(1978 k)Z650 Clamp on air filters

Discussion in 'UK Motorcycles' started by martinski, Jan 6, 2004.

  1. martinski

    martinski Guest

    I bought a set of 39mm clamp on air filters (EMGO not K&N's) which arrived
    today and they look the dogs. I've been advised from group members who seem
    to know a shed load more about bikes than i do that i've made a big mistage
    buying these. New jets and the possibility of my carb bank snapping off
    their mount being just two worrying side effects of fitting these bastards.
    Has anyone here fitted a set to their pride and joy? If so, please advise if
    the associated hassle was worth the effort or whether i should, as others
    have strongly recommended, stick with the standard airbox set-up.
    It's okay Lozzo.....I won't be hurt if you decide not to contribute to this
    one :)
    martinski, Jan 6, 2004
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  2. martinski

    Steve Parry Guest

    Personal preference I guess but I cannot stand the bloody things. The
    hassles involved with jetting, they can be troublesome if the get wet
    etc .. and at the end of the day the standard system works well enough.

    Steve Parry


    Steve Parry, Jan 6, 2004
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  3. martinski

    Lozzo Guest

    martinski said...
    I fitted individual K+N filters to a Suzuki GSX750EFE a few years back
    [1], I fitted a Ledar air corrector kit, which included the correct jets
    at the same time. I'd say the filters were a total and expensive waste
    of time. The power delivery was completely screwed up along with the
    fuel consumption, despite plug chops showing that the mixture was
    correct throughout the rev range. It was certainly no faster and bogged
    down, like a highly tuned 2-stroke in too high a gear, before the power
    came in. As well as that, when it rained the bike ran like a total and
    utter sack of shit. I'd oiled the filters as per K+N's instructions,
    fitted a shield between the seat and tank to stop rain water flowing
    down and onto the top of the filters, but it always ran like an
    asthmatic 20 year old, half dead labrador when it rained.

    Things got no better when I fitted the Harris F1 4-1 full system with
    optional and swoppable race baffle either, in fact they got worse and I
    was advised by TTS Tuning to remove the filters and go back to the
    standard air box. This was very difficult, mainly because I'd chopped
    the airbox into four parts with a bolster chisel when I fitted the
    filters, to save me the bother of removing the complete rear suspension
    to get it out. I sourced another airbox cheaply[2] from a breakers yard
    and spent a full day fitting it. Left the air corrector kit in to
    compensate for the Harris pipe and it ran perfectly...until I missed 4th
    gear and got the *other neutral* at Santa Pod and smashed the head,
    valves and pistons. Oh well, gave me an excuse to have a Yoshimura 810cc
    conversion done.

    Get rid of them on e-bay and stick with the stock airbox, seriously.
    You'll regret fitting those filters, especially if you are a little
    lacking in mechanical knowledge.

    [1] Ok, when God was a teenager then.
    [2] Who ever buys air-boxes, they're dirt cheap, same goes for swing
    arms and rear mudguards
    Lozzo, Jan 6, 2004
  4. martinski

    Sean Guest

    martinski let forth with a mighty belch and uttered :
    True, in a kind of retro way.

    I've been advised from group members who
    Yup. Heed them.

    New jets and the possibility of my carb bank
    The air box provides support at the rear of the carb. Standard thing round
    my way was to nick some meccano<sp> or similar to make a support strut.

    being just two worrying side effects of fitting
    Yes, they lasted about two weeks before the airbox was refitted. I left the
    ( compulsory ) Ledar ( think Dynojet ) kit on though.

    Was it **** as like. It was an expensive waste of time. If I wanted to wreck
    the carburation at the bottom end, then it was worth it.

    Oh yeah, then when it rains......

    or whether
    Yup, especially on what is rapidly becoming, if it isn't already, a
    desirable classic.

    It's okay Lozzo.....I won't be hurt if you decide not to
    Sean, Jan 6, 2004
  5. martinski

    Hog Guest

    Don't forget getting the right length of inlet stub to match the exhaust
    system, valve/port timing etc.

    I had them off my RD250<baits hook>DX pronto. Though with reed valves I
    guess the inlet manifold length may be moot.
    Hog, Jan 6, 2004
  6. martinski

    Lozzo Guest

    Champ said...
    Deffo 'Ledar'. IIRC the company took the first part of its name from
    part of one of the founder's names, the late Leon Moss. You learn these
    things when you've fucked about with tuned 2-strokes for as long as I
    Lozzo, Jan 6, 2004
  7. martinski

    Lozzo Guest

    Hog said...
    Very important is intake stub length, as is the shape and radius of the
    edge of the bellmouth inside the filter.
    No, it really makes a big difference. If you don't fit the Ledar stub
    extenders they run like shit at all revs. I learnt that fitting a stub-
    stack within the K+N on an RD makes a huge difference too. I found out
    about the effects these have when I read about them in Vizard's 'Tuning
    the A-Series Engine', whilst I was tuning a 1971 Cooper S.
    Lozzo, Jan 6, 2004
  8. martinski

    Hog Guest

    That has a certain resonance.

    ps. eBay has been full of RD's in the Bedford area....
    Hog, Jan 6, 2004
  9. martinski

    Lozzo Guest

    Hog said...
    I know, you really don't want to see just how fucking wired I've been
    over the last few days watching the auctins progress.

    While we're talking RDs, Caz bought a 4000 mile old 1981 X plate RD200
    [1] today, seized and fucked motor[2] but absolutely excellent in every
    other respect. Even the chromework inside the mudguards is good and she
    says it looks like it's ever been dropped either. Cost...70 quid. She's
    going to use it to rebuild/restore her wrecked RD125. I gave her the
    full history with the 125 when she took it on, as it's a bike I've known
    from new and I was only the second owner.

    [1] Identical to her 125, metallic burgundy with the LC type stripes and
    not a scratch on any of the paint or anywhere else.
    [2] Been sat for years with no spark plugs in it.
    Lozzo, Jan 6, 2004
  10. martinski

    Hog Guest

    There is a bloke selling a restored RD400C starting price £1850. No bids!
    Hog, Jan 6, 2004
  11. martinski

    Lozzo Guest

    Hog said...
    Over-priced, if it was an E or F then maybe. I reckoned that my 13K
    miles original and unmolested RD250D was only really worth 1200 for
    insurance purposes. I'd doubt any 400, no matter how perfect, will ever
    sell for more than 2 grand.
    Lozzo, Jan 6, 2004
  12. martinski

    flashgorman Guest

    If you're going down this root then you will also need an Alpha four into
    one to guarantee the carburation is completey out.

    Make sure it's one that means you have to remove the centre stand AND also
    blocks access to the sump plug.

    Always carry a screwdriver to keep tightening them down and resign yourself
    to slowly trundling back and, forth looking for the one that just fell off,
    at least once a fortnight. Get a couple of spares.

    And never ride if it's raining, looks like it might rain or has rained in
    the past fortnight.
    flashgorman, Jan 6, 2004
  13. Blimey. Ever tried buying at least two of those items for an old
    Kawasaki triple? ;-))
    The Older Gentleman, Jan 7, 2004
  14. Died when some twat failed to hitch a trailer properly to his car, IIRC.
    The Older Gentleman, Jan 7, 2004
  15. Alfa. And spelled that way, presumably, to warn you it was absolute
    Heh. Excellent.

    Don't forget the bottle of air filter oil, for regular re-applications.
    The Older Gentleman, Jan 7, 2004
  16. martinski

    Salad Dodger Guest

    Blimey. Ever tried buying at least two of those items for an old
    Kawasaki triple? ;-))[/QUOTE]

    If you think the airboxes are like rocking horse shit, try getting a
    rubber boot to connect one to the carbs.

    | ___ Salad Dodger
    |/ \
    _/_____\_ GL1500SEV/CBR1100XXX/KH500A8/TS250C
    |_\_____/_| ..62661../..14297.../..3157./.19406
    (>|_|_|<) TPPFATUICG#7 DIAABTCOD#9 YTC#4 PM#5
    |__|_|__| BOTAFOT #70 BOTAFOF #09 two#11 WG*
    \ |^| / IbW#0 & KotIbW# BotTOS#6 GP#4
    \|^|/ ANORAK#17
    Salad Dodger, Jan 7, 2004
  17. martinski

    Champ Guest

    So true :)
    Champ, Jan 7, 2004
  18. martinski

    Nigel Eaton Guest

    Using the patented Mavis Beacon "Hunt&Peck" Technique, Champ
    #Funny how it seems
    Nigel Eaton, Jan 7, 2004
  19. martinski

    Steve Parry Guest

    ooohh thats like a whiz back to the late 70's early 80's ..one minor
    correction the exhaust system referred to was an Alfa 4-1 from thos
    "wonderful" guys at Micron [1] if I recall correctly ;o)

    [1] manufacturers of equally shite but well marketed 2 stroke systems

    Steve Parry


    Steve Parry, Jan 7, 2004
  20. martinski

    flashgorman Guest

    flashgorman, Jan 7, 2004
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