G
DOES ANYBODY HAVE OR RIDE WITH SOMEBODY WITH THE 610 BB FOR THE 5OO KTM/HUSKYS
WOULD LIKE TO HEAR ANY FEED BACK ON THIS SETUP THX
WOULD LIKE TO HEAR ANY FEED BACK ON THIS SETUP THX
610 BIG BORE
- Thread starter Grape Taxi
- Start date
http://thumperracing.net/index.php?route=product/product&product_id=63
Haven't used one, but I'm sure you would need so e head work and a fuel controller to go along with it to take full advantage of the extra 100cc. Could be really cool if tuned right.
Haven't used one, but I'm sure you would need so e head work and a fuel controller to go along with it to take full advantage of the extra 100cc. Could be really cool if tuned right.
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G
Thx for the reply Mad Max, Brewster Motorsports in AB carry the 610 big bore, just wanted to hear about the life span,power differences vs the cost, currently run a dobeck, but will getting the head flowed regardless if i decide to go with bb. I put on 75 hr this winter and previous owner did 30, so i think its time to open it up anyway and have a look. Since its apart i was thinking about the bb but i also dont want to be getting towed home from the bush.
M
I didn't run the 610 big bore on my 450 but I did run the Thumper racing 520 so it uses the 450 crank vs the stroker crank. My motor ended up grenading when it took out the con which was a brand new KTM part when I first had the motor built. IMO the con rod is the weak link on these as another buddy took his out as well. I think the rpms put too much stress on the rod and the bigger piston doesn't help the situation. It's really going to come down to how hard you ride it as to how long it will last, each guys experience seems to be different.
All said Travis at Thumper treated me well on the second rebuild and sold me a bunch of parts at cost and ate some of the labor but it was still expensive and I wouldn't do it again I'd just stay stock. I do like the 520 on the dirt though you never need to rev it as it has gobs of roll on power.
M5
All said Travis at Thumper treated me well on the second rebuild and sold me a bunch of parts at cost and ate some of the labor but it was still expensive and I wouldn't do it again I'd just stay stock. I do like the 520 on the dirt though you never need to rev it as it has gobs of roll on power.
M5
C
570 thumper
I have a 570 Thumper kit in my KTM 450, however, I selected the RFS engine as it already has a long 72mm stroke. I have been absolutely impressed with this engine, great torque with smooth power. Did a stage three cam with 12.5 to 1 piston. Starts and runs flawless, couldn't be happier. The RFS engine is highly regarded for doing these mods, not sure on the newer 500 engines, however, Corrie @ Brewster West would know, he builds a lot of big bores, as well as some strokers and turbos. If you just want more power on occasion, chat with him about the Boss Noss Nitrous kits that he developed.
Cheers
I have a 570 Thumper kit in my KTM 450, however, I selected the RFS engine as it already has a long 72mm stroke. I have been absolutely impressed with this engine, great torque with smooth power. Did a stage three cam with 12.5 to 1 piston. Starts and runs flawless, couldn't be happier. The RFS engine is highly regarded for doing these mods, not sure on the newer 500 engines, however, Corrie @ Brewster West would know, he builds a lot of big bores, as well as some strokers and turbos. If you just want more power on occasion, chat with him about the Boss Noss Nitrous kits that he developed.
Cheers
Have a few buddies that run them on set ups with Timbersleds. Was the choice in the past for us when we ran TS. However with the Yeti we like to run more mx type bikes because we love the fast revving bikes and in turn higher track speed. Since this kit is so much lighter and efficient we no longer need the torque.
Building some two smokers because of this. Can't wait to try one out!
Had a buddy who had one on dirt only... thing was a pain in the a$$. Always some kind of issue with it. Can't say this is the norm, just my experience.
M
If you are married to the 4 stroke then IMO stay stock, get a 450 MX bike and ride the crap out of it for a season, sell it off, go again but in the end my cheap a$$ CR500 built 20 years ago will dominate any of the 4 strokes I've ridden with excluding turbos where it can still hold its own. I wish I had never gone down the 4T BB road as it was a complete waste of time and money for snowbiking. I blew more $$ on that setup then I have into my CR500 2T which absolutely pounds the 520 plus it is way more fun to ride. Just sayin......
M5.
M5.
S
I have looked into the 570 and the 610 kits from thumber racing and in no situation is the 610 the way to go. (Modding the cases are needed, over heating and can't go back to a stock jug, So once you go 610 you cant go back)
with that said the ktm 500 motors (510cc) as you may know don't turn as many RPMs as the 450 and the rods are much stronger then the 450s so big boring a 500 is a better option for long term use over the KTM 450.
My build is coming together nicely. Here's my motor info.
2008 KTM 530 (510cc)
SXF 450 carb 41mm, 530 stock carb is a 39mm
High compression piston. 12.7 to 1 from 11.5 to 1 stock
2015 KTM 500 cam more lift and duration and better decompression.
And a FMF power bomb header pipe.
I was going to do the 570 but I will wait to see how it runs with this set up.
I feel right now there would be more to gain with updating my 15 track to a 16 track over the 60cc added to the motor for about the same price.
with that said the ktm 500 motors (510cc) as you may know don't turn as many RPMs as the 450 and the rods are much stronger then the 450s so big boring a 500 is a better option for long term use over the KTM 450.
My build is coming together nicely. Here's my motor info.
2008 KTM 530 (510cc)
SXF 450 carb 41mm, 530 stock carb is a 39mm
High compression piston. 12.7 to 1 from 11.5 to 1 stock
2015 KTM 500 cam more lift and duration and better decompression.
And a FMF power bomb header pipe.
I was going to do the 570 but I will wait to see how it runs with this set up.
I feel right now there would be more to gain with updating my 15 track to a 16 track over the 60cc added to the motor for about the same price.
G
Well there seems to be more cons then pros, head work, new throttle body and a stock rebuild, longevity works for me.
Thx for the replies
Thx for the replies
3
I've got one (with Dobeck fuel controller) and it's a very noticeable change from the 500. Hills that I used to lose momentum and have to shift down on I can now accelerate on. It will now out pull all the stock 450's (assuming same rider and set up). It WILL NOT out pull a KTM with the 520 kit, but it is a lot cheaper and easier to install than the 520. My only complaint is the vibrations, they go way up (think 300cc 2 stroke).
C
570 on my 03 525sx. Would love to go bigger, but I got all the power I want and then some. Building a 04 490 on my 450sx. See how this monster will turn out. Lol
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