450 thumper racing kit

[pumpkin033]

I am considering a 450 kit for my 400 MXC from thumper racing, anyone have any experience with this product? Any reviews, comments?

 

[Badgas]

I took a Dick Berleson riding class about 3 weeks ago. Gary Hazel, the owner of Thumper Racing, had a 450 there he was riding. They just got finished doing a Dirt Bike Mag test on their 450 kit and their YZF 280 or 290 kit. I didn't get a chance to ride it, but with gary riding it it ran like bat out of hell. He said it's not much less HP than a 520. Also he said likes it better because it's short stroke engine. Which makes the bike feel lighter. Less reciprocating (sp?) mass. KTM's new 450 is going to be a 450 long stroke. I don't know what month the mag test is going to be out. Give Gary a call. Super nice guy.

Gas
:cool:

 

[pumpkin033]

thanx gas, will do that.........

 

[rollingp]

I think Erick Gore is doing the 450 kit also.

 

[ktmwes]

Originally posted by pumpkin033
I am considering a 450 kit for my 400 MXC from thumper racing, anyone have any experience with this product? Any reviews, comments?

I installed a 454 Thumper kit about 4 weeks ago and after 3 rides I have to say it's sweet, this is what should have been. I decided on the 95mm kit to keep the 11:1 compression and I did mine the quick and dirty/expensive way by buying a 520 cyl which saved me approx 3 weeks of down time, as I understand it the bigest part of the wait is sending the cyl out for boring a replating. The engine is easy but not quick to work on and if your not comfortable working on your engine the price they quoted seemed very reasonable. Anyway the difference in riding is very pronounced with the biggest gain in the low to mid range torque and it allmost seems to have a midrange hit now and keeping the front end up or light is now easy. Last weekend I rode my bike back to back with a 300 MX/C and a 520 MX/C and the 450 is close enough to the 520 now and at least on par with the 300
the engine revs quicker than a 520 but not as quick as a CRF 450. On the downside I seem to Kill the engine while riding 1or 2 times more than I used to or about the same as me riding a 520 (who knows, just an observation) rear tire wear is going to be more of a concern. The bike has 14/52 gearing, PC T-4 exhaust with 2" outlet and stock jetting. Future projects are a 520 cam and jetting refinements, power to be had in both I'm sure but I'm really happy with the overall package right now. You will like it!

Wes

 

[T Genet]

I don't know anything about Thumper Racing other than 3rd party info. But you may want to check out the march issue of Dirt Bike. The Super Bike shop is having their 2nd bike in their within the past year. He had the 540 KTM in their this summer. The one in March or April will be a 450 KTM. He does awesome work, does his own machine work. He will have a rider running the outdoor nationals on his 540 this year.

 

[scottyr]

Cycle Improvements in Kitchener, ON, Canada is doing a real nice 450 kit also. I have heard a lot of good things about it and James Hunt of CI really knows his stuff. And remember, you USA dollar goes a lot further up in Canada.