Honda CRF250F - Modifications
Click pictures to supersize.
ALERT - Break-in starts tomorrow, Sunday, March 17.
See Break In
I modify most motorcycles that I buy. As a must-do mod, I replace the stock handlebars with aftermarket bars that I have used for many years. I like the rise and set-back, and they are aluminum, of course. I find that there are other small tweaks that I prefer, and apply those as appropriate. And I usually remove plastic that I consider useless. In particular, side number plates.
Preserve and enhance reliability (survival in the back-country)
Street-legal (DS) equipment to obtain street licensing (connect trails and areas)
So on with the show, if I can just find some room to work.
Bored reading? Take a break.
Video of Race in Brazil:
CRF250F wins the 5th Challenge...
NOTICE - Bank Angle Sensor Ignition Cut-off System
Your motorcycle's banking (lean angle) sensor system is designed to automatically stop the engine and fuel pump if the motorcycle is overturned.
Before restarting the engine, you must turn the ignition switch (key) to the OFF position and then back to ● (ON). The engine will not restart until you perform this procedure.
Page 28 of the 2019 CRF250F Owner's Manual. 0750.2018.09.K
ramz note: the BAS (bank angle sensor) function check shows:
Alphabetical table of contents
Dual Sport mods
Handlebar, grips, and handguards
Manufacturer labels and stampings
Seat bolt lock washers
Seat Concepts seat
Side number plates
Taillight and license plate holder
Modifications are shown below in roughly the order I did them.
I live in Salida, a small town in central Colorado. The nearest motorcycle shop is 60 miles away (Gunnison) with more shops in the front range 100 or more miles away. So I do most of my shopping online. I buy Honda parts from one or more of the online vendors shown in this list on the Introduction page. I buy non-Honda parts from Amazon , Rocky Mountain ATV/MC , MotoSPORT.com , and other online vendors as I encounter them in Google searches for specific products. I do not endorse nor disparage any vendor or parts they sell. I buy parts, install them, and report any features and/or problems I find. There are certainly many other vendors who sell perfectly useable products - Google is your friend.
The first thing I did when I got my 250F home was empty the gas tank and weigh the bike. It weighed 248 pounds. The bike was stone stock, no mods. All fluids checked and topped up, and the gas tank was empty.
About that number. I weigh bikes using a WalMart scale I bought 20 years ago. I don't use the scale in the house; it's strictly used to weigh things in the garage, so it gets very little use. I check its accuracy now and then by weighing myself at Dr appointments, and then coming home and see how close my scale is to the Dr's scale. It's usually within a pound or two.
So why don't my numbers match Honda or Yamaha or other moto maker's numbers? Can't really say. But I don't really care. I only care how heavy my bikes are comparing one to another. So how does 248 pounds compare?
CRF230F - 233 CRF250F - 248 CRF250L - 298
This is great! These numbers are for brand new bikes, fully set up to ride, with no fuel. No matter what mods I do (adding and removing weight), these numbers represent a base weight that is probably 95% of the finished modified bike weight.
Furthermore, the weights relate to the intended use of these motos thusly:
CRF230F - primarily technical-single-track trail riding (TST), with some dirt-road dual sport. Base 233 lbs.
CRF250F - primarily dirt-road dual sport with some TST. +15 lbs - excellent.
CRF250L - primarily dirt-road dual sport with some easy trail riding. +65 lbs - heavy, but the only choice I had.
The 50 pound drop from the 250L to the 250F should make for a very fun DR/DS experience.
The first mod - Tie-down brackets
I found these several years ago, and have been installing them on all of my bikes since. They are SO convenient to use, and make securing the bikes a breeze. Two different brands are shown here: I was trying one of each out on my 250L to see which one I liked best. They're pretty much the same, and I never swapped one or the other back so they would match up. Meh.
Shifter bolt - my favorite mod
I moved the shifter up two notches, and replaced the shifter pinch bolt with a longer bolt and a lock nut.
Yes, I did an air box mod; opened up the inlet about 50%.
My 250F needs all the air it can get; trail riding elevation starts at 8,000 feet.
There is a cast-in divider; I used it as my cut line. Finish opening size - about 1 3/8 x 1 5/8 inches.
Seat bolt lock washers
I lost a seat bolt on my CRF230F about 10 years ago, and after this mod, I never lost another. Works for me.
I have always removed the push throttle cable from dual-cable throttles. I have never experienced a stuck slide due to high vacuum on the engine side of the carb slide.
After removing the cable, the pull cable needs minor readjustment. Plug the empty hole in the throttle cable cover with Shoe Goo or something similar. Plug the empty hole in the throttle drum cover on the carb with an M6x?? flange-head bolt with a locking nut on the inside.
The throttle operates almost effortlessly.
This Moose Tach/Hour meter mounted in front of the fuel tank shows:
Total hours of operation
Number of engine starts
Wire wrap connection on spark plug wire; no soldering required.
No battery required.
With no speedometer on the 250F, nor even a simple odometer, I took the easy way out, and mounted up a Garmin Montana 610. The mount is not wired to the battery yet; I will add power when I install the dual-sport wiring harness.
Note: The stock handlebars are shown here because the new Pro Tapers have not yet arrived.
The large black plastic wrap-around piece is the Garmin AMPS rugged mount with the power cable removed for now. You can buy it from Garmin or from any one of several aftermarket GPS parts vendors. The black mounting plate is Kydex, my favorite plastic for making custom parts for my motos.
There's a small 2 x 2 inch sorbothane pad up against the back of the GPSr for vibration isolation and as a friction interface to prevent the GPSr from rotating on the cross bar.
The brake hose is nowhere near the unit; it's a perspective effect. I can slide the unit left or right along the crossbar as desired. I think I'll go for far left to keep it out of my forward-looking field of view.
Handlebar, grips, and handguards
I like the ProTaper SE in CR High, and installed them on the last 5 bikes I've owned. This time I went for the platinum grey look - and I like it. The SE (at 812 g) weighs 111 grams less than the stock Honda bars (at 923 g). I feel less vibration with aluminum bars over steel bars.
Handguard Bar End Mount kit used to mount handguards to handlebars.
First I trimmed the bars to width, which is about 30 inches or line #2 mark on the bars. Then I installed Handguard Bar End Mounts. I tapped the aluminum bars with an 11-xx tap. The bar end mounts are coated with locktite and then screwed into the handlebar ends. The handguard mounting bolts screw into the mounts with more locktite that yields a very firm, locked-in result.
Looking for an LED headlight to keep power draw to a minimum; there's only 209 watts at 5,000 RPM to be had.
No one is selling CRF250F skidplates! But I gotta have a skidplate!
Not that skimpy stock one, but a real skidplate.
I looked through my old parts bin, and lo and behold, I found an AXP skidplate. Could it work? I clamped it to the frame rails in front and under the engine, and by golly, it fit. I'll drill the mounting holes later this afternoon.
I got the skidplate mounted. Sano.
MotoSPORT has front and rear sprockets for the CRF250F. I bought a selection.
I remove the sprocket cover so mud doesn't jam up in there and ruin my chain. I was surprised to see how little room there is between the chain and the case protector. I don't think a 14 tooth sprocket will fit in there...
If you look in the lower left corner of the picture, just above the shifter arm, you can see a circular black something - that is a seal covering the hole where the neutral switch wire comes out of the tranny. You can see the black insulated wire snaking it's way up the engine to a wire bundle near the top of the picture.
The area where the wire comes out of the tranny is covered by the lower part of the sprocket cover. If I remove the sprocket cover, I expose the wimpy wire and seal to all sorts of debris from the chain. So I decided to keep the sprocket cover on the bike, but to cut some of it away so mud and other debris can still find a way out. Picture coming.
I cut out part of the sprocket cover, and will see how it works like this. I can cut more off later.
The neutral switch wire is well protected at this point.
Side number plates
Those who know me, know that I don't like number plates on bikes that I register for street use. They make the bike stand out too much, they don't do anything for performance, and they just cost money to replace after you fall on them. So I always take the number plates off and make replacement Kydex covers, as appropriate.
Kydex panel forthcoming...
Make a mockup on the bike using a piece of manilla legal folder.
Cut a piece of black Kydex using vanilla pattern.
Clean up the black piece.
Heat, trim, and shape.
Looks passable; fully functional.
I removed the shrouds, and that left the ignition coil exposed.
On the left it's bolted to the frame bracket in the stock position.
On the right, I moved it to the inboard side of the bracket, for protection.
Then I covered the bracket and coil with Kydex.
The right side with the nice air box cover is done; no Kydex panel is necessary.
I also removed the plastic cover over the rear brake master cylinder.
I removed the exhaust pipe heat shield, and the metal tab on the side of the muffler. I ground the rough spot on the muffler smooth, and painted it with some heat resistant paint. BTW, the complete muffler and s-bend weighs 5 lbs 11.4 oz (excluding the 3 bolts and 1 nut). A stock CRF230F muffler and s-bend weighs 5 lbs 10.4 oz (excluding mounting bolts).
The exhaust diffuser is inside the spark arrestor; they cannot easily be separated.
But some nimnul will try...
I used my DeWalt proctoscope to look into both ends of the muffler/s-bend. No catalytic anythings were seen, just open all the way through without any obstructions. Silencing appears to take two forms: some kind of metal mesh lining against the inner surface of the outer walls and perforated pipe in many places. But no chambers or doubling back exhaust gases paths.
Initial rides at the dealers parking lot and in my 2 acre yard (3 laps) were surprisingly noisy. Even though the CRF230F and the CRF250F are both rated 82 dBA, the 250F is considerably louder. Not as bad as the 230F with the exhaust diffuser removed, and altogether not that bad to listen to. We'll see what all-day exposure to the melody will do to my sensitive ears.
Dual Sport mods
Yahooo, most of the DS parts have arrived!
Waiting for lens/bulb
Taillight and license plate holder
I estimate that the small 1.6 gallon fuel tank on the 250F will yield about 60 to 80 mile range, depending on terrain and throttle application. For longer rides, I will mount up the MoJavi saddlebags with 1 or 2 fuel canisters, depending on my expected ride length. The following piece is taken from my CRF250L mods page, and will be modified with pictures of the 250F and the mounted bags as soon as I take that first long ride.
Giant Loop makes Mojavi Saddlebags and here's what they have to say about them:
"Specifically designed to carry just the essentials needed for a day trip or trail ride, the MoJavi Saddlebag is the slim, trim bag for inner tubes, tools, fluids and other "save a ride" necessities."
These bags are the shiznit. I bought the original design for my WR250R and now have the newer model for the CRF250L. These have an optional tool pouch.
The best tires for riding trails in the Rocky Mountains are full-on FIM-specified competition trials tires. Yep, trials tires. Run them at low pressure with tubeless rims and no better traction can be found. Rocks - easy peasy; slimy rocks and roots - laughing all the way! Hard-pack, soft-pack, and slimy dirt - goes without saying. Their only weakness is deep mud. The knob spacing is so small that mud packs in and traction drops significantly.
The top-of-the-line setup is very expensive. Trials tires are expensive and wear out quickly. Tubeless rims are like gold. So riders have found cheaper, less-capable setups, and traction is only slightly reduced. Still better than knobbies!
A step down from competition trials tires are DOT trials-like tires. These tires have the same knob spacing and similar knob shape as competition trials tires, but the rubber is harder to facilitate limited use on roads. Traction is reduced, but still better than knobbies. The sidewall is stiffer than trials tires, so some traction is lost there also. A benefit of this tire is the ability to hook up trails with connecting road sections.
Recently, some tire manufacturers have come up with hybrid tires. These tires have more space between the knobs to help clear the mud and the rubber is very soft, like a competition trials tire. Their sidewall stiffness is somewhere between trials and DOT tires. Some consider the hybrids to be the ultimate for dirt road and trail riding. Unfortunately, most of the rear hybrids are full size 4.00-18 and when used on smaller-frame motorcycles, they raise the rear end and quicken steering beyond comfortable.
In lieu of tubeless rims, riders use the less expensive Nuetech TUbliss tire system. I tried it, then I switched to mousse several years ago for maximum reliability,
So what tires do I use on my trail bikes?
For the front, I use a Pirelli MT43 DOT. I like a stiffer sidewall on the front so I can push the tire to help with steering. I also like to ride rocks aggressively - less effort in the end. Inside the tire is a mousse. Now yer talkin 'aggressive in the rocks'. I have no fear on where the front-end goes in rocks.
For the rear, I normally use a SHINKO Trail Pro 255 Radial 110/90R-18. For the 250F, I'm going with the Maxxis hybrid. I will adjust frame geometry as best I can to deal with the larger-profile rear tire. I hope the traction improvement will be enough to offset the geometry complications. I will use a mousse in this tire, also.
Text on stock front tirePIRELLI SCORPION XC
MID HARD HEAVY DUTY
XE 078B 3718
Text on stock rear tirePIRELLI SCORPION XC
XE 079B 361B
|New Trials-like Tires|
Text on the MT43 front tirePIRELLI MT43
PLIES: TREAD 2 POLYESTER
SIDEWALL 2 POLYESTER
MADE IN BRAZIL
DOT XE 23 E144 1916
MAX LOAD 165 kg (364 LBS)
AT 230 kPa (33 PSI) COLD
ON TUBE TYPE RIM FIT A TUBE
Text on the MAXXIS rear tireTRIAL MAXX
M/C 64M MST RADIAL
TREAD 2 PLIES NYLON + 2 PLIES KEVLAR
SIDEWALL 2 PLIES NYLON
MADE IN TAIWAN
LOAD RANGE B
DOT UYDD 1818
MAX LOAD 280 kg (617 lbs)
AT 230 kPa (33 psi) COLD
Other tire-related details.
The front rim is a DID 21 x 1.60; the rear is a DID 18 x 1.85
Durometer-A tire readings are (Fr,Rr): stock 65 and 75; new trials-like 65 and 50.
Yep, 50!!! Like velcro.
As mentioned previously, it's a long drive to the nearest Honda Dealer, so I order spare parts that I'm likely to need, short of a complete engine rebuild.
That $41 spark plug is an expensive spare, but if the one in the bike quits on me, I gotta have a spare handy.
Footpegs? Hit a big rock in the trail and I can limp home and replace it, to ride the next day. Same goes for the chain guide.
Air filter? Yep, gotta have a clean and oiled air filter on standby.
Seat Concepts - pending
I talked to the lady at Seat Concepts. A CRF250F seat is not on their radar now.
'Call back in a coupla weeks.'
Yeah. Got it. Please stand by.
Manufacturer labels and stampings
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