Results 1 to 13 of 13

Thread: modded minimoto keeps blowing reed valves

  1. #1
    Join Date
    7th September 2005 - 08:05
    Bike
    ZX9R, KLF300 waverunner tower :)
    Location
    Auckland----------south
    Posts
    350

    modded minimoto keeps blowing reed valves

    Is anyone having reed blowing issues ??we seem keep blowing reed valves the PBU headstrong kit is so high compression that on the downstroke the reeds are trying to exit the engine via the carb

    2 runs and the reeds are fucked. is anyone else popping the std metal reeds

    today we fucked around with the fully tricked up bike for a bit and it shat itself - another set of reeds after 2 10 min runs

    then we gave up on that and put the race pipe on a std day 2 that had the needle lifted up one notch, it actually went better than the modded one for about 10 mins then seemed to loose power. couldnt be fucked pulling it down to see what the problem was, dont think its reeds cause it still idles, when you open it up it wants to die now, im wondering if the fuel/oil is too lean, and its getting hot after a little bit and the extra drag on the piston is robbing it of powers? the mix is 40:1 using castrol r30 (not my pick but what my mate likes running) it has some caster in by the smell of it.

    need to get some carbon or fibreglass reeds for the std block ...Beast can you help there ?

    see you cunts later, its a nice day for a ride, pity ive had too many beers
    Matty C

    Have you taken your bike over any sweet jumps?

  2. #2
    Join Date
    13th February 2004 - 06:46
    Bike
    Forza 155 SE Pit Bike
    Location
    Wellington
    Posts
    11,471
    Well us "cunts" reckon you've got the wrong kit on it. Try running two base gaskets. Some thing's obviously not right.

    Did you change the crank?

    Mine started first try, runs faultlessly and (now) has no issues.
    Vote David Bain for MNZ president

  3. #3
    Join Date
    30th October 2005 - 20:07
    Bike
    ZPF Rep, GP3 Rep, B2 (alloy B1)
    Location
    Wellington
    Posts
    211
    Yeah that's what you get for not buying from Xtreme aye Jimmy

    Yeah I think we might have some carbon reeds for the standard reed block.
    PM me

  4. #4
    Join Date
    7th September 2005 - 08:05
    Bike
    ZX9R, KLF300 waverunner tower :)
    Location
    Auckland----------south
    Posts
    350
    Cheers "Cunts"

    WT do you also have the PBU headstrong kit ? the crank and rod is standard, we are actually beginning to think the piston may be wrong as it has windows in it and they dont line up with anything, i think its meant for a 4 port barrel the barrel is a 2 port fked if i know

    http://www.pocketbikesunlimited.com/49YELLOWJACKET.html - this is the kit, the barrel look different

    Beast - we have made some fibreglass reeds, are yet to test, will get some CF ones off you if these are all shit
    see you later
    Matty C

    Have you taken your bike over any sweet jumps?

  5. #5
    Join Date
    30th October 2005 - 20:07
    Bike
    ZPF Rep, GP3 Rep, B2 (alloy B1)
    Location
    Wellington
    Posts
    211
    WT has a kit, but its the Xtreme Power Machines equivalent to what you're talking about

    Here it is:
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	d12barrelkit49cc.jpg 
Views:	17 
Size:	65.6 KB 
ID:	21513  

  6. #6
    Join Date
    7th September 2005 - 08:05
    Bike
    ZX9R, KLF300 waverunner tower :)
    Location
    Auckland----------south
    Posts
    350
    Quite a bit different piston by the looks of it, this piston has two windows on in inlet side and two holes drilled either side of the Gudgeon pins on both sides...

    what CC is that kit
    Matty C

    Have you taken your bike over any sweet jumps?

  7. #7
    Join Date
    30th October 2005 - 20:07
    Bike
    ZPF Rep, GP3 Rep, B2 (alloy B1)
    Location
    Wellington
    Posts
    211
    I see, yeah you can't actually see the window in the piston, but it is quite large. The kit is a definate 49cc, we have measured the barrell. Sorry I meant fibreglass reeds not carbon fibre.

  8. #8
    Join Date
    12th February 2004 - 10:29
    Bike
    bucket FZR/MB100
    Location
    Henderson, Waitakere
    Posts
    4,194
    Even with high crankcase compression, which it won't be especially if it has a crank anything like the one in the picture, the reeds shouldn't be a problem. The only time I've had problems with steel reeds is when there is something wrong with the reed valve cage or how it was assembled. Every time, I lost little 'chips' off the end of the reeds and they developed cracks running back along the length of the reed. Check to make sure the reed is fully and evenly supported when in the closed position and that it has some support in the fully open position.

  9. #9
    Join Date
    30th October 2005 - 20:07
    Bike
    ZPF Rep, GP3 Rep, B2 (alloy B1)
    Location
    Wellington
    Posts
    211
    Yeah you don't want them too loose. You want them loose enough to open up with a little pressure but not so loose that they just flap around.

  10. #10
    Join Date
    12th February 2004 - 10:29
    Bike
    bucket FZR/MB100
    Location
    Henderson, Waitakere
    Posts
    4,194
    With the revs those things seem to pull you would need stiff petals and on the short side as well to get the resonant frequency up. Loose doesn't come into it. Try making some out of say 2L ice cream lid. It will only rev to about 1500rpm and won't accept throttle.

  11. #11
    Join Date
    7th September 2005 - 08:05
    Bike
    ZX9R, KLF300 waverunner tower :)
    Location
    Auckland----------south
    Posts
    350
    we gonna try the homemade fibreglass ones and see how they go, My mate tried a different carb (off a xr50) and it seems to be quite good, a lot more tuneable, high and low end mixture, bit boggy down low, but revs like a banshee
    Matty C

    Have you taken your bike over any sweet jumps?

  12. #12
    Join Date
    30th October 2005 - 20:07
    Bike
    ZPF Rep, GP3 Rep, B2 (alloy B1)
    Location
    Wellington
    Posts
    211
    What does it actually rev to?

  13. #13
    Join Date
    7th September 2005 - 08:05
    Bike
    ZX9R, KLF300 waverunner tower :)
    Location
    Auckland----------south
    Posts
    350
    fuck knows at this stage , havent got a rev counter, thats in the pipeline
    Matty C

    Have you taken your bike over any sweet jumps?

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •