Thumper Racing 610cc 2008 KTM EXC

KiwiBird

LIFETIME SPONSOR
Jan 30, 2000
2,385
0
Well, the 610cc kit is a real eye opener.

I've been hounding Travis at Thumper Racing for a big bore for the 530 since I got it. The Christini has so much traction that the stock, uncorked and jetted 530 would not spin up very quickly. My '04 525 with the Thumper 570 kit with a bunch of other stuff spanks the stock '08 530 so I wanted a 570 for the new scooter.

Finally got the call and Travis says "570? Or bigger, maybe over 600? What do you want?"

I delivered my bike and, after the work was done and it was jetted, I got to ride it this weekend.

My only mistake was not having a new tire - I was using a Maxxis IT, which is a good tire when new, and lasts all summer, but was all used up.

100cc more is 20%. If my bike made 50hp it makes 60hp now, my butt dyno agrees. The torque is night and day difference. This is why I sooooooooo needed a new tire. I could light both tires in 3rd gear pretty much anytime I twisted it hard. Spinning both tires HARD on the Christini is very hard to control.

Jawbone has a hill called "The Wall" or "Widowmaker" with a steep, wide hill I've been up a million times, so I can judge how strong a bike is. Without the motor work my Christini goes up that hill faster (in 3rd gear) than most bikes. It now pulls 4th, remains to be seen if a new tire will help or hurt.

On open trails the bike is huge fun, roll on in 3rd and 4th is so strong it took until Wednesday for my arms and back to recover.

The bike starts the same on the button, don't notice any vibration, it sounds better.
 

muddymoto

Member
Dec 4, 2009
4
0
KiwiBird said:
Well, the 610cc kit is a real eye opener.

I've been hounding Travis at Thumper Racing for a big bore for the 530 since I got it. The Christini has so much traction that the stock, uncorked and jetted 530 would not spin up very quickly. My '04 525 with the Thumper 570 kit with a bunch of other stuff spanks the stock '08 530 so I wanted a 570 for the new scooter.

Finally got the call and Travis says "570? Or bigger, maybe over 600? What do you want?"

I delivered my bike and, after the work was done and it was jetted, I got to ride it this weekend.

My only mistake was not having a new tire - I was using a Maxxis IT, which is a good tire when new, and lasts all summer, but was all used up.

100cc more is 20%. If my bike made 50hp it makes 60hp now, my butt dyno agrees. The torque is night and day difference. This is why I sooooooooo needed a new tire. I could light both tires in 3rd gear pretty much anytime I twisted it hard. Spinning both tires HARD on the Christini is very hard to control.

Jawbone has a hill called "The Wall" or "Widowmaker" with a steep, wide hill I've been up a million times, so I can judge how strong a bike is. Without the motor work my Christini goes up that hill faster (in 3rd gear) than most bikes. It now pulls 4th, remains to be seen if a new tire will help or hurt.

On open trails the bike is huge fun, roll on in 3rd and 4th is so strong it took until Wednesday for my arms and back to recover.

The bike starts the same on the button, don't notice any vibration, it sounds better.

HI KIWIBIRD
i see you have done a conversion to the 530 i am too looking for the most i can get out of the bike and me,
whats it like living with the 610 conversion is it more maintainance on the engine
mainly is the spend well worth the horsepower gain as im looking to get the head polished and ported and a akroporvic, im using it as a supermoto and i just want to wipe the smiles from some faces when i rock up against some sports bikes.
your help and info would be gratefully received
Regards

Ian from the uk
 

KiwiBird

LIFETIME SPONSOR
Jan 30, 2000
2,385
0
Hi muddy,

I run a 41.5 mm carb, Akro muffler and Vortex ignition. The head is mildly ported. Thumper Racing is working on a cam (you'll want that).

The 610 is great. I've had it for about a year now. Decreased oil and filter change intervals are the only change in maintenance.

No major problems but the starter needed a bit of help once the motor was run in so we modified the starting electrics (PM me for details). You will need a bigger water pump (Mino or KTM) as it does generate more heat - I run a fan and a recovery tank in case the fan fails.
 

muddymoto

Member
Dec 4, 2009
4
0
KiwiBird said:
Hi muddy,

I run a 41.5 mm carb, Akro muffler and Vortex ignition. The head is mildly ported. Thumper Racing is working on a cam (you'll want that).

The 610 is great. I've had it for about a year now. Decreased oil and filter change intervals are the only change in maintenance.

No major problems but the starter needed a bit of help once the motor was run in so we modified the starting electrics (PM me for details). You will need a bigger water pump (Mino or KTM) as it does generate more heat - I run a fan and a recovery tank in case the fan fails.

Thank you for the info
was the spend on the engine well worth the smile factor it causes compared to the power the stock motor pumps out as its a lot of cash to spash out on something thats not really going to impress that much

or has it completely turned it into a snarling animal that likes to chew rear tyres for a hobby :)

Your input is gratetfully recieved

Regards

Ian
 

KiwiBird

LIFETIME SPONSOR
Jan 30, 2000
2,385
0
Loads more power, much broader powerband, 4th gear wheelies instead of 3rd, waaaaay more rollon power at higher speeds.

Big smiles. :aj:
 

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