Thumper Racing 306 riding impressions

I've got three real rides on my 306 now & I'm very impressed/pleased with the package. The power gains from the 23% displacement increase & head porting are much more than the numbers would suggest.
It's as smooth as stock with more power from top to bottom. I've ridden two track, deep sand & some really gnarly, rocky as you can imagine single track from 1000' to over 8000' elevation.
Riding tight single track well into the 90's  bike has zero cooling issues (I on the other hand was overheating)
The vastly improved low end means less downshifting, it'll pull a gear higher everywhere. The engine pulls sixth so much easier I find myself trying to shift to 7th. I may rethink my 14/49 gearing.

Stop giving me ideas....

Good to hear you're enjoying the upgrade. How much has it set you back, and what was involved? (did you do the work or did you send it out?)

I bought the R2 planning to install a Thumper 280 kit. A member here had bought the 306 kit & never installed it. He sold it to me very reasonably. I bought a complete spare engine, again very reasonably & built a complete engine leaving my 4880 mi original engine intact wrapped in plastic on the shelf. I did all of the assembly, pretty simple engine to work on. I bought a flywheel puller & improvised puller/pusher tools to press the crank in & out of the bearings using pipe/scrap.  All together I have $1200.00 in the engine.

What is the projected reliability/maintenance?

Is this going to be just as maintenance-free as the stocker?

ac

For my use I expect stock or near stock reliability. It's built with the same cylinder coating type with a 3 ring piston like stock. The only thing that is not quite as good as stock is the rod stroke ratio. The rod is 1.5mm (~1/16") shorter than stock to compensate for the 3mm longer stroke. Now, if I was running WFO all the time I'm sure the additional power would shorten the life of something.

I did a very spirited 85 miles today & really enjoyed the newfound torque. Powering out of turns without having to downshift every time is just fun, carrying the front over rain ruts & whoops is easy.
I keep looking for 7th gear it pulls 6th so much easier than before. I'm running 14/49 & think 14/47 might be the ticket & I can just swap in a 13 for serious single track.

Sounds pretty sweet....can I ride it?

sure

One of the things I was curious about with the displacement increase was the capacity of the cooling system. I live just outside of Phoenix & it's just past the middle of July & I am now certain the bike can handle the heat better than I can. My fan doesn't seem to run anymore than any of the 450's I ride with.

Cool !!! (pun intended  )

Did you look into the ktm dualsports before going all out on the little yamaha?

beee wrote:

Did you look into the ktm dualsports before going all out on the little yamaha?

See my avatar? that was a 2007 KTM450XC & I have had others. It was a great off road bike, lots of power, handled well & it weighed 300lbs like you see it in the picture.

 I originally bought the WRR to replace a larger adventure bike for the rides that had some pavement. After some shakedown runs getting ready for a Death Valley trip I realized I never once on those rides was I wishing I was on the KTM. I have less than $1200 in the complete engine that is in the bike, the original engine is untouched & wrapped up under the work bench.

  I rarely need to do anything the WRR when I get back from a ride except wash it. The KTM required a bit more love, not horrible, but more.

 It doesn't make me feel guilty buzzing down the hwy like the KTM did, the WRR is much smoother & after the same ride on the R2, I am much less tired  Although the bikes weigh the same ready to ride the WRR feels much lighter. Fuel range, with a 3.4 gallon tank on the KTM & a 3.1 gallon tank on the WRR the WRR is the easy winner.
 

 The newer KTM250 & 350's are very nice bikes & for extremely tight single track would be easier to ride. For everything else the R2 is just as good & better.