2007 Suzuki RM-Z250 #2 - Long-Term Testing - Dirt Rider Magazine

Since the initial update on the RM-Z250 Long Haul bike a few months ago (June '07), our little shootout winner has held up well to all the abuse we throw at it. Shortly after the Sunline AVone OSX handlebar was added at the last update, I threw on a pair of Sunline's trick Moto Ray Revolver hand guards as well as a set of One Industries graphics to give the little yellow bike some extra style. Aside from Ready Racing air and oil filters and another set of tires, we kept the bike fairly stock until 24.6 hours.At this point, the stock suspension was sent to Canada to see what the boys at Elka could do to improve the high-speed performance. They ended up revalving the too-soft fork, adding a 0.45kg/mm spring and a 1.6 pressure spring with some mods to improve bottoming. The stock spring rate was usable on the shock, so a revalve was all that was needed to balance out the bike. The result of this work is an initially stiff fork that is very active in the mid-stroke and much better at absorbing hard hits, especially when pushed hard. The already-stable chassis remains planted and hooked up, and the bottoming issues of the stock fork are completely gone. The beefed-up shock was likewise an improvement on fast chop and big braking bumps, while only a small amount of the Suzuki's original ability to settle in corners was sacrificed. Not everyone has liked the stiff feel, but I am way more stoked on the bike's ridability at speed, and I definitely think that Elka took the Suzuki to the next level in terms of handling.While the suspension was being worked on, I installed a Boyesen Power Wing to see how it would alter the Suzuki's strong powerband. Instantly, I noticed a difference in delivery just past the low-end, where a new smooth hit picks up even more to help pull the bike out of corners. In addition to this (and with the hot, summer weather already in full swing), I put on Boyesen's Supercooler. This is a combination water pump cover/impeller that increases coolant flow through a much more efficient internal design. One look inside the workings of the stock unit (which has the coolant taking two 90-degree turns in one spot) will prove the Supercooler's usefulness.For the most part, the RM-Z has performed well and without any major hiccups. The biggest complaint I have about the bike is in the shifting; you have to be very deliberate when grabbing gears. I've hit more than one false neutral on this bike that I didn't care for, and I've heard the same feedback from several other test riders. Hopefully Suzuki fixes this for '08. The power remains strong and the handling is still awesome, though I have recently taken to a much tighter headset adjustment, much to Jimmy's chagrin.With several local races and quite a few long test days at the track, we figured it was time to see how the RM-Z would hold up to a serious beating, but not before a good prep session. The exhaust valves had tightened up a tad but were still within spec, so we adjusted those and made sure the intakes were all good. New brake pads, tires and heavy-duty tubes were mounted, along with a fresh clutch from Barnett. Seeing as the stock plates came out in pieces, we were glad we followed through with that one! Once race ready, the Suzuki found itself entered in the dusty Glen Helen 12-hour endurance race with Jesse Ziegler, Ryan Orr, Ricky Yorks and myself on board (not all at once, mind you). Orr began the race well at the start of what was to be a 110-degree day. Twelve hours, four air filters, three rear tires, two crashes and one blown fork seal later, we crossed the line in first place in the 125-250 Expert class. The bike, as you can imagine, was exhausted.After a day of rest, the plastic was stripped and the 250F thoroughly washed. The valves were again adjusted-this time the exhaust stayed put and the intakes tightened slightly-and we replaced two worn-out cam tower bolts that had been stretched due to excessive torque at the previous valve adjust. The oil, filter, tires, spark plug, brake fluid and fork seal were changed. The next ride proved to be a learning experience; the CR8EIX plug we installed made the bike stumble and sputter with frightening consistency. Since no bike shops could find record of a stock CR8EIA plug even existing (and with everyone at Suzuki on vacation), we just tossed the old plug back in and the problems disappeared.With the 2008 250F Suzuki just around the corner, the white flag is almost in sight for our Long Haul RM-Z. Up next on the maintenance list is a much-needed top end kit, along with a new (straight) Sunline handlebar. We also plan on splitting the cases just to see how the transmission is wearing-that whole popping out of gear thing can be more than a little startling. We'll definitely let you know what we find!Running Tally
Hours on the bike: 47.0
(37.0 since last update)
Modifications: $1391.25
Elka Suspension modifications: $569.85 ($195 revalve and labor fork; $139.95 springs; $19.95 oil; $195 shock revalve; $19.95 oil)
One Industries Technoflex graphics and seat cover, number plate backgrounds, front and rear fender decals and numbers: $200.71 ($134.90 graphics and seat cover; $18.95 rear fender graphics; $12.95 front fender graphics; $26.96 backgrounds; 3 sets of numbers at $6.95 ea.)
Boyesen Supercooler: $219.95
Boyesen Power Wing: $129.95
2 Sunline Double Diamond medium-compound grip kits: $33.90 ($16.95 ea.)
Sunline Moto Ray hand guards: $69.95
Maintenance and Repairs: $1166.59 (not including tires)
Hose clamp for carburetor manifold: $3.44
Suzuki fork seal: $16.15
Suzuki dust seal: $14.49
Replacement cam tower bolts: $2.98
1 bottle Maxima Maxum4 oil: $12.95
1 bottle Amsoil Shock Therapy suspension fluid: $10.25
8 bottles Amsoil 10W-40 oil: $71.60 ($8.95 ea.)
5 Michelin rear tires (2 S12 and 3 M12): $484 ($95 ea. S12; $98 ea. M12)
4 Michelin front tires (2 S12 and 2 M12): $352 ($88 ea.)
4 rear tire tubes: $14.95 ea.
2 front tire tubes: $9.95 ea.
8 Ready Racing air filters: $9.95 ea.
1 Ready Racing stainless oil filter: $49.95
AP Brakes high-temp PRF fluid: $29
AP Brakes ORR front pads: $35.99
AP Brakes ORR rear pads: $35.99