Kawasaki F7 175cc Thread

Discussion in '2 smokers' started by the_doc, Mar 4, 2014.

  1. SoyBoySigh

    SoyBoySigh Constructive-Critic

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    I've always felt the '70s Japanese too-smoke single-cylinder DIRT-bikes, need to ALL be re-built as ROAD RACERS, in the vein of an OSSA or BULTACO TSS etc.

    Check out the Honda Elsinore based MT125R to get an idea of what I'm talking about. The MT125R doesn't just beg for a follow-on "MT250R" but it's got me thinking about the biggest versions of Honda two-stroke singles, which were what? Something like 500cc or 650cc on some type of XL650L or whatever it was called? And there were BIG-BORE kits for that stuff, too - Wasn't there?

    Any problems with the chassis and just stuff 'em into the smaller SOHC-4 frames, simplifying the whole question of street registration.

    And if the Honda drum hubs aren't up to snuff? Skip straight past the wire-spoke conversion of the CBX550F Comstar "inboard disc" fake drum brakes aka FAUX-LEADING-SHOE as I've coined 'em - I've been tinkering with a GL1500 based version, though it's stalled in it's tracks and I'm now looking to the PC800 Pacifica for IT'S front wheel hub/core. Only 230mm rotors on the CBX550F whereas GL1500 was dual 296mm with potential for 316mm upgrade using GL1500SE rear discs, while PC800 is only 276mm but upgrades to 296mm with USA-spec CB1100F rear discs. That type of shit would stop ANYTHING, and they'll be a very strong & stiff version of a wire-spoke wheel due to their larger diameter 'spoke flange'. Though it's not truly a "spoke flange" per se. As much as for strength reasons as clearing between the rotors & calipers etc, we'd want straight-pull "NAIL" spokes - That would be most sensible in the GL1500 or PC800 version, IMHO. That way you're not adding any additional weight as in the case of the CBX550F version's ridiculous steel spoke flanges & assembly bolts etc, instead we're talking about wheel cores which are deceptively lightweight, they're just a thin balloon skin of alloy, in fact I'm more worried that it'll be too FLIMSY, rather than too heavy. These "Faux-Leading-Shoe" fake drums are powerful enough to stop ANYTHING. CBX or DOHC-4 based "Hailwood Replica" Yeah, now you'd finally have a brake that's as good or better than the best OEM versions, but you'd get the retro-fried look as well.

    Picture the Jap too-smoke single ROAD RACERS though. Even if you're gonna use first-gen disc brakes for a more mid-'70s aesthetic, we're talking about the PE350 & IT400 etc. Wasn't there an IT475 or thereabouts?

    There are a ton of these bikes rotting away in sheds all for the lack of NOS bits to restore 'em with. The dirt-bike kids regard 'em as JUNK when there's nothing left but an engine & frame. Well that's all we'd WANT for what I'M talking about here.

    Just picture it. Mull the idea over in your head.

    Mmmmmmm......


    -Sigh.
  2. SoyBoySigh

    SoyBoySigh Constructive-Critic

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    Here are some pics for inspiration.
    Honda MT125 Elsinore
    [​IMG]

    Vs MT125R factory club racer / road racer
    [​IMG]
    http://raresportbikesforsale.com/wp-content/uploads/2010/12/MT125R_6.jpg


    Bultaco dirt-bike is hideous
    [​IMG]

    Bultaco TSS a PROPER stink-wheels:
    [​IMG]
    (For once, thanks to the 2LS/4LS drum hub, a leading-axle fork looks AWESOME!)

    Even in liquid-cooled form, the Bultaco TSS is the proper deal.
    [​IMG]

    ASPES YUMA
    ASPES

    [​IMG]

    This last one gives me ideas about parts of the GPZ305 and or AR50/AR80, for the properly lightweight versions of Kawasaki's traditionally very heavy cast wheels, the 7-spoke Morris clones from the KZ series for instance. (I've found a decent use for 'em around the house - [​IMG]
    S'pose if I had enough of them I might go for the vintage '70s-'80s "Ranch" architectural theme, where you wrap a fence of old wagon wheels around your bungalo - Anybody remember THAT nonsense?
    [​IMG]
    Yeah, could very well be that the cast bike wheels had an even greater influence on our larger culture as a whole.....

    Just DON'T get any ideas that THESE were the types of Kawasaki CAST wheels which I am suggesting here.

    THIS is what all I'm meaning to imply:
    [​IMG]

    Cheaper & easier to find in this version:
    [​IMG]

    Though it's tempting 'cause of the slightly wider rims & dual-disc front end, I think we're ALREADY getting a bit too heavy for what we're talking about here. You WOULD want to beef up the specifications for a real beater of a curb-bashing street-bike version of this one. The AR50 version, perhaps better suited for the track-only version of the same thing?

    To tell you the truth though, the WIRE-SPOKE thing is already one of the strengths these lil' bikes have going for 'em. That front hub is far too small, but at least the rear end is already lined up with the chain-line etc. Of course, just as with the AR50 vs GPZ305 example, even with alloy rims for wire-spokes, they're not ALL made for racing, some of 'em are probably heavier than their chromed steel alternatives. Even within a brand, you'll wanna watch out for the PROFILE type - For instance Akront TR being far superior to the Akront TC, which are thicker & can take more of a beating. Just sayin' - A build like this, you'd want to scrimp & save on every last ounce! Both in terms of rim wall thickness, whether you can seal 'em as tubeless with aquarium silicone (presence or absence of bead-retention ridges) what the spoke-count is, just how wide of a tire you absolutely need vs how relaxed the tire is within a given width of rim vs THAT extra weight - These wheels would have to be REALLY well thought out!

    The bike's advantage over other too-smoke racers, is in it's lighter weight engine & spare simple frame. You'd wanna beef up some stuff where necessary, but without going over-kill on 'em. 'Cause that one strength of weight must be kept throughout the whole build otherwise it'd fall flat & just be an average commuter. So keeping in mind the 125cc-175cc racing singles rather than the 350cc displacement and it's contemporaries within that class, & THEIR specification.....

    Yeah, even so. We'd want to keep the wire-spokes 'cause above all else I'd really rather see some DRUM brakes on these babies. Though come to think of it the cast wheels with a drum FRONT hub, are a hell of a lot more cool than the cast wheels with triple disc brakes. Can I get an AMEN? I've seen some cool stuff done where rear wheels with drums were re-purposed as a front wheel. Very interesting stuff especially when it's done with two 16" rear CRUISER-esque type mag wheels. Albeit a tad bit heavy.

    And hey SPEAKING of which - if ya'll are of the mind that you picture this as a SUPER-MOTO incarnation, that you're not INTO the whole "skinny rims" thing - Well ya'll need to check out my yapping about my daughter's "KZ440LOL" project, wherein the 4LS Suzuki hub is wrapped up in a 3.0x16" Borrani rim - classic fare for vintage SIDE-HACK racing, or as a rear rim on Harley CHOPPERS - Well I'm using 'em with low-profile radial tires for the relatively new MAXI-SCOOTER segment, in 110/70-16 & 140/70-16, with an all NOS belt-drive system & 39mm fork from CB900F, etc etc. The thing is all of these parts are the same age or older than this 1980 KZ440LTD donor bike.

    Which is why I've dubbed it, variously ... at times, as a:

    PROTO-MOTO!!! Heh-heh.

    See, there are a TON of cheap rims to grab which are probably even MORE appropriate for a smaller build, being that the KZ440LOL tire sizes are even more appropriate for the bike's size, speed, weight, load-bearing index, etc etc -

    Well for these OTHER, more SPORTY versions of the same concept? I'd suggest any random 36-spoke drums ideally in the 200mm front, 180mm rear sizes - IF you've got right-hand-side chain final-drive? Then you get a 2LS drum on the REAR, too - From the CB72/CB77 Hawk/SuperHawk etc -

    While the RIMS as such, from "Mike's XS" and very affordable especially if you grab the crazy 48-spoke versions and lace some really wild spoke patterns with that - They've got stuff like 2.15x16" for the front & 2.50x16" - IIRC there was at one time also a 2.75x16" for that model, though if you're REALLY committed to the whole MAXI-SCOOTER tire, "CLOWN SHOES LOOK" - there are 3.0x15" & 2.75x15" rims from the whole mid-'80s "POWER-CRUISER" segment, and for this diameter of Maxi-Scooter tires you've still got some DUAL-COMPOUND RADIALS available! Nuts.

    Absolutely well worth some super-wide chain-lines, only the type of rubber I'm talking about for the WM3/WM4 16"-ers would be something like 80/70-16 through 120/70-16 max - Inclusive mind you. So if your chain clears a KNOBBIE tire? You're gonna be fine without an extra-wide swing-arm & off-set sprockets etc etc.
  3. SoyBoySigh

    SoyBoySigh Constructive-Critic

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    Kawa F9 Big-Horn based road-racer.

    Saw a site last week (the last time I was obsessed with this whole Kawa F-series ROAD-bike idea) I dunno where the link is now, but they'll build the F9 engine as a road-race specific re-design, boosting power ridiculously - they've got a full service with re-shaped combustion chambers etc etc
  4. WDesign

    WDesign Adventurer

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    I honestly feel like these old bikes need to be restored and just enjoyed. I absolutely love mine, such a feeling of raw biking, biking as it was supposed to be, a time when you need skill but you didn't have to be an expert.
  5. SoyBoySigh

    SoyBoySigh Constructive-Critic

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    Oh come ON! First of all, let's forget the 1970s attitude of ripping up the endangered cryptobiotic soils & making a general mess of what few remaining natural habitats still persist between intersections of our encroaching suburban morass. Make a ring-ding-ding stink of blue smoke WITHIN the big schitty. Run some moguls & jumps & other obstacles ON the pavement. If you've gotta get some air on it, haul it down to the local SKATEBOARD park!

    And while we're forgetting our antiquated preconceptions - Forget about the lure of the multi-cylinder version of such racers. HEREIN there is opportunity to squeeze 350cc displacement in what might otherwise be a 125cc-175cc build! I'm under no illusions about the F9 Bighorn competing with even an S-series 350, but when you picture it all built as a proper LIGHTWEIGHT, and you throw the leg of a truly spindly teenager or perhaps some stunted rickets-afflicted & starved old man who's nevertheless somehow avoided the Type-2 Diabetes epidemic - which is to say an all-in jockey weight of 120lbs-140lbs MAX - It's starting to seem like a dream-bike.

    Or perhaps to set it up as a substitute for a 49cc MOPED for the likes of my own self?

    Wouldn't it be one hell of an ADVENTURE RIDE, say - keeping up with freeway & highway traffic while negotiating the vast CONCRETE JUNGLE, crossing continents ON the beaten path -

    That is, if one were travelling on a bike such as THESE ???

    Just look at the pictures!

    [​IMG]
    JCool likes this.
  6. elgringo-inaz

    elgringo-inaz El Gringo

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    Uncle bought this new in '72. Got her running sweet. Have not tried to get her up to 75mph yet (as touted) until I replace the very old front tire. But she sure feels like she will go fast.
    upload_2018-3-17_12-57-8.png
  7. sjc56

    sjc56 Long timer

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    Very nice! Mine tops out at 62, not sure I really want to go much faster then that!
  8. sjc56

    sjc56 Long timer

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    Well something went in the gearbox today. Getting the bike ready for my annual Tiddler ride, I was out for test ride going through the gears and it starts make a loud rattle. I shut it down and was able topcoats back to my house in neutral. Makes the sound just rolling it and seems to be in gear when rolling backward in neutral and lots of shiny bits in the oil.
  9. Westcoasthumpin

    Westcoasthumpin Been here awhile

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    That sucks! :muutt:doh
  10. RockyRue

    RockyRue Long timer

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    This week going to:
    Replace petcock with manual one
    Rebuild carb
    Change transmission oil
    Brake shoes
    Rebuild forks
    Getting ready for Vintage Dual Sport here in PNW :)
    Redclayrider and Westcoasthumpin like this.
  11. sjc56

    sjc56 Long timer

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    Before I trashed the gearbox (i think) I block off the gas drain on the front of the crankcase after reading that this is a likely air leak and for the first time the bike would idle at around 1000 where before had to keep it up around 1500 so it wouldn't die. I just put some JB weld where the drain hose comes out.
  12. paul86

    paul86 n00b

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    Looking for a working link to an online repair manual. Really just need the electrical diagram for a 1975 F7 175. I was given a bike with a rats nest of wires and once I get that resolved, I think it will end up being a nice bike.
  13. sjc56

    sjc56 Long timer

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    Just Google 1975 kawasaki F7 wiring
  14. paul86

    paul86 n00b

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    Took some photos of what I'm working with. Hope they are clear enough. So far, if I'm reading the wiring diagram correctly, it appears the wires that aren't connected just go to the horn and lights. Problem is, I'm not getting a spark at all when I kick it over. New battery, key turned on, in neutral (light is on). What else needs to happen?



    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
  15. sjc56

    sjc56 Long timer

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    Trying to find out my problems, Cultch looks fine, I did find a metal chip so I think I'll try my other motor, hopefully that works, I'll swap over the new DSCF0927.JPG parts on put on this one
  16. AtLarge

    AtLarge Been here awhile

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    No spark means you are going to need the DMM and start testing for continuity all along the harness. Firstly, see if your getting power to the coil. All contacts will be suspect so start pulling, cleaning, and testing. As for the chip I would have to see it before passing a concern. Seems like there is always a few chunks left over from the machining process or wear. Not that abnormal.
  17. sjc56

    sjc56 Long timer

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    I need a little help here, I replaced the motor on my 72 F7 175 and when hooking up the carb can't figure out where the hose on the carb behind the gas line for the oil injection goes, it routes through the air intake and out the case through a grommet but how does it hook up to the pump? I'm having a senior moment here. Clym IMG_0017.JPG er is no help.
  18. RockyRue

    RockyRue Long timer

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    The 2nd line on the carb is for the vacuum actuated petcock.
    No oil involved
    If you have replaced he vacuum petcock with an aftermarket standard, just put a bolt in it
    AtLarge likes this.
  19. AtLarge

    AtLarge Been here awhile

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    True and put a rubber or plastic cap (like a thread protector from the hardware store) on the nipple of the carb. That's what I did. I went aftermarket on the petcock too. When I get the rest of the bike done I will probably revert back to the OE petcock when I'm confident it's working properly. Those vacuum types can be problematic.
  20. sjc56

    sjc56 Long timer

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    I thought the third fitting, Which you can see I plugged was for the vacuum line? The clear line I thought was for the bottom end oiling.
    Which is where if I remember, is where the old petcock vacuum line went to.