Restarting my project VF500F from 2016

Discussion in '1st & 2nd Generation 1983-1989' started by Hellapet, Apr 18, 2021.

  1. Hellapet

    Hellapet New Member

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    Thanks for the link, I'm starting to get it now. I had thought that the sealing surface for the drive sprocket was what is in the way but I realize now there is a whole lip around the seal that it is "bottoming out" against, from the inside. Thanks Honda. I like your idea but I think "coin slot" is a better name.
    Dang, I looked for info on how to index the boots but couldn't find anything, all I saw was that my boots had "CARB" molded into the top side. If anyone has pictures or more info on how to orient the boots that would be great.
    Regarding taking the carbs back out, I think I'm gonna have to send them to a rebuilder. I just have no clue what I'm doing on a v4 carb setup and don't have faith in myself to do it right on the first try. The issue really is that the bike will stall straight away if I don't keep at least some amount of choke on. It also takes forever to warm up. I guess the first thing I should check is that the choke cable is adjusted properly.

    I just checked that the rotors are good with the pencil trick. They seem fine, though there is a little scuff on the caliper where it hit the pavement. Might be a very small bend that is just barely making contact. I have to imagine there are some thousandths of play in the front wheel bearings. It's also possible the sound is coming from the back end.
    Thanks everyone for all the help, I'd really be lost without this forum.
     
  2. Captain 80s

    Captain 80s Member

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    insulatorcarb.jpg

    Carb side goes on the, well, carb side. Up. See that notch in the ridge on the top of the picture? On the rear head those will be oriented to the rear, and on the front towards the front of the bike. They correspond with a casting on the carbs, you'll see what I mean.
     
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  3. Captain 80s

    Captain 80s Member

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    If you read one of the many tutorials on how to properly clean V4 carbs, you can do it yourself. It's just everybody assumes their carbs are fine, or they can't do it cuz it's too hard. It's not hard, just tedious, and requires a clean dedicated workspace that will not be disturbed if left unattended.

    Now time is another constraint that some people have. I get that.

    Send them away and they will be awesome. But if the bike ever gets parked without being stored properly (again), you will not have the skill set to correct the problem (again).
     
  4. Hellapet

    Hellapet New Member

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    I wonder if I can correct the rotation of the carb boots just by spinning them with the clamps loose. If not it's not such a big deal to get them off and back on again. It will be a good opportunity to snug up those breather hoses that I just loosely popped on when putting the bike back together.
    I was just looking through the Clymer manual and realized a couple things: these carbs still have the plugs on over the pilot screws. I guess they may have had the bowls opened before I got to them, but wouldn't that mean they've never been rebuilt? The other thing I realized is that I never touched the idle speed screw when I put them back on. So I just got the engine up to temp on a ride and had a go at adjusting the screw, and there is no more stalling when hot, even with the choke all the way off. I will see if the bike wants to start cold but that will have to be Monday. I'm going to Pittsburgh for the Vintage Grand Prix tomorrow. Here's a pic from the ride to my folks'
    [​IMG]
    Next week will be looking at that, the boots and the cooling system. I noticed today that the temp gauge actually went down from dead center to slightly cold when I got up to speed after warmup. I wonder if that's normal or if the thermostat is stuck. I also never heard the fan kick on, I'm gonna do some tests on that too.
     
  5. Captain 80s

    Captain 80s Member

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    TAKE THE CARBS OFF AND VERIFY SOME THINGS THE RIGHT WAY.

    Why all of the short cuts? You know how much more time you're wasting instead of just doing a couple things while they're out ????
     
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  6. Captain 80s

    Captain 80s Member

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    Air flow greatly affects the temp on the 500s. Not saying your thermostat is fine, but what you describe is normal. Fan won't kick on until the needle is up pretty close to "HOT".

    Glad you got ride some miles.
     
  7. Hellapet

    Hellapet New Member

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    I did give them a good cleaning when I had them out, but I didn't take them off the "plenum" or whatever you might call the aluminum piece the airbox mates to. That means I didn't take the diaphragms out but I'm not sure what else is up there on the top part of the carb. I made sure to clean all the holes in all the jets with a piece of guitar string, and blew carb cleaner through any passages I could access. I don't know if there is more that I could unclog without an ultrasonic cleaner anyway, which is why I didn't do a full rebuild. For what it's worth, the bike is running great in terms of engine performance. I just don't want to hurt it.
     
  8. Captain 80s

    Captain 80s Member

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    I get it. But a "good cleaning" and not removing the caps and fuel screws does not compute. No need to remove the plenum to do a proper clean either. But you will probably end up needing to do it at some point, your fuel crossover tube o-rings are going to fail soon likely. And did you replace the float bowl o-rings while you had them out? How bout a bench synch? It's actually really easy.

    Sounds like you're doing ok once you discovered the idle screw. :)
     
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  9. Diving Pete

    Diving Pete Member

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    It is possible if only one not keyed correctly - However, BEFORE you do this - whilst engine is running normally, spray wd40 at the inlet rubbers & listen for engine changes. - you are checking for a air leak. - If its not then leave alone until you need to.

    That will only help - get the engine at the correct idle before doing above.

    Normal - stop trying to fix things that are not broke - lol
     
  10. Hellapet

    Hellapet New Member

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    I'm going to try really hard to follow this advice but I make no promises. I did spray the boots with starter fluid to check for leaks and got nothing so I think that's fine, but it's nice to know a) how to put them on right the next time I get a chance and b) it's probably perfectly fine for now.
    I'm still going to at least confirm the fan kicks on and there are two wires leaving the radiator-mounted sensor harness that have been snipped and I want to make sure everything is at least shielded properly in there.
     
  11. Captain 80s

    Captain 80s Member

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    Did you repair the wires?
     
  12. Hellapet

    Hellapet New Member

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    I just discovered them recently and they look to have been added at some point then cut off. I've read there are supposed to only be two wires to that sensor, correct? Cause I think there are four if you count the two cut wires.
     
  13. Captain 80s

    Captain 80s Member

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    What? The sensor installed in your radiator has how many posts in it? 1 or 2?

    I think somebody installed, or attempted to install, a switch to turn the fan on manually.
     
  14. Hellapet

    Hellapet New Member

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    I think you're right, but at some point someone cut the switch out and left those wires. I'll take a close look on Monday.
     
  15. Hellapet

    Hellapet New Member

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    Got a few minutes to work on the bike yesterday. The clipped wires were in fact just inserted into the terminals for the radiator sensor. Someone did a bad job then undid the job without simply unwrapping the wires and removing them.
    [​IMG] [​IMG]
    Job done, easy enough. I tested that the fan runs when I short these two and it does. However, it was in the 90s yesterday and when I parked the bike and left it running to open the garage door, the needle climbed to about two thirds towards hot very quickly and the fan never kicked on. That may be normal, not sure.
     
  16. Diving Pete

    Diving Pete Member

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    So now that may explain the extra wires - so that may mean that the guy before you used a switch to turn the fan on. You can test the fan sender unit fairly easily & I would suggest that's the next path. However, installing a manual switch may be a sensible precaution anyway.
     
  17. Captain 80s

    Captain 80s Member

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    The fan on a 500 with the stock thermoswitch won't kick until it is surprisingly close to HOT. Install the switch in parallel so if you forget (and the thermoswitch is working) it will still kick on.
     
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