The KTM300 Thread

Most problems are do to operator error and modifications

Nickelmine riding area in Hope, B.C.

Endless trails, from flowing singletrack to "OMG is that even rideable?"

Fun times with The Punisher and some fast feckerzzz

Rode a buddy's tx300 with MX-Tech enhanced Aer forks and revalved shock. Absolute love

Makes me think that an XC will be in my future

I was honestly worried when I added a 300 to the collection. I hade done it all on my 500 so really needed some versatility in a moto.
I'm not just a single track snob. But when I go out west for the summer I run it all. Passes, ATV trails, Jeep roads and obviously my true love the skinny gnar.
I was pleased to discover that the new TPI machine did just fine in all those conditions. Here's a look at a run up a high mountain Colorado pass that included some massive rock sections.

Your riding budz look like a ton of fun. And I already like Canadians. And your trails are steeper too. Keep posting those great photos for those who don’t have anything like it nearby.

Thanks for sharing your video. I really enjoyed the climb from my armchair drinking strong coffee. It ‘s worth noting that the TPI system worked flawlessly constantly adjusting for changes in altitude. The motor sounded great. It’s a different story with carb bikes, although the Lectron seems to manage better than other carbs. I have appreciated the mpg increase seen with TPI also when dual sporting. I could consistently get 80 miles out of a stock fuel tank, on one occasion almost 90 when ridden carefully for maximum distance. 60-70 was what a carb would deliver, and worse when going up 5000’ in elevation. And you look nothing like your thumbnail.

Any one run a throttle tamer? If so recommendations?
I have had this bike fly out from under me on a few double log crossing. I think I could benefit from slower initial opening.

“ I looked back and greasy’s bike was coming at me skid plate first” quote from a rider in front of me.

Have one. It helps with precise throttle control in the gnar. That and the gray wire switch really mellow it out. Also, it's a better quality piece than the stock throttle tube

This is a case where adjusting (or maladjusting) the power valve might actually make sense.

With a reasonable choice of settings, you will just make the power hit later, but harder. That might be what you want - just never pin it.

Or, with a weak enough spring, you will never fully open the powervalve, effectively neutering the bike.

What one are you using?

G2 with the "grandpa" throttle cam

“Quick” throttles are usually not the problem. It’s usually a slow reaction with the clutch that makes it seem like a throttle problem.
I go through this all the time with some trials riders. They want the slow (black) Domino tube when their bike comes with the faster (white) tube. The slow tubes, or cams make you twist your wrist down into an un-natural weird position when trying to give it max throttle.
IMO and YRMV you need a standard or even a quick throttle and a quick clutch finger.
If you slow the throttle down, you are just fooling yourself and will then not be able to open the throttle all the way and have your arm in good position at the same time.

My new TRS trials bike even came with a modified white tube to make it quicker. They glued a wedge onto the cam and I love it!



I would not go this extreme on the KTM but could see getting a smoother acting bearing throttle.

100% this. At least in my experience.
The clutch is so much faster and more precise than the throttle for modulating power to the rear tire. It'll save you from loop-outs far better than trying to chop the throttle and waiting for the engine to spool down (takes time for all that reciprocating/rotating mass to slow - clutch is instant).

I do find modulating the clutch more than the throttle to be a big help as well.

Rich larsen (irc tire guy on yt) talks about it a lot. Clutch control is a main skill.

I went to a quick turn throttle when I broke my right wrist a year and a half ago. It kept me riding (along with liberal amounts of hockey tape and ibuprofen) which was nice. However, I went back to the throttle tamer once I was all better.

Clutch is definitely the best way to modulate traction, and prevent loopouts, but in the gnarly crap it's smoother for me to have precise throttle control too. It's not game changing one way or the other, but on balance I like it where I ride. And most of our local trails are ridden using well under half throttle

You're bass-ackwards.
The red spring is the soft spring, the green spring is the stiff spring, the yellow spring is in-between.

You run the red spring to get the powervalve opened ASAP, you get more power sooner.
You run the green spring if you think that a 1979 RM125 had the perfect powerband (it opens the powervalve later)
All they do is change when the powervalve is fully open.

The powervalve starts to open at 5600 RPM
With the red spring it's fully open at 7,200 RPM, with the yellow spring it's fully open at 7,900 RPM and with the green spring it's fully open at 8,400 RPM.
By turning the carriage screw you can start opening the powervalve 150 RPM's sooner with each full turn OUT or 150 RPM's later with each full turn IN.

No matter the color of the spring or how many turns in or out of the carriage screw, when the powervalve is fully open it's going to make the same torque and HP.

I see, so the spring resists rather than forcing the opening.

However, if you look at the dyno I posted, it does not make the same peak HP or torque regardless in JD's testing. It appears the valve is never fully opening.

Lots of 300’s racing today at Walker Valley. Note the twin horns on #375 above. Blast to pass!

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Look at the dyno-chart again.
First off it's a torque chart and not a HP chart.
Second, when did I say the powervalve is fully opened for the green spring?
8,400 RPM
Look at the chart at about 8,400 RPM.
All of the torque lines are merging at about 8,600-8,700 RPM's.
That's when the powervalve is fully open no matter what spring you are using.
Of course the torque readings will be different for the different springs, the powervalve is not fully opened until 8,400 RPM's.

This is the chart that shows when the powervalve is opening.


I don't like the green spring because it kills the power until the powervalve fully opens.
Because the engine is running at a higher RPM you get that old school "powerband" hit...BaaaaaaWWWWWAAAAAAAAAA.

There's a lot more involved with the springs than just the colored springs.
There's the carriage spring adjustment.
There's the wheelie wire / map switch.
If you're running a stock, Gnarly or Fatty (or some other) pipe.
Do you have a high compression head?
Are you running an aftermarket ECU?
Did you ditch the FI for a Lectron or other aftermarket carb?
Did you change the injector location?
Even the throttle cam comes into play.
Is your bike a carbed model?

Was it wet everywhere or was it dry under the trees?
That's the way I like Walker.

I think the green spring is the hardest to ride for excactly the reason you typed. For me the red spring is the smoothest.