990 sm shifting problems

JR_FX · 10-28-2012, 02:24 PM

I have a friend with a 990 SM that is complaining about the 2 gear "jumping"occasionally when he opens up the throttle or feathers the clutch to pop up whellies. Apparently, when he´s cruising everything is normal.

What do you guys think? I´m leaning towards the gear shifting mechanism - coul be the drum with a broken wall between the tracks, or the rollers...

Either way we are looking at spliting the cases, right?

geometrician · 10-28-2012, 05:46 PM

no you don't have to split the cases to deal with the shift mechanism

when I am bouncing up REALLY hard-rock trails & stair steps I've had my 950AdvS jump out of gear when in 1st or 2nd into neutral- I've been riding for a long time & I know it's not my boot doing it

I think (and have thought of starting a thread on it) that the shift-detent spring that keeps the detent roller pressing into the shift-drum gear-detent-cam is weak.

Many bikes have had their shift detent springs strengthened by aftermarket companies like Factory-Wheelsmith Racing to keep the bike in (whatever) gear under accel/deceleration

I've wondered if anyone (including the KTM Factory) ever produced stronger springs for this... it's annoying to be working a steep trail only to have the bike pop into neutral...

crashmaster · 10-29-2012, 09:59 AM

Quote:

Originally Posted by geometrician

it's annoying to be working a steep trail only to have the bike pop into neutral...

BTDT.

JR_FX · 02-14-2013, 03:07 PM

A litle update - we opened the clucth cover and the gear shifting mechanism was all good. while at it we cleaned the clutch oil jet - it was cloged.
The gear change got better, smoother, but the 2nd gear still pops out ocasionally.
I´m thinking that the problem migth be a damaged shifting roller.
Will split the cases in a nearby future.
My questions now are:
- what special tools do I really need do open up (and close

) the engine?
- besides the shifting roller(s) and the gasket set, what parts do I need (or should) order - we´re trying to minimize the inop time for the bike as it is his daily commuter?

10-28-2012, 02:24 PM	#1
JR_FX ^OP Adventurer Joined: Dec 2007 Location: Funchal, Portugal Oddometer: 94	990 sm shifting problems I have a friend with a 990 SM that is complaining about the 2 gear "jumping"occasionally when he opens up the throttle or feathers the clutch to pop up whellies. Apparently, when he´s cruising everything is normal. What do you guys think? I´m leaning towards the gear shifting mechanism - coul be the drum with a broken wall between the tracks, or the rollers... Either way we are looking at spliting the cases, right?

10-28-2012, 05:46 PM	#2
geometrician let's keep going... Joined: May 2008 Location: West-By-God Virginia Oddometer: 987	damnit no you don't have to split the cases to deal with the shift mechanism when I am bouncing up REALLY hard-rock trails & stair steps I've had my 950AdvS jump out of gear when in 1st or 2nd into neutral- I've been riding for a long time & I know it's not my boot doing it I think (and have thought of starting a thread on it) that the shift-detent spring that keeps the detent roller pressing into the shift-drum gear-detent-cam is weak. Many bikes have had their shift detent springs strengthened by aftermarket companies like Factory-Wheelsmith Racing to keep the bike in (whatever) gear under accel/deceleration I've wondered if anyone (including the KTM Factory) ever produced stronger springs for this... it's annoying to be working a steep trail only to have the bike pop into neutral... __________________ Britt '06 KTM 950 Adv 'S' '03 KTM 250 EXC '88 KLR650 - +170K miles "looks like you've had a lot of fun on that bike..."

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02-14-2013, 03:07 PM	#4
JR_FX ^OP Adventurer Joined: Dec 2007 Location: Funchal, Portugal Oddometer: 94	A litle update - we opened the clucth cover and the gear shifting mechanism was all good. while at it we cleaned the clutch oil jet - it was cloged. The gear change got better, smoother, but the 2nd gear still pops out ocasionally. I´m thinking that the problem migth be a damaged shifting roller. Will split the cases in a nearby future. My questions now are: - what special tools do I really need do open up (and close ) the engine? - besides the shifting roller(s) and the gasket set, what parts do I need (or should) order - we´re trying to minimize the inop time for the bike as it is his daily commuter?