Hi Kev

I ride a XT660Z with 3rd Stage airfilter,Powercomander V and Leo Vince Pipes. 14T Front and 45 Rear sprockets.

Question: Why is the XT limited to 7000 RPM and can that be changed? What would the effect be of say a 8000 RPM limit?

Regards

put simply,
Limit is to keep stresses within acceptable levels. Its a big bit of metal going up and down in there and is changing direction 14,000 times a minute at 7000 revs. Engines with multiple cylinders rev much faster because the weight of the piston is much lower for a given CC and they compensate for each other when they change direction. Generally, increasing revs on a big single won't do much other than help to send it to a scrap yard earlier than would otherwise be the case. Big singles are not supposed to rev fast.

Al.

Sorry, Just noticed this was addressed to Kev, apologies for sticking my nose in.
Al.

Don't wory, It's not in the 'Ask Kev' section, so it's fair game.

edit - then again, it's not realy about drive kits either.... I'll shif it somewhere more appropriate

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Sorry for not following correct posting protocol.

Ilkleyal, thanks for the reply you are more than welcome. I do understand the need for engine protection. I just seem to hit the limit very often in 1st and 2nd.

If you're getting through 1st and 2nd the gears too quickly and hitting the limiter maybe you should give some thought to raising the final drive ratio a bit?

The rev limiter is there to protect the motor, moving the rev limiter higher will put more stress on the motor & reduce it's life over the long term depending on how the bike is ridden. If you are running the standard XT660 camshaft it is of no use reving it past 7000 rpm as the peak power has long gone & is dropping off fast.

If you want to raise your rev limiter the info can be found here.

http://www.xt660.com/showthread.php?t=16248

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Mods that I have done to my XTX's

My 04 XTX
Stage 1 & 2 DNA filters / Kev fuel mod / snorkel mod / Drilled air box mod / Engine breather mod / Fork Spacer mod / 15w fork oil /
[
My 07 XTX
Raptor 700 cylinder 102mm / Modified Crank Case to take a 105mm Raptor Cylinder / 11:1 102mm JE Raptor piston / Stage 1 Raptor Hot Cam / Ported head / Colder Spark Plug / +2mm Throttle body / DNA stage 1 & 2 filters / Modified Air Box / Snorkel removed / Worry Brothers stage 2 filter cover / 6mm & 8mm Bolts Replaced with Titanium Bolts / Recovered seat in Black / O2 Eliminator /

My 09 XTX
59HP at the rear wheel / Stage 2 Raptor Hot Cam / DNA stage 3 Air Box / Carbon Can Exhausts / Modified Exhaust Link Pipes / PCIII With Custom Fuel Map / Wideband Commander O2 Data logger / LCD100 Dyno Jet display & fuel adjuster / 2500 OHM HT lead instead of a 10K OHM XT lead / Extra Coolant Cooler / Protaper Fat Bars / Tail Tidy With LED Tail Light / OKE Protection Knobs / LED indicators / AIS blocked / Modified rear sprocket rubbers / Rear Foot Pegs removed / 09 ECU With 02 Sensor Changed To A 06 ECU / Complete wiring harnes Changed from 09 to 04 / Home made LED resistor flasher / Hole drilled in the fuel tank filler neck to allow quicker filling / Modified Bar End Weights / Progressive front fork springs, 15W fork oil, forks lowered 25mm, used XTR rear links lowering the rear 20mm, rear spring one click stiffer / Changed front & rear guards from blue to black / 47T rear sprocket / Speedo Healer V4.0 / Kev throttle cam mod / Throttle grip mod / The new 2010 O2 sensor mod is out, works a treat, The new 2012 O2 Controller is out, PM me for details

Now ride a 2018 MT09SP ABS + TCS

My KTM 990 SMR Mod book. http://www.ktmsmt.com/viewtopic.php?f=13&t=4946

No problem at all, why not pop over to the Newbies Reception Lounge and introduce yourself ? You can also find some other usefull information.

Here -> http://www.xt660.com/forumdisplay.php?f=23

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Did the introduction about a year ago. I have not been very active on the forum.