f7 175 bogs down

Discussion in '2 smokers' started by sjc56, May 17, 2012.

  1. sjc56

    sjc56 Long timer

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    [​IMG][/url]
    F7 175 by steven_j_cote, on Flickr[/IMG]

    After almost two years I finally got the little bike legal and it runs like crap out on the road, it bogs down at 4K and struggles to get to 60 mph. Plug looks rich, its a dark gray but no deposits on it after a 15 mile ride my , I check it with my color tune and the flame is a nice yellow , The late PO ran it without the baffle so I am thinking he richen it up so I'm going to drop the needle and see what that does. Bike has only 7K on it so I would think the motor is okay. My old craftsman compression gage broke so I haven't check it.
    I'm doing a tiddler ride next weekend, mostly Italian bikes, so I need to up hold the reputation of the Japanese bikes. Last year the only bike that crapped out was a Honda.
    #1
  2. sjc56

    sjc56 Long timer

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    I just read the KE100 thread very similar. I have a new baffle and air filter so I don't have to look there.
    #2
  3. sjc56

    sjc56 Long timer

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    Problem resolved it was the O ring going in to the float bowl the one I had was to small.

    If your bike won't run at full throttle, or seems sluggish, the o-ring is bad in the float bowl. This o-ring seals the main jet passage to the bottom of carb. Your main jet is in the float bowl, looks like drain plug from outside. If there is no resistance when putting bowl up to bottom of carb, the o-ring is shot.

    Thanks to who ever posted this on Motorcyclesurvey.com.

    I would have never found this.
    #3
  4. Euromad

    Euromad Been here awhile

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    Thanks for the tip. Just got mine running too.
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  5. sjc56

    sjc56 Long timer

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    I f I had not found the info on the o ring I would have given up since I had already replaced it with an O ring from another carb kit I had and but it seems was to small for a good seal. Google is good!
    #5
  6. cgk64

    cgk64 Adventurer

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    I've got a 71 175 F-7, that wouldn't idle ended up being the rubber intake boot. now I need an air filter and a rear tire and I'm ready to go.I bought mine from the original owner, I was able to keep the original plate. Do you have the original air filter, or did you go with something else.
    #6
  7. lake_harley

    lake_harley Been here awhile

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    cgk64....do you need the entire airbox or just the filter element? I have a nice airbox (no filter element though) from a '74 or '75, and probably a useable rubber "elbow" if you need either. PM me if you do.

    I have lots of other parts as well on the F-7 parts bike that came with two others.

    Lynn
    #7
  8. cgk64

    cgk64 Adventurer

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    I need the foam. Just got it back from the shop yesterday and they replaced the rubber intake boot, ran good at the shop ,get it home now it won't idle again.I need to find a good 2-stroke mechanic in my area.
    #8
  9. sjc56

    sjc56 Long timer

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    Lynn, on your parts bikes you wouldn't happen to have a set of turn signals you could part with.?
    #9
  10. sjc56

    sjc56 Long timer

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    For my filter I just bought a sheet of uni foam cut it to size and warped it around the mesh filter holder.
    #10
  11. Euromad

    Euromad Been here awhile

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    #11
  12. lake_harley

    lake_harley Been here awhile

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    Sorry, no turn signals. In fact I'm a set short to finish the #2 bike of the three 175s I bought. I see Euromad posted about some he has though.

    Lynn
    #12
  13. sjc56

    sjc56 Long timer

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    I just sent him an Email.
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  14. cgk64

    cgk64 Adventurer

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    What kind of glue did you use, or how did you attach the foam.
    #14
  15. sjc56

    sjc56 Long timer

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    I cut a pice A little wide so it would seal the on ends of the air box, then I glued the ends together with contact cement. It has held for a year so far.
    #15
  16. sjc56

    sjc56 Long timer

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    I have put about 40 miles on it and man this thing is geared low, you can get away starting in second and at 45 in fifth you are doing about 5K. And brakes, back tire locks pretty easy and I think there is a front. Gets to 55 okay then it is a slog to 60 motor sounds okay. At 7K on it could it us a set of rings?
    #16
  17. cgk64

    cgk64 Adventurer

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    Thanks for the info.
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  18. cgk64

    cgk64 Adventurer

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    Well I can tell that Its been a long time since I've been riding. found out why the bike was not running right, I should of checked the fuel level in the tank, switched it from ON to RES and now it run good.I also might have a problem with the automatic fuel cock. I'll take it for a spin tomorrow and see how it goes. So the mechanic did his job right.
    #18
  19. JeffS77

    JeffS77 cheap bastard

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    moral of the story...always check the obvious first.. :evil

    its cool we have all done something similar at some point
    #19
  20. sjc56

    sjc56 Long timer

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    I did the 80 mile tiddler tour yesterday, what a fun day buzzing the back roads of CT with old Hondas,Jawa's, Moto Guzzi's
    and one ZX14 that followed us out of curiosity.
    The F7 ran okay, seems to carburate okay, not much power under 4 grand, first is so low I just use it to get rolling them up to second. I seem to be leaking oil from the shifter shaft seal. I would say I am getting around 45 mpg about, what I get with my Buell Uly.
    #20