The Africa Twin XRV650 & XRV750 thread

Discussion in 'Land of the Rising Sun: ADV Bikes from Japan' started by iswoolley, Aug 23, 2004.

  1. GSPD750

    GSPD750 Adventurer

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    Check the airbox rubbers to the carbs and make sure they are secure and have not popped off due to overtightening of the clamps. Never torque them tight like an ordinary hose clamp or you will not get a proper seal.
    You could also check for a vacum leak from the 2 sources above the carbs where you would tap in to source a Scott Oiler or a previous vacum fuel pump.
    Choke plungers working correctly? You have 12 volts at the pump I'm assuming when it's running?
  2. Reidy008

    Reidy008 I,m in if we go fast

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    I had the same problem and it was a blocked fuel filter between the petcock and the fuel pump.
  3. RiderMakis

    RiderMakis Adventurer

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  4. GSPD750

    GSPD750 Adventurer

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    It's quite possible. :thumbup It's always something simple that fixes it in the end...well most of the time. :D
  5. al bowlly

    al bowlly Adventurer

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    I can only hope. Thanks for the suggestions.:thumbup:thumbup
  6. GSPD750

    GSPD750 Adventurer

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    It's an old topic I know. I'm looking at improving my front suspension as that's one area on my AT that has been neglected. To the best of my knowledge
    the springs are OEM and I've serviced them once or twice by draining and replenishing fluid...and that's about it other than I do have a quality rear Wilbur's shock.
    The dive I've been experiencing as of late is now becoming a safety issue.

    Now I just read the informative post from Ray 4325 regarding Ricor Intimidators. From what I understand they work best with the stock springs...correct? So...anyone
    installed these on their RD07A?
    http://store.ricorshocks.com/product_p/043-20-1001at.htm
    Anything I need to know Ray? Is it plug n' play? Installing these intimidors is an option for me to buy from the USA and not have to have progressive springs shipped over
    from Europe such as wirth, hyperpro or Yacugar. Not to mention shipping cost for those heavy springs. Thanks.
  7. Bli55

    Bli55 -

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    GSPD750, have you considered Race tech Emulators? :1drink
    Thay seem to be of somewhat superior design...
  8. GSPD750

    GSPD750 Adventurer

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    Yes..I've heard of them but I don't know much other than they may require tuning such as drilling damper holes in the tube etc...I want to keep it simple.

    http://www.advrider.com/forums/showthread.php?t=663755
  9. Ladder106

    Ladder106 It's a short cut, really

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    Pretty much an easy installation. Make certain you use the specified brand and weight fork oil. I know it seems like all 5 wt oil should be the same but practice has proved it's not.

    The Racetech product is good but does require fork leg disassembly and drilling huge holes in the damper rods. Ricor get around this by using very light oil so the standard rebound holes are effectively not in play.

    Racetech also operates on a "pre-set" compression value. Ricor is dependent on upward acceleration of the forks on bump so is a bit more "reactive" to changing riding conditions.

    The standard springs should work fine. The Intiminators will add a bit of preload to the springs but I'd bet you could actually add a bit more if the springs are old and I think you ride with boxes and stuff all the time.

    Shoot for about 2 in. of front fork sag with you on the bike. If this is not achievable with your standard springs, using a higher rate spring will be a good idea.
  10. GSPD750

    GSPD750 Adventurer

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    Thanks Ray! Nice to have a resident suspension expert on board. I see on their website the 43mm intiminators for the AT are
    already sale priced at $179.99...I wonder if an ADVrider member qualifies for a further discount. I seem to have heard that on
    another post here...or maybe that offer expired. Won't hurt to ask eh?
  11. @dreamer

    @dreamer Been here awhile

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    Ladder, a quick question regarding using original springs with the intimidators I have an RD04 and assume that they are original springs, is there a way to determine if the springs are good, I mean after 22 some odd years they are probibly not up to any kind of spec. So are new/original springs required to get the full benifit from the intinimators?

    On a different note I am experiancing an extreamly strange problem, while driving after 10 min or so the bike.starts acting up like.it is having a fuel supply issue. If I hold the throttle steady it pulses up and down a few 1000 rpms, then I noticed that the tach goes dead with the higher rpms then comes back as the rpms start coming back down. At first I thought that it had to be carb related but with the tach going crazy that seems electrical. Any one willing to bite at this one, I just hope that I'm not going to be chasing down two problems at the same time. I will be going back to civilization around the 1st so my first job is going to be is to get some carb cleaner and get the carbs out for a good cleaning and go from there.

    Any help will ne greatly appreciated
    Keith
  12. alainmax

    alainmax ca vaut le detour !!

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    Mmm....... CDI ?

    Wayne, i have the intimators and like them alot. Should fix your front dive issue. i believe i have the 4.0 a little softer than the 5.0. Easy install as meister Ray mentioned

    as a side note, will be in Chile in January, en route for Ushuaia :clap
    Greetings to all
  13. ujeni

    ujeni just doesn't get it

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    If the tach is acting up then that points to a CDI issue (one of the CDI unit powers both a cylinder and the tach). Quick test would be to swap CDI units with another rd04 if you can. The other test would be to swap the CDI units on your bike and see if you have the same issue. My guess is that you would have the hesitating, but not the tach behavior. That would point to one bad CDI unit in my mind.

    Unless your springs are in terrible shape, you should be able to use the old ones with the intiminators. A quick length check on the springs checked against the manual should give you a clue on their condition.
  14. Ladder106

    Ladder106 It's a short cut, really

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    Not at all. But you may be sorry you asked. There a lots of suspension set-up articles on the interweb. I'll give you the important points here:

    A spring is nothing more than a torsion bar (a piece of metal that is held in place at both ends and twisted). After numerous bendings the character of the metal changes a bit and it doesn't "spring" back to it's starting point like it did when new.

    With springs this results is the overall length becoming shorter ("sacking out") and likely also becoming less able to resist twisting (getting weaker and lowering the spring "rate").

    But this does not mean the spring is bad.....unless is breaks.

    Any spring is OK as long as it's correct for you. The way to determine this is to measure "sag"....or the distance the suspension compresses under 3 conditions.

    1st...measure the distance between the top of the fork and the bottom triple clamps...if we're talking about forks. For the rear measure the distance between the rear axle and some fixed point on the top rear subframe.
    Take this first measurement with the bike on a lift or center stand with all weight off the suspension.

    2nd...measure the total suspension travel available. This can be done the hard way by direct measurement with the fork caps and springs removed or simply by reading the service manual specs on suspension travel. I've found the service manuals to be just a bit inaccurate but not enough to affect the calculations unless your a all-out racer guy.

    3rd...(You'll need at least one assistant here-two is better). Take the bike off the stand, gear up with your normal riding attire and put your normal riding load (water, spares, panniers, etc) on the bike. Sit on the bike and have one assistant hold the bike upright. Hold the front brake (this is important for old forks with worn bushings. The angle of the tubes can cause minor binding and not allow the forks to compress normally at rest...so hold the front brake on).....Bounce your butt up and down on the seat a few times to allow the springs to settle and the damping oil to move.....THEN have your second assistant measure the same points at were measured in Step #1.

    This measurement is referred to as "RACE SAG"...just a name to denote the amount your suspension compresses during normal riding.

    4th...Get off the bike, hold the bike vertically. This time you're only measuring the weight of the bike (including normal riding load, panniers, etc) on the springs....and....guess what.....yep, take those same 2 measurements again.

    This measurement is referred to as "STATIC SAG"

    Pant....pant.....takes longer to type than to actually do.

    OK, now you know:

    Suspension travel.....lets say 200mm for front forks for example
    Race sag.................lets say 100mm for example (this is likely what you'll find with an old AT or Transalp)
    Static sag................lets say 50mm for example

    So what does this mean....well, it varies. In general for bikes used off-road you're looking for about 25% RACE sag, so, in our example, the suspension is dropping too much. This means (a) the springs have gotten old and weak (b) you weigh (for whatever reason) more than the manufacturer allowed for when the bike was built or (c) you have more of a load on the bike than most riders with that model.....or some combination of "all of the above"

    What do you do now????

    Well, the easiest and least expensive thing is to go get some cheap easy to work with material and build some spring spacers. For the forks....PVC pipe it what I use. It's cheap, easy to cut and works just fine.

    So we cut a piece of PVC to....oh....40mm. Stick that about the spring, put on the fork caps and.....yep....take all the measurements again.

    So this time we get:
    Total travel: 200mm....stays the same
    Race sag: 150mm
    Static sag: 2mm (WTH????)

    So, we've achieved our 25% race sage measurement and we think we've solved the problem - But - look at the static sag measurement. With just the weight of the bike, the suspension didn't move "at all"..

    This is where the static measurement comes into play ( and where suspension tuning breaks into art and personal preferrence).

    Our static sag measurement is telling us that our spring rate is too low. We got our correct race sag but at the expense of too much spring preload. Right now the force necessary to START the suspension moving is too high and the suspension will feel harsh and not react much to smaller bumps.

    This is why the static sag measurement is important. It tells us that we should increase (or decrease) the spring rate.

    For me (this is personal preferrence) I use about 25% race sag with a static sag of about 35-40 mm.
    ______________

    Now you get to do the same with the rear. This time you crank the preload collar on the rear shock up and down (lots of lube here please) to change the preload.
    ______________

    A word on springs: Many manufacturers particularly the Japanese routinely provide bikes with soft springs that are made for a 180 lb. rider and no extra gear. It's common to buy a new bike and have to change springs if you're an average sized guy and carry spares, food, etc. If you really want to drive the dealer nuts...do this in the showroom when buying new and ask for a spring change to be included with the bike. What happens next will determine whether you're at a good dealer or not.

    So this is how you do it. Takes an afternoon with a few friends. If you know 2 other riders, you can do everyones measurements in an hour or so.....then the fun starts.
  15. GSPD750

    GSPD750 Adventurer

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    Thanks for taking the time and posting that Ray! I managed to read it without my head exploding. I'm think I'm going to go with Ricor's and I'm sure it will be $ well spent. I will be emailing them shortly. It will be interesting to see the service limit on those springs once I remove them. Standard on the lower spring is 564.1 mm and service limit is 552.8 mm.

    Alain...have a safe trip while in S.A. I assume you're renting and if so what have you chosen? I would love to round up a group and and rent some DR650's out of Quito Ecuador again. An Amazon/Andes combo ride would be gauranteed to be a memorable one. Safe and inexspensive too.
  16. alainmax

    alainmax ca vaut le detour !!

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    Ray, great write uo, as usual..thank you for taking the time to share the knowledge/experience.you should organize a tec day on carbs and suspension !!! I,m IN !!

    Wayne , i can only take 4 weeks and i heard horror stories on bike being shipped in SA and stuck in customs up to. 2 weeks !!! Can t take that chance so yes we rent in SanTiago de Chile

    Great news is we get. Tenere 660 !!!!!:clap
  17. coyotetrips

    coyotetrips Traveller

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  18. Ladder106

    Ladder106 It's a short cut, really

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    I've been in love with that bike since it's introduction. Please do a write up and comparison to the other bikes you own/have ridden.
  19. john_aero

    john_aero Long timer

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  20. @dreamer

    @dreamer Been here awhile

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    OK, now you guys a scaring the crap out of me, at $600 plus for a used CDI from hamart and who know the condition, is probably enough to scare the crap out of anyone.

    Ujeni, you said one of the cdi's my bike only has one so swapping isn't going to be a possibility. As far a getting another one from someone that also isn't going to be possible so I don't know what I'm going to do???

    Ladder, thank you for the write up I will have to look at my situation after I figure out what I'm going to do about this possible cdi issue.

    Keith