TWO-STROKE TUESDAY | 2005 HONDA CR125 FULL TEST

This archived 2005 Honda CR125 Motocross Action Magazine article was founding the March 2005 issue. 

If you were like us, you were getting  nervous that Honda was dumping their two-strokes for 2005. When the CRF250 and CRF450 were released in July, Honda didn’t even have a photo of the 2005 CR two-strokes to show. Even worse, they weren’t even mentioned. To their credit, every time we asked about the two-strokes, Honda assured us that they were coming, but that they would be late.

There are only two possible explanations for why the CR125 and CR250 would be delayed:
(1) Honda had lost faith in the CR’s sales value and had used its previous production time for some larger selling model, like the CRF250. Thus, the pushed the two-strokes back on the schedule because they weren’t as important to the big picture.
(2)
The CRs were undergoing serious remodeling and Honda’s engineers needed more time to finalize all of the changes. This isn’t uncommon (the Suzuki RM-Z450 four-stroke was pushed back four months for fine tuning).

What was the real reason? In our opinion, it was a little of both. First, it’s no secret that the market place is a four-stroke world right now. So, Honda held up the two-strokes to focus on the four-strokes. Second, Honda did put serious effort into fixing the flaws that have held the CR125 and CR250 back. The redesign probably needed more time–which is why the 2005 CR125 and CR250 got back-burnered.

They were late, but they are here now. Will the healthy list of changes to the 2005 model help bring it to the front of the pack?

Q: IS THE 2005 CR125 FASTER THAN THE 2004 CR125?

A: What isn’t? Last year’s 2004  CR125 was slow. The engine package wasn’t competitive with any other 125 in the class. Worse, it wasn’t even close to being competitive with all the 250Fs on the track.

Is the 2005 CR125 better? Yes. The 2005 CR125 is much faster than the 2004 model. In fact, it’s now competitive with the rest of the 125s. As for the 250Fs, let’s not get too greedy.

2005 HONDA CR125

Q: WHAT IS THE BIGGEST CHANGE ON THE 2005 CR125 ENGINE?

A: Remember that high-tech electronically-con trolled power valve that Honda ballyhooed on the 2004 CR125? It’s long gone. Honda returned to a more traditional, governor-actuated, four-ball power valve. If you think this is a technological retreat, you’ve been watching too much G4TechTV.

None of the MXA wrecking crew are weeping over the loss of the electric power valve. In truth we are hoping they will go mechanical on the CR250 next year. The old-school power valve is an improvement.

2005 HONDA CR125 pipe and engine

Q: WHAT ELSE WAS CHANGED ON THE CR125 POWERPLANT?

A: Honda rounded up some of the usual suspects for modification. Here is the list.
(1) The cylinder is all–again.
(2) The intake and exhaust ports have been reshaped.

(3) The piston has been redesigned with a new keystone ring.
(4) The power valve is a NSR road racing-inspired rotary flap design. The new valve has more overlap to minimize exhaust gas leakage.
(5) A new six-petal reed cage has stiffer and larger petals.
(6) The compression ratio was lowered to 8.6:1 for more rev.
(7) Honda redesigned the crankcase to accommodate the new reed cage.
(8) Shifting has been improved with a new shift fork shaft, shift forks and shift drum. Also, the shift shaft has a new surface treatment.
(9) The exhaust pipe has been reconfigured to work with the new cylinder porting.
(10) Radiator core depth was increased from 24mm to 28mm.
2005 HONDA CR125 rc valve

Q: WHAT DID THEY ACHIEVE WITH ALL THOSE CHANGES?

A: A ton. The CR125 went from cellar dweller to the pent house.

Q: WHAT DID THE MXA TEST RIDERS THINK AFTER THE FIRST RIDE?

A: They didn’t like the CR125. Why not? Bad gearing. We’ve been battling this problem for years. Manufacturers, especially Honda, love to equip their bikes with tall gearing. Why? They want the bikes to pull as long as possible in every gear. On a trail, in the hands of a National Pro or while play racing, this is okay. But, for racing you need to have close gear ratios that offer the maximum power focused into the correct places.

With the stock gearing the 2005 CR125 doesn’t like to make the jump from second to third without falling off the pipe. What’s the fix? Replace the 52-tooth rear sprocket with a 53. This simple change makes a world of difference. Test riders who were disappointed with the 2005 CR125 with the 52, loved it with the 53.

 

2005 HONDA CR125

Q: WHAT DOES THE 2005 CR125 RUN LIKE?

A: Previous CR125s had a very narrow powerband (mostly in the middle). The new CR125 has lots of middle and plenty of top. The ‘05 CR125 pulls strong, but you’ll have to use a little clutch to get the bike into the meat of its powerband.

So what’s the best way to ride the 2005 CR125? Use the transmission for all its worth. Honda still has a five-speed tranny (we preferred the old six-speed), but they spent lots of time working of the shift shaft, forks and drum to make shifting effortless, so use it. Slam the bike from gear to gear to take advantage of the mid-and-up powerband. You’ll work up a sweat, but the breeze you generate will cool you down.

Q: WHAT ABOUT THE STOCK JETTING?

A: It wasn’t terrible, but it was a little lean on top (which showed up as pinging under a load). The solution? Go to a 440 mainjet, a 27-67 needle (in the 3rd position) and a 50 pilot. As a final step, carefully adjust the air screw whenever the temperature changes. We normally set the aircrew at 1.75 turns out. These settings are baseline for our sea level SoCal race tracks.

Q: HOW GOOD IS THE CR125 SUSPENSION?

A: Very good. When the tech specs first came out for the 2005 CR125, they claimed that Honda would be making a fork change. The specs lied. The ‘05 CR125 has the exact same suspension that it had in 2004. That’s not a bad thing in our book. We loved the suspension last year and we love it again this year. Don’t get us wrong, we would’ve preferred to see the 2005 CR125 sporting the new 48mm Kayaba forks that grace the 2005 YZ125, but by standing pat they didn’t risk taking a step backwards on the settings.

2005 HONDA CR125 forks
Forks: We left them alone. They come standard with 0.44 kg/mm forks springs and good valving. Set the compression on 14 out and the rebound on 10 out.
Shock: Just like the forks, Honda didn’t mess with a good thing. The spring rate is 4.7 kg/mm. Our best setting was with the low-speed compression on 10 out, the high-speed compression at 2 turns out and the rebound on 12 out.

We set the sag at 100mm, although you could run it as low as 105mm if you feel the bike is riding high in the rear.

2005 HONDA CR125 rear shock

Q: WHAT DID WE HATE?

A: The hate list:
(1) The grips: Honda grips last forever. They will shred render hands before they ever wear out.
(2) Gearing: Gear it down or be prepared to burn up clutch plates.
(3) Rear brake: Brake draggers will still get the rear brake to overheat. If this isn’t you, don’t worry about it.
(4) The forks: Hey Honda, what happened to those 48mm Kayaba forks you promised? We’ll forgive you this year.
(5) Tires: We commend Honda for ditching their fascination with the old Dunlop 495/695 combo, but the new Dunlop 742/756 combination is a little unbalanced. We’d like to see them switch to either a 739 or 756 front tire.

2005 HONDA CR125 rear sprocket

Q: WHAT DID WE LIKE?

A: The like list:
(1) Suspension: Finally a company who leaves their suspension alone when it’s good.
(2) Reliability: Honda prides itself on reliability and for good reason. The CR125 is built Honda tough.
(3) Power valve: We love the retro power valve.
(4) Components: Nothing is built like a Honda. The frame is great, the clutch flawless, the front brake awe inspiring, the swingarm a piece of art and the hubs light beyond belief.
(5) Ergonomics: You just feel good sitting in the CR125. The Renthal handlebars are in the right spot as are the footpegs.
2005 HONDA CR125 clutch perch

Q: WHAT DO WE REALLY THINK?

A: In a surprising turnaround, every MXA test rider liked the 2005 CR125. It is a very capable 125cc tiddler. Best of all, it has all the charms that Honda is famous for (reliability, handling, quality and suspension). If you’re looking for a two-stroke that will last forever and be competitive, but not omnipotent, give the CR125 a look.

2005 HONDA CR125
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