably need even more details than what i've listed. but this should get the ball rolling. i'm an ase certified master tech, it's nice to have as many details as possible when diagnosing something without being able to reproduce it in the shop.

well im no motorcycle tech or mechanic .. but i do all my own work on cars+bikes.

Sounds like your clutch is just slipping, and with 30k and mostly clutchess shifting, track running, it just sounds to me like your stock clutch finnaly wore out.
it really is not too difficult to just take a look at your clutch plates and see their condition.
doesnt sound like anything more than that to me.
clutch fibers are about 3k miles old (replaced on sept 19th 2010 - i keep notes ;) ). steels were checked the day i brought the bike home and every time i change the oil (roughly once a month). no hot spots, no warping, and spring tension is even. clutch slip would not cause a false neutral or a pop out. potentially the main shaft (for lack of a better word) bearing could cause the shaft to flex enough to force a missed shift, but that would be accompanied by a vibration or noise. i am not experiencing any abnormal noises or vibrations at race pace or putting around on the street. i am 110% sure the clutch is not slipping. the bike has been on the dyno four times this week. the pulls are as clean as day 1.

thank you for the insight and opinions. anyone else care to chime in?
 

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Sounds like a bent or worn shift fork and/or worn slots on the fears. If it's dropping down a gear it sounds like you aren't gettingthe gear over far enough to stay in gear. I suspect you're going to be replacing the gears and forks though.
 

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Youve finally Rounded the edges of your gears from all of your johnny knee dragger clutchless shifts. Once you split your cases you will see most of your gears are oval in nature. replace. and start using your clutch, thats why its there. lol
 

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Discussion Starter · #9 ·
Sounds like a bent or worn shift fork and/or worn slots on the fears. If it's dropping down a gear it sounds like you aren't gettingthe gear over far enough to stay in gear. I suspect you're going to be replacing the gears and forks though.
i'm leaning heavily towards a tweaked shift fork. or possibly a groove/burr on one of the paws. seems logical as it only happens under extreme loads. shifting is always seamless below 12k rpms.

i have a low mileage motor for parts. may steel the trans assembly out of it and have it cryo treated if there is indeed excess wear on any of the gears or forks.

thank you for the replies.
 

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Youve finally Rounded the edges of your gears from all of your johnny knee dragger clutchless shifts. Once you split your cases you will see most of your gears are oval in nature. replace. and start using your clutch, thats why its there. lol
clutchless shifting doesn't hurt the transmission when done right.
mine has 40,800 miles and I've been clutchless shifting it for the most part. most racers never use it. they use a quick shifter which kills the power for a split second when you hit the shifter. using the clutch takes a lot of time away from accelerating.
I promis you my shifts are faster and smoother without the clutch than yours is with it.
it's called a sequential transmission. it's intended design is so you can shift without using the clutch. in fact, you only need it to stop. you can down shift one also.
http://en.wikipedia.org/wiki/Sequential_manual_transmission

hard to say what it is without looking inside. but the 2nd and 3rd gen have pretty stout transmissions. you wont find too many people with a problem out of it.
 
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