View Full Version : TTR 600 info

Bush Chook
15-12-2003, 11:32 PM
Hey Gang,

I have recently bought a 98 TTR 600 and for one am having problems finding any information concerning tests, mods, problems etc......can't even get a workshop manual. Any url's or other info would be much appreciated.

It has 5000k's (mainly road use) and was entirely stock when I got it. Since then I have cut and shut the exhaust down to 300mm, pissed off the airbox snorkel and drilled 3 12mm holes in the airbox, ripped off all the crap stickers, checked for any restrictors and basically done a full service and setup.
It has always had a flatspot in the midrange, its torquey off the bottom and the top end is also quite punchy (revs out pretty quick though). The midrange flatspot has gotten progressively further ironed out since the exhaust/airbox mods and even re-oiling the filter (it was a bit saturated) but its still there (makes monos a bit trickier).
A bike mechanic I trust says the carbs are notoriously hard to setup on TTR's because of access aswell as the YDIS (vacuum secondary) setup. He mentioned raising the main needle a notch and possibly fiddling with the YDIS port opening setting to get rid of the midrange flatspot.
As I know they can be a prick to start even when the idle adjustment is a bit out I was looking for a few second opinions and any experience concerning this task before I need to inject steroids into my right leg for an arvo of kickstarting.

Any info would be much appreciated Thanks Bush Chook

16-12-2003, 10:06 AM
Check out this link for TTR600 info. Lots of info and links to other TTR600 sites.


Here's a good post thats on another aussie dirtbike site as well.



Bush Chook
16-12-2003, 11:41 AM
Thanks Paul,

Heaps of good info on both of those threads, looks like I'm gonna have to get some road wheels as everyone motard's the TTR's, nah I like throwing roost to much.

Thanks again Bush Chook

20-12-2003, 07:18 AM
There's an electronic de-restriction to do on them as well. I can't remember the exact details, I got them from my dealer, but you disconect a connector under the seat near the black box, and advance the secondary carb (but I can't remember how much by) 2mm rings a bell.


Bush Chook
20-12-2003, 10:26 AM
Thanks Charlie, this is starting to sound promising, I gather advancing the secondary carb 2mm is so it opens earlier in the rev range?
None of the Yamy dealers around here have told me of the electronic restriction, if anyone has a wiring diag, pic or further info on this I'm keen to give it a go. Bush Chook

21-12-2003, 07:17 PM
I was never clear on what they meant by advancing by 2mm.
I assumed the same as you, but never worked out where to measure it. My dealer just said we've done this for you on the service.

From memory it's fairly obvious which wire to disconnect when you look under the seat.


Bush Chook
21-12-2003, 08:20 PM
Yeah I think I know which wire it is, looks a bit like an inline fuse connector.
I've found a bit more info that seems to suggest that wire is simply to the rev limiter which is a bit strange because wouldn't the thing valve bounce before you could feel any limit in the revs?

The bike is up at the farm now so I'll have a bit of a fiddle over christmas and report back.
Thanks again Bush Chook

PS. also having a bit of a prob with the rebound on the Ohlins shock, doesn't return to full travel readily and the rebound requires a set of Vicegrips to adjust. I've been told a few things so I'm just trying to weigh up my options.

02-03-2004, 10:57 PM
hi bush chock.
i have a 98 ttr600 belgada,
i cut all internal baffles out of the exhaust,
removed the snorkle, adjusted the 2nd carb, to open at a little less than 1/4 throtle, lowered the needle clip 1 noch on 2nd carb
spark plug colour is spot on light brown, this solved the mid range problem, gave a lot more bottom mid range torque!
there is a black wire with a red trace coming from the cdi unit,
this i beleive to be a ignition retarding rev limiter!
the trick to getting more power seems to be in the compressoin
ratio, std is 8.5 to 1!
wisco sells a piston that will raise it to 10-1.
i was told that the xt660 piston with a new sleeve will be a great mod, they share the same stroke!
england even gets a elctric start as well on there new ttr600.
i have changed the gearing to 14/ 48
found it to be better in the bush and still goes to 150 on the freeway.
happy to share info, bobnegger@bigpond.com