ATV Action Magazine Review of Thumper Racing Raptor 280 Quad

Yamaha’s Raptor 250 is one of those rare quads that does everything right. Its only real shortcoming is that it’s a 250, so anyone who’s power hungry, or on the large side for a 250, will need more juice from the engine. Thumper Racing has been developing durable, reliable, thoroughly tested performance kits for popular ATVs for years. When we heard they had a project Raptor built around their new 280cc engine kit, we couldn’t wait to wring it out.

What’s in the kit?

Everything that’s needed to give the Raptor more bite. The basic 280 kit includes the piston, cylinder sleeve, jetting kit and gasket kit. Our project machine was more serious, with a cam valve spring kit and head porting. An FMF pipe completed the engine mods. The details on the project from the guys who built it We sat down with Thumper Racing’s Travis Smith and Jesse Alexander to see what they had in mind when they put together the Raptor 280 project quad

ATV Action:

What were your goals for the engine kit?

Thumper Racing:

We wanted to make the Yamaha more responsive and make it pull harder throughout the power band. The 250 has good bottom end snap, so we concentrated on giving it more mid to top power.

ATV Action:

How long has the kit been around? Is ATV Action the first to test it?

Thumper Racing:

This is the first test of the kit outside our internal testing.

ATV Action:

Does the engine require race gas?

Thumper Racing:

No. Premium pump gas is fine.

ATV Action:

Is the Raptor 250 engine hard to work on?

Thumper Racing:

No. Installing our kit in the 250 should be very easy for any good home mechanic. Pay attention to the timing marks so you don’t confuse them and you’ll do fine.

ATV Action:

Can customer send you their engines and have you install the kit?

Thumper Racing:

Yes. Many customers send us their engines. You can drop your whole quad off or ship it to us if that’s what you prefer.

ATV Action:

What sets Thumper apart from other high performance shops?

Thumper Racing:

We don’t skimp on quality. We build engines to last because breakdowns can’t be tolerated in racing or in any off road setting where a customer may be miles from help. We also give the most personal service we can.

ATV Action:

We see you’ve made some handling upgrades, too. Tell us about them.

Thumper Racing:

We wanted more cornering stability, so we went with Sedona Slingshot Tires on wider rims from Western Power Sports. We also added Rox handlebar risers to suit the taller riders. Flex handlebars soften the square-edged bumps for the rider.

RIDING IT

Thumper Racing’s 280 has the same quick, free-revving feel as the 250, but it pulls much more solidly and strongly. As a 280, the Yamaha has bottom end power that makes the machine jump out of corners, and we found we could ride our test track shifting less than normal. We could roll the throttle on for controlled slides or nail it for instant acceleration. Honestly, it’s hard to believe the Thumper Racing Raptor is only 30cc larger than stock. It feels bigger. To check our impressions, we drag raced the 280 against a new Raptor 350 repeatedly, and it won, time after time. We switched riders and lanes to check, but the 280 just kept winning. Raptor 350 riders shouldn’t be discouraged. When modified, they can become much quicker too.

HANDLING IT

As we said, we have no gripes with the stock Raptor 250’s handling. This was our first time on a track with Sedona Slingshot tires on our wider rims and we came away impressed with the cornering performance the combination provides. The Raptor 250 is fun by nature, but the tires and wheels let us slide in turns with precise control. When we wanted to point the machine straight to accelerate, we had dependable traction on hard and loos surfaces, and on the always challenging hard terrain with loose dirt on top.

WOULD WE GO 280?

When a machine is really good, there’s aways a risk of losing something if you modify it. Thumper Racing’s Raptor 280 is all gain. The fun character of the stock engine is there with more pulling power than we ever expected. The mild handling changes work great, too. If you build your Raptor 250 just like Thumper Racing’s 280, you’ll feel like you just got a new, better, bike.

THUMPER RACING RAPTOR 280 BIG BORE PROJECT

Contact: (661) 424-1800, Fax (661) 424-1888

Thumperracing.net 

17225 Sierra Highway, #119,

Canyon Country, CA; 91351