My completed xr300 project!

I wanted to show the results of a couple month long project to build the ultimate bike to suit my needs.

I ride woods trails here in new england, alot of tight singletrack, slick roots and rocks and the occasional fire road/powerlines. I like modern liquid cooled woods bikes, like the CRF-X but wanted something that would last longer between rebuild, not have exposed radiators and be less expensive. I have always liked the XR250 but, like everyone else, thought the power and front suspension was lacking a bit.

To start the build I took the bike apart, had the frame done with two part epoxy paint and reassembled from there.

300cc thumper racing kit, wiesco forged piston,34mm upgraded carb, ported and polished head, valves, springs etc.

EVERY bearing in the engine replaced, transmission/crank/counterbalancer/cam. Every seal and gasket, HD clutch kit. Pro Curcuit T4 exhaust with Titanium coating (like jet-hot). I was very detailed in the reassembly, every copper washer and o-ring for the oil lines are new.

Swingarm and shock bearings new, front and rear wheel bearings/brakes, sprockets and chain, tires and tubes.

Summer racing fork brace, applied racing triple clamp, oversized bars, summer racing clamp mounted hand guards.

The bike feels 100% better than before- compared to stock the power is amazing! Pulls harder everywhere, and is so much more crisp. I am a big believer in the TM34 carb. The tripple clamp and fork brace did wonders for the front end, as did the oversized bars. No more deflection or wander when hitting rocks/roots.

Next step is to redo the plastics, when I bought the bike it had the carbon fiber applied to all surfaces, and make a baffle for the exhaust. It sounds great right now, but I don't want to upset the neighbors.

The finished bike


Closeup on the engine


The rear caliper guard was painted frame color



Rest of the pictures..





Why are you selling it then?


Why are you selling it then?


Change of job

how much ?

NICE I love the black accents,shifter,skid bars, ect.

Job or no job, I'd hang on to that bike !:thumbsup:

That bike looks GREAT!!

Bike is for sale, $1600.

Email me, mhaskell at

The bike looks great. How is that Carbon fiber holding up on the tank? I have an extra tank and might give that a try.


Wow, you did a great job on that bike. It looks fantastic.

Plate it and sell it for $2600. Just saying...

Plate it and sell it for $2600. Just saying...

The paperwork is already in process for plates. Still needs a DS kit to be registered in mass.

What did you use for fork wipers? I really like the look of forks w/o boots. A great build!

The paperwork is already in process for plates. Still needs a DS kit to be registered in mass.

If I had the cash and was able to pick it up I would buy it for the $2600, plated worth it. My dream, if it would work, is doing the 300 TR to mine, maybe see if the Powroll stroker crank would work with it and figure out how to get a 400 oil cooler. Unfortunately my motor is the L motor so I would have to drill or find an R right side.

Tried searching for summer racing, do they have a website?

Tried searching for summer racing, do they have a website?

Summer or Thumper?

I really like black XRs! Where'd you get the rear fender?

I've got the same engine kit as you (plus HotRod and Megacycle moderate cam) with a VM34 from Sudco but mine cuts out at high revs. What jet sizes and needle settings did you end up with?

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