CRF based Rally Bike Help

Discussion in 'Racing' started by doyle, Jan 26, 2013.

  1. doyle

    doyle RallyRaidReview-ing

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    So I know a guy....

    Actually Chavo asked me to inquire the minds about either A) putting a carb'd (pre-2009) CRF450R motor in his Team Honda Europe 450X rally bike or B) Adapting the tanks, nav, etc.. from the CRF450X onto a CRF450R.

    Anyone familiar enough with the specifics of the motors?

    Some drawbacks of the R for rally would be the closer gearing, perhaps too close for the long hours and longer liaisons? Also as far as I know, there is no electric start on the R's, correct? The R is also a higher compression, could lead to detonation problems at altitude and heat, perhaps?

    His major mechanical problems in Dakar were mostly stator related. He had a few let him down and is looking from some assurances from Team Honda Europe that they can correct the problem but Chavo is looking to flush out some ideas and asked me to gather the wisdom of the collective. I pondered putting this in Thumpers, but the intent is more rally related so I wanted to keep that perspective on the overall discussion.

    Thoughts anyone?:ear
    #1
  2. xr400r

    xr400r Long timer

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    i am quite sure that the r has a closer ratio transmission than the x. how that would be for rally biking i dont know.
    #2
  3. schattat

    schattat Long timer

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    I have heard of many cases where the stock stator of the Honda 450X has failed, I believe the Honda Europe bikes had the Trailetech DC upgrades. Not 100% sure, but I believe a newly made wiring loom is the best solution ot cope with the upgrade. I did that on my WR450F, prior to the stator upgrade, also a Trailtech, there were somethings I wasn't happy about. E.g. the small stock ignition switch would also pass the current that was required for the headlight, so several amps went through the mini on/off switch. Just my 2cents.

    Tell him he can get in touch with me, I can sort something out together with him and Henk from Honda! :beer
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  4. Strong Bad

    Strong Bad n00balicious

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    Many of the D-37 desert racers use the CRFX as a base. Having done it myself allow me to add a couple of things:

    The R does not have the magic E button.

    The R close ratio gear box is too close for desert usage (and assuming Rally Raid).

    Many guys use R cams in the X head and there are different tuned cams that come on different years X & R.

    Not uncommon for guys to swap the X head for the R head.

    The R uses a 19" rear wheel, the X uses a 18".

    Not sure about the newer bikes in the last couple of years, but the at one time the X had larger radiators.

    I know that you can't directly fit an R pipe onto a X, how much of that is due to the different shrouds, tank size, or if the mounts on the frames are different or what.

    If it was me I would start with the X, and I'm pretty sure that what JCR starts with for their Baja bikes.
    #4
  5. doyle

    doyle RallyRaidReview-ing

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    Thanks guys, all great stuff and I think just what Chavo is looking for.
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  6. doyle

    doyle RallyRaidReview-ing

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    Juan Carlos had two main frustrations, the stator, and the fact that he'd push in the technical sections only to get onto some open ground and have the other bikes blow passed. He was topped out at 158kph. He'd like to be up pushing 180 as some of the other bikes are.
    #6
  7. Yellow Pig

    Yellow Pig Allergic to Asphalt!

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    Wow, those are crazy speeds for a 450cc bike.
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  8. Mudguts

    Mudguts when in doubt GAS IT

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    Some of the limitation of using the small 450 mx base engines are the gear box ratio's if you have $$$$
    You and get custom gears made . No doubt some of the big dollar teams would have done this ,
    Or hybrid MX / Enduro gear box .
    #8
  9. schattat

    schattat Long timer

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    Yep, the factory Yamaha 450s had/have that, some gears from various bikes, 250, 426, 450, ro make a Frankenstein Setup! :D
    #9
  10. Blur

    Blur 3MTA3

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    I may be getting the 250X and 450X problems mixed up but....from what I understand, you probably want to swap out the valves also. Stock valves don't like long, sustained high rpm. I've heard good things about aftermarket stainless steel valves.

    Thumpertalk would be a good resource: http://www.thumpertalk.com/forum/80-crf450x/
    #10
  11. Aussie66

    Aussie66 Been here awhile

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    To be in the top 20 you need a fast bike, to finish you need a reliable bike, strangely enough those two things dont go together too well. The KTM is probably at the moment the more reliable pro rally bike. And the top KTM guys are already calling it an old bike because its heavier than rest of the pack.

    We, the followers look at a rally bike and think reliability (more from days gone past), The factory boys need an engine that will last 7 days. A 7 day engine = an enduro engine. Thas what the rally has essentially become.

    As an amateur I think the route Jmo Piglet has taken is the route for the amateur. Absolute reliability. Time to dust off a 690RR.

    180 km/hr out of a 450X and make it last??? One can only hope.
    #11
  12. rmhrc628

    rmhrc628 Long timer

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    You need to r ify the x motor. I spent $5000 doing that.

    Change the head, carb and valves over to r model parts. Radiators. Porting. Open the air box.

    You need to keep the x base.

    Switch the r model swing arm in too.


    Why was the yzf so good - presumably it's gearbox is very tight like the CRF r model? They did fantastic in Dakar 2013.
    #12
  13. doyle

    doyle RallyRaidReview-ing

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    Juan Carlos will chime in here tomorrow. For this Dakar, he did use the standard battery but still had stator problems. He's been reading through and really appreciates the information.
    #13
  14. rmhrc628

    rmhrc628 Long timer

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    Is he running genuine rewound stator or aftermarket ?
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  15. Luke

    Luke GPoET&P

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    If you could be more specific about 'stator problems' and post up a wiring diagram of the bike (or at least of the stator part) and some details on the stator/regulator/battery/etc that'd be helpful.
    #15
  16. chavo_dakar_bolivia

    chavo_dakar_bolivia Adventurer

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    Hello advriders!
    Thanks for your comments and insight.
    I want to share with all of you what has been done and used in this Dakar.

    In Sardegna rally, I dnfed on the last stage, and was using a stock stator with Super B Battery and STOCK headlights.
    First i had thought it were the LED lights that were causing the problem, so this theory got discarded.
    The second theory of the problems were oil coolers and/or heat. This also got discarded because in Sardegna I had no oil cooler and the stator failed 100m from the start. (cold engine still).
    Third theory was the Super B battery. I was using a stock battery in Dakar, and still the stator failed. So this theory is also discarded.

    In Dakar, I was using a Trailtech stator with a stock battery.....and it also failed.

    So I have in mind experimenting with bolting on rally accesories (tanks,navigation tower, etc etc) on a 2008 CRF450R.
    Some say the gearing is too close, but I believe only 1,2,3 gear are closer. 4th and specially 5th, are better on the R model.
    The weakness of the X gearing is its 5th gear...it is too tall and the engine doesnt quite pull it.

    So with these clarifications, what do you think?

    Thanks for the advice.
    #16
  17. Luke

    Luke GPoET&P

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    So when the stator fails, what happens? Does the bike completely stop running? Do the lights or instruments stop working immediately? Does the battery stop charging?
    #17
  18. chavo_dakar_bolivia

    chavo_dakar_bolivia Adventurer

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    It is the exact same thing as if it were running out of fuel......
    I was going full on and suddenly it stalls and feels like it ran out of fuel......
    #18
  19. Mudguts

    Mudguts when in doubt GAS IT

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    Do you know how many watts your stator produces ?
    Do you know how many watts you are using ?
    Is you reg/rec working , properly no spikes etc etc

    Have you checked for bad / loose ground contact points ,broken wires , this can produce a feed back signal and fry stators
    Same with positive bad contact will cause things to over heat .

    With two different stator frayed , I,d be looking at reg/rec , and ground contacts
    #19
  20. Luke

    Luke GPoET&P

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    Ok, so that should have nothing to do with the charging system or battery. The ignition wiring is independent of these.

    It could be either the high voltage coil on the stator which powers the ignition, or it could be the timing pickup which tells the ignition when to fire. The timing pickup is usually replaced with the stator so it could be either.


    In this picture the pickup is the plastic bit on the lower right with the blue and green wires going to it.
    [​IMG]



    A resistance test should tell you which one is bad. I don't have a manual so can't tell you what the exact values should be. Sometimes when either part fails it will start failing when hot and work again when it cools off, then fail more often until it never works.
    #20