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2017 CRF450R Tech Tips


kab-pro
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Bought used bike at deep autumn of 2018. Previous owner was second place owner of UK MX1 championship. According to information bike had about 30 hours and it looked accordingly. What can you say there a lot, what is in the belly indeed.

Remaining time of autumn I spent for MX and trail riding to have a fun.5c879c1ed6b0d_CRF450R_2017(4).thumb.jpg.03f5a4105047abca6bed948b548a7fcf.jpg

 

 

Winter passed to convert bike into SM. You know, sm triples, suspension works, slipper, clutch basket, fresh piston and other small stuffs.

Inside of the engine looked as new, conrod without any free play. Even OEM clutch looked nice. One word to say perfect.

I made intake port surface smoothing and scanned it for future research.

 

WP_20180512_001.thumb.jpg.5ffddfc0e7393b7ad7d2f23eadb9716a.jpg

 

 

Last season I spent at competitions and accumulated almost 30 hours.

Schedule for this winter was to swap the piston and to take next step with head improvements.

 

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I apologize for the mistake regarding the purchase time. I got this at autumn of 2017. 
Short before last Christmas I tear down top end for piston change, once again checked con-rod, to see is there any progression with con-rod free play. Con-rod was at the same condition as it was half a year ago.

Taking in to account well known traditional problem with what facing high hours and rebuilt crankshafts I decided to check what is going on with crank bearings at about 80 hours just for interest. 

Honda's crankshafts are traditionally problematic with left-hand roller bearing inner rim. Usually bottom rebuild means swap of bearings and con-rod, but the left inner circle remains oem because it cannot be removed without pulling out cam-chain drive sprocket which is not easy. Even more,  to reinstall drive gear at correct position is almost impossible. 

So the inner circle is getting worse and worse and "half" of new bearing doesn't help at all,  free play constantly increasing, engine became noisy.

 

And to my surprise this is what I discovered.... damn, why and how

 

VID_20190115_204048.mp4

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vor 2 Stunden schrieb dr.-hasenbein:

Hey to LV  :)

 

Why ? -> build by stupid enginer without practice in repair :bag:

 

Its like Husky camshaft with beerings behind the fixed timinggear   :evil2:

I do not think they are fools, red ones don't have con-rods at spare parts list at all. They foreseen to swap whole crank. The same way all Japan 4 thinking. 

Guys from aftermarket thinking differently and has their own opinion. :D

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It is absolutely clear that the crankshaft bearings are not in order. The engine is teared down completely, next  discoveries and surprises follows. 
First I noticed this, mist bearing position locks. 

 

IMG_20190119_111027.thumb.jpg.62a8d4d748f718b1f91aa822816a334f.jpg

 

It looks like both pump was something to chewed. IMG_20190118_221555.thumb.jpg.6acd5167053886db0cfd692f904f564c.jpg

 

 

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Guest Connader

Hi Andis,

 

recently I read something about a misdesign of Oil-Volume in our models. New 19'er has more engine oil and professional AMA-Teams used to put 200ml more oil than recommended, in 17/18 as well. The issue was more related to fastly burnt clutches rather than fatal engine failures though, but you never know. :dali:

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vor 14 Stunden schrieb Connader:

Hi Andis,

 

recently I read something about a misdesign of Oil-Volume in our models. New 19'er has more engine oil and professional AMA-Teams used to put 200ml more oil than recommended, in 17/18 as well. The issue was more related to fastly burnt clutches rather than fatal engine failures though, but you never know. :dali:

 

Yes, oil is open issue. 

 

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And now pay attention to crankshafts necks. Roller side itself doesn't much surprise excluding huge wear. In video you can hear knocking, it describe how big this wear is. By the way knock test was done with oil film on parts. 

IMG_20190310_190454.thumb.jpg.de639bb58f969016996dbfde0a122f2a.jpg

 

But ball bearing (right side) seat place looks very interesting. Didn't seen such meltdown before and this makes me wondering, what was the reason.

 

IMG_20190310_190831.thumb.jpg.684a97b524d34b37a5a33fcb41d4ff16.jpgIMG_20190310_190911.thumb.jpg.64852f0bab541e5232ceadcdc416f286.jpg

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  • 2 weeks later...
vor 16 Stunden schrieb Connader:

Hi Andis,

 

the new is also OEM or aftermarket? Color of Conrod looks slighty lighter.....!?!:denk1:

Both are OEM. Right one has some history.  

Unfortunately 17 + doesn't have aftermarkets jet, but as the new one OEM costs 260$ only this isn't an issue at all. 

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vor 3 Stunden schrieb Connader:

I guess the whole assembly....?!

 

Honda prices are strange: 74,- Bucks for a Ti-Valve but 28,- for a clutch-cover gasket (the big one).:denk1:

EU market is something understandable , because crank at EU is about 850-900 Eur instead off ~ 240 Eur in US. I can't find any argue why I have to bye it in EU market.

 

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