Help me with my VF500!

Discussion in '1st & 2nd Generation 1983-1989' started by tjwor, Feb 28, 2008.

  1. Fizz

    Fizz New Member

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    I know, I'm just saying you can't expect to move the bike a few feet and let out the clutch and expect to bump start it like he described he tried.

    I probably have more difficulty bump starting a bike than most people though; being 5'8 and 130 doesn't help.
     
  2. Fizz

    Fizz New Member

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    Isn't that what I said? :tongue:
     
  3. tjwor

    tjwor New Member

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    Well, I hooked up the vacuum line to the petcock, and the bike did slightly better, this time reving up to about 8K RPM's max... Any more ideas? I might take the petcock apart tomorrow and see if anything looks amiss...
     
  4. Pcohen

    Pcohen New Member

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    i would replace the filter and the lines too while your checking out your petcock. it is most likely a fuel flow issue not a timing issue or anything with the cams. The timing isn't adjustable and if you got the cam gear one tooth off you would definitely know because it would run like crap and tick real loud.

    check your gas tank vent and make sure your carbs are opening properly and are synchronized! check your air filter for massive gunk build up as well and make sure nothing is blocking the air intake
     
  5. masonv45

    masonv45 New Member

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    See if you can fabricate an external gas tank and hook it directly up to your carbs. By bypassing the petcock, you can determine which component is at fault.
     
  6. tjwor

    tjwor New Member

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    We have progress, just not quite enough...

    I stripped the petcock, cutting the diaphrams and such as jamie's how to... the bike seemed to have response up to 8K rpm's, and didn't act like before. So I feel like it is getting the fuel it needs...

    Next thing, the bike is very slow to get the rpm's down after reving it up. A slight turn of the throttle makes it go to 5K and very slowly return to 1.5K (at which point I have to rev it up again or it will die soon...)

    Now, I did a bench sync on the carbs before putting them in, but how am I supposed to do a regular sync on carbs if I can't get them to idle at all...

    Also, what would cause the rpm's to be so slow to return?

    Thanks again for help, hopefully we'll get this done soon!
     
  7. JamieDaugherty

    JamieDaugherty New Member

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    It's normal for them to be a little slow to return to idle. A bench sync is not going to be enough, you need to get a set of sync gauges and the special right angle screwdriver and dial them in properly or take it to a shop and have it done. That is just to start with, my guess is that you have something wrong inside the carbs. Carbs suck!
     
  8. tjwor

    tjwor New Member

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    my main problem is that I don't know how to sync the carbs when I can't get the bike to idle... how do you go about this? can you sync them with the choke on?

    Also, I have access to guages, but am having problems finding 3 more nipples to connect the hoses to my carbs...
     
  9. JamieDaugherty

    JamieDaugherty New Member

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    Can't you bump up the idle screw until will run without blipping the throttle? If not then a sync is the least of your problems!
     
  10. tjwor

    tjwor New Member

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    okay, i have the carb sync guages ordered, and took it out today just for a little spin to check up on things... I have a few questions and need some easy answers I believe...

    1. I started the bike a few days ago so my girlfriend could hear it run, i let it run for 2 or 3 min tops, then turned it off. I was looking around/feeling around on the engine and I noticed that 3/4 of the piston housings were hot, the other one was just mildy warm (getting off to the left of the bike, the rear piston housing was the just warm one) Is this just something to do with the carbs not being synced meaning less air flow to that cylinder?

    2. The bike ran good as long as I didn't let it try to get to idle, except for if you try a hard acceleration it studders and bogs down a little bit. If you do slow accelerations it has no problems at all. So to me it sounds like it is running lean? Thoughts on this?

    3. Valves are noisy, i don't really know what "too noisy" is... The engine was completely rebuilt by an experience mechanic, should I just trust that he followed the books instructions and adjusted the valves right, or figure out how to check them myself?

    4. I have a small leak of what I have decided is clutch fluid. It drips on to the exhaust, I can't see where the leak is coming from, and from the small rides I have not seen any noticeable fall in the top reservoir on the clutch fluid. Is this something I should worry hard about or just keep an eye on it and deal with the slight smoke coming from the exhaust at stop signs?

    5. What type of tool will I need to actually turn the carb screws, I have looked into them a little but, but i'm not sure that i'm even seeing any of the right screws...


    Final question, Should I wait to ride the bike until I finish syncing the carbs, which will be later this week, or am I alright to go on short >5 mile rides now and then until I get around to the carbs?

    Any help is appreciated as always!! Thanks You Guys!


    Edit: Also want to remind everyone/ add, I have aftermarkete Yoshi Pipes and K & N Air Filter, I Have no idea if the PO did anything to correct for these...
     
    Last edited: Jul 20, 2009
  11. JamieDaugherty

    JamieDaugherty New Member

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    1) By 'piston housings', do you mean that you are feeling the side of the cases? If so, then I'd say your assumption is correct, one of the cylinders is completely closed off. Pretty typical for out-of-sync carbs.

    2) It could be either, I wouldn't worry about this until the carbs are sync'd.

    3) The VF500's have noisy cam chains, that might be what you are hearing. If it sounds like a sewing machine that is good, a jackhammer is bad.

    4) That's probably not clutch fluid, it sounds like engine oil coming from the pushrod seal. It's common for those to leak and the fix is not that simple. If it gets too bad you'll have to do something about it. Do some searching for "VF500F pushrod seal leak" and I'm sure you'll find something.

    5) You need a right angle drive screwdriver, another special tool. The screws on the VF500F are really difficult to get to. I've found it easier to adjust them with the engine off then check. Normally you just leave the engine run when setting the sync, but it's such a pain on the 500 and I don't like leaving it sit and idle for that long because it gets hot.

    I hope this helps!
     
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