ANYONE THAT IS RUNNING THE MIKUNI FUEL PUMP ON A 950....

Discussion in 'Dakar champion (950/990)' started by D-man, Oct 20, 2016.

  1. alon mad dog

    alon mad dog n00b

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    can you tall me wich psi i shuld looking for when i order the carter pump? thanks.
    #41
  2. veetwo _tls

    veetwo _tls RENOVATIO:

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  3. veetwo _tls

    veetwo _tls RENOVATIO:

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    #43
  4. MaineDrummer

    MaineDrummer Adventurer

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    'Liking the FCRs!!!
    #44
  5. veetwo _tls

    veetwo _tls RENOVATIO:

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    Had them since 2008 never had a problem with them except cold starting but only 5 min allowance for the usual starting
    #45
  6. beemer boy

    beemer boy Oh no, he's gone Asian

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    #46
  7. Zuber

    Zuber Zoob Supporter

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    The lower the pressure the better. Fuel regulators set about 1-2 psi work good. Any higher and you'll eventually have problems as the carbs wear or vibrate.
    #47
  8. singlewideteamusa

    singlewideteamusa Been here awhile

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    I just received this pump from Sharkshifter's website. 15679870697701251954893234729044.jpg

    I have been using the Mikuni pump but decided to give this one a whirl as it is rated for a bit more volume and uses one output line instead of two. Simpler is better, perhaps?
    #48
  9. veetwo _tls

    veetwo _tls RENOVATIO:

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    Dellorto also has one way valve = no need to use a inline tap / turn off tank taps to stop flow over night

    have one myself in spares
    #49
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  10. martinbuchmayr

    martinbuchmayr Carb 950s

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    I relocated the battery in the back and also wanted to use the vacuum fuel pump to be less error prone.
    My question now is... what is the best height for the fuel pump location? at the fuel outlet, in the middle or at the height of the carbs?

    - at the fuel outlet, it has to pump all the way up to the carbs
    - at the carbs it needs to suck the fuel all the way up from the fuel outlet

    whats better? or is the middle the best option.

    my fuel pump is a Mikuni DF52-82.

    also because of the known facts of flooding the carbs etc, it would be good to know... );)
    #50
  11. veetwo _tls

    veetwo _tls RENOVATIO:

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    Have mine mounted here

    [​IMG]
    #51
  12. bigborett

    bigborett Hipster Supporter

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    After much stuffing around I have only just now mounted mine below the tank outlets using solid nylon vacuum line.

    Have had it mounted in three different positions now including a similar one to this but using rubber vacuum line.

    In this low position it will always have positive fuel pressure at the inlet side of the pump. I had trouble with increased temperatures (higher vapour pressure of fuel) combined with decreased flow (fuel gets hotter inline so higher vapour pressure) in slow going combined with low fuel levels (negative head pressure) the vacuum pump would end up sucking vapour.

    Last time I did a 2500k desert trip with no issues and it stopped in a tunnel in traffic 40k's from home. Grabbed the tank breather, blew in it to give positive pressure and she fired up as soon as there was fuel at the carbies again.

    When in this low position before it was loosing vacuum pulse due to the flex in the side walls of the longer vacuum hose, hence the change to nylon.

    In this low position the pump is always pushing up and not trying to suck fuel up, which gets harder as temp rises.

    This has taken me a few goes to get here, I've thought I had it sorted each time. Trying to go for a nice mounting point. Each time a situation would arise that bought it to it's limit.
    The last time it had probably done a couple of thousand before the desert trip, no issues. But, the dessert trip was the first time with the Safari tank on. Lower fuel outlet and almost empty tank, more negative head pressure. Warm weather, slow going, empty tank and the stars aligned for a shit time.

    I would say mount as low as possible and if that means a long vacuum line run a solid one.
    #52
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  13. martinbuchmayr

    martinbuchmayr Carb 950s

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    Thank you bigborett for the excellent detailed explanation. So I will start with the position you recommend and see how it goes!!
    #53
  14. veetwo _tls

    veetwo _tls RENOVATIO:

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  15. Jkils

    Jkils Been here awhile

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    What are you guys with the Mikuni using for an anti-siphon valve? I have hydrolocked mine more times than I care to remember
    #55
  16. veetwo _tls

    veetwo _tls RENOVATIO:

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    I have CPC QD's on my tanks so i use a inline tap just before the pump

    [​IMG]

    [​IMG]
    #56
  17. Jkils

    Jkils Been here awhile

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    That is what I currently have too but I am looking for something that won't pass fuel if I forget to shut off the gas.
    #57
  18. veetwo _tls

    veetwo _tls RENOVATIO:

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    #58
  19. Zuber

    Zuber Zoob Supporter

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    Mount it where it stays cool and the vacuum hose is short. Pumps push better than pull. Worst place would be on top of the rear head.

    So, low on the LH side. The nylon hose is a good idea to get a better pulse, but I'd cover it with a large heat proof hose.

    The CRF450R/X hondas have a remote petcock that is high quality with mounting tabs. Should flow enough when placed on the pressure side.

    Delorto has questionable quality. Any long term reports?
    #59
  20. veetwo _tls

    veetwo _tls RENOVATIO:

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    As said showed in other posts had FCR's that fuel system setup since 2008 well way back when Ken (Powercell) & Tim had there FCR bikes & not had issue yet im in temps up to 48c here in oz

    anyway what would i know - Just Saying guess im out
    #60
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