2017 CRF 450R slower than friends

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8/4/2020 6:06 PM

Myself along with 3 other friends all bought 17 CRF 450s within a week of each other. Stock bikes, yet mine is significantly slower. Same map, fuel etc. The bike rides perfectly fine, although when I borrow their bikes it’s a noticeable difference. Less engine braking and way more power. Could this be an ECU glitch/ factory program fault? One of them removed the filter cage and I did the same, but it made no difference. Anyone else encounter this? It was an entire yr before we switched bikes, however to this day I feel like my bike is a pig.


8/4/2020 6:33 PM

Could be a lot of things. You might have a bad sensor that is causing your bike to run rich. Does your exhaust look more black inside the muffler outlet? Grab an IR temp reader and compare cyl head, top of left radiator, and bottom of right radiator between the bikes. Will need to ride them at same time and relatively same intensity/conditions.

Are you using the same oil? Different oils, especially different viscosity, can place noticeable drag on the engine and make it feel slower. Also, excessive oil level can make the engine feel slower.

Excessive air filter oiling can bog an engine down, although this is more relevant to 2-strokes.

TPS setting?


Has the engine ever been apart? Maybe the cam chain is off 1-tooth on the cam?

Since you have multiple bikes there, you could swap ECM's to eliminate mapping.


Powerband in every gear !

8/4/2020 7:06 PM

Motor, exhaust are bone stock. Never been opened up, same Honda 10-40 oil, same air filters and filter oil brand. I would have never thought anything of it. It rides fine, still fast but compared to my friends identical bike his feels like it has work. I have 46 hours on it, broke it in properly, oil changed every 3-5hrs, air filters every ride. Maybe it’s a sensor or airflow issue, but it’s pretty drastic. It’s not broken; just might be sending the wrong data to the ECU.


8/4/2020 8:58 PM

I'd start swapping parts between your bike and one of your friends' bikes to figure out which part is making the difference. Ride them between swaps to see if it made a difference. I'd start with the ECU, then the injector and go from there. Eventually you'll find the problem.


8/5/2020 10:28 AM

How do the sounds of the bikes compare? Try "cracking" you throttle from idle to see if it bogs. Do your wheels rotate freely when its on a stand, and are you running much lower tire pressure?


8/5/2020 12:57 PM

Have you changed the top end yet at 46 hrs? I had a 14 CRF450 a few years ago, piston was quite worn and the wrist pin was very worn and grooved at 35hrs. A new top end might bring yours back to life


UK Vet rider - 2020 KX450

8/5/2020 5:11 PM

That’s really strange. Have you checked your Valves? I have the same bike and I haven’t even checked mine at 128 hours haha. Need to do that soon. I’ve never touched the top end or the motor in general on mine. It’s been a super solid bike for me. Hell, I haven’t even had a bolt back out. Anyways, At 57 HP that bike shouldn’t feel slow.... Mine definitely doesn’t! Maybe you should send your ECU to twisted designs or Tokyo Mods and have them map it and set up properly.


Don't ever let facts get in the way of a great story

8/5/2020 6:16 PM

Swap Ecu’s first. Rule that out first.


8/6/2020 10:45 AM

If it had a bad sensor wouldn't it flash a code? maybe you got one built on Friday afternoon?


8/6/2020 7:49 PM

I’d lean towards tps setting. Are you in the aggressive map? Proper slack in the throttle cable?


8/6/2020 11:00 PM

A friend that worked for an oem said they'd take around 5 new bikes (same model) out and test. Some were faster than others, I didn't ask why. This was in the 2000's.


1980 trail70, 84 xr80, 84 cr125, 93 cr250, 04 crfx250, 74 Husqvarna wr450, 08 crf450, 87 cr80, 05 crf450, 16 fc250, MCR 19 crf450, 05 crf250, 17 rmz250. Thanks EKS, O'neal, Bell, SIDI and @kylelewis23mxacademy

8/7/2020 3:59 AM

Throttle has minimal slack, but enough to keep it from idling up. Any map, but I run it in aggressive mode. My friend runs his on the medium map and still has more torque. Don’t get me wrong it’s a 450 and still has power, but feels down on power compared to the other Honda 2017’s I’ve tried and the engine braking is far less. I’m leaning toward improper feedback from something to the ECU. It’s to the point where I borrowed his bike, landed a jump and felt like I was on a 2-stroke with no engine brake. The following corner is a seat hop triple/double combo and my bike takes everything it has to downside it correctly. His pulls and pulls, mine runs flat up top and I’ll just wind it out in 3rd gear like I’m on a 250F. I’ve experimented with gearing too and came back to stock. I think I got a lemon. I recently installed a recluse clutch and the engine braking is far less but for obvious different reasons. 0 engine work, and like I said I would have never known until I rode their bikes and now feel like I’m a couple HP down in comparison. Based on what everyone said I have to believe it’s ECU data and output.


8/7/2020 5:03 AM

yours must have been built on a Friday afternoon


8/7/2020 6:52 PM

There's a reason "blueprinting" is a thing


8/13/2020 11:54 AM

Could be the difference of a Monday, Wednesday or Friday bike or motor. I had the same issue years ago but with my Evo 9. A few buddies and myself all had them and my buddy happened to make almost 10% more power with less performance mods than my car had. When speaking with the shop and tuner the explanation was that his was likely a Wednesday car. Basically a motor built in the early or late part of the week would be less dialed in than a motor built in the middle of the week. We took a look at the porting of the heads and noticed a clear quality difference in mine vs his. Mine had sharp edges and grooves where his was smooth and clean.


2015 YZ250F - 2003 CR125R

8/13/2020 1:43 PM

I was watching Deegan's livestream a few weeks ago and their stock 85 race bike has like 2 more hp than the others because they dyno'd like 10 stock bikes to find the fastest of them. Could just be tolerance discrepancies from the factory. These bikes are mass produced after all.


8/13/2020 6:02 PM

Also it could just be that clutch is worn.