New (to me) 91 in need of serious help

Discussion in 'Mechanics Garage' started by rogersj3, Apr 30, 2010.

  1. rogersj3

    rogersj3 New Member

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    With a fully charged battery, it will crank over twice and then run out of juice. Same result if jumping off a running car. My plan of attack is as follows:
    1. confirm proper functionality of the fuel pump
    2. confirm the spark plugs are firing
    3. cry a bit about having to buy a starter

    I suspect the fuel pump based on the fact that the carbs were completely frozen - it stands to reason (unfortunately) that the pump would be frozen as well. Beyond that, I'll just have to run down the troubleshooting list in the service manual for "it don't start nohow."

    Don, what would it mean if the engine will crank without the plugs installed?
     
  2. donald branscom

    donald branscom New Member

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    It means it is completely flooded and you cannot compress a fluid. I do not think this will be the case.
    Why don't you test the fuel pump off the bike BEFORE you go and buy one.
     
  3. rogersj3

    rogersj3 New Member

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    Yeah, I assumed thorough testing before purchasing a new pump in step one; here's a quick and dirty video I just shot demonstrating the start up (or lack thereof) sequence: YouTube - VFR won't start :confused:

    What do you think?

    P.S. - I don't recommend mechanicing in a suit on a Sunday afternoon. Just begging for trouble...
     
  4. Badbilly

    Badbilly Official VFRWorld Troll Of The Year!

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    If the engine spins w/o plugs ande all else fails, with some tubing a flaring tool and other miscellaneous hardware you could have a really nifty air compressor that looks like a VFR.
     
  5. donald branscom

    donald branscom New Member

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    RogersJ3,

    Thanks - for the video. Very good idea.
    IT sounds like a dead battery.
    Was that a separate battery? Was it a car battery?
    Were the plugs in or out?


    I wanted to hear a report on a start NOT using the start button on the motorcycle. Do you have a mechanics REMOTE starter switch?

    If it was jumper cables, was the positive right on the starter positive terminal?

    What i would like to see is jumper cable to ground and positive jumper to positive terminal on starter momentarily. NOT through the start switch. Read that again.
    Separate battery. NOT the battery on the motorcycle.
     
  6. rogersj3

    rogersj3 New Member

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    Finally got another chance to work on my bike; report follows:

    Decided to start with the fuel pump. Following the test procedure from the Service Manual was not useful (jump the relay to deliver constant power to pump) because power doesn't appear to be arriving at the pump relay. Checked the fuse and it was okay - did find a blown one, but that was for the horn and turn signals. My multimeter is dead at the moment, going to Radioshack tomorrow to sort that out. Can someone tell me where the ground is located? I'm thinking that there is most likely a correlation between the "sounds like a dead battery" behavior of the starter and the "I'm not getting any juice" behavior of the fuel pump - does anyone have any previous experience fixing this particular issue?

    I'm beginning to suspect that the "Classy Gentleman" who sold me this motorcycle-shaped collection of metal and plastic knew about all this crap...
     
  7. rogersj3

    rogersj3 New Member

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    Multimeter good to go, further test results are interesting. Voltage to the Fuel Cut-Off Relay is good (about 13V, if I'm remembering correctly), and when the relay is jumped (per HSM procedure) the pump does run. Unfortunately, the pump produces zero suction and will have to be replaced. OEM from bikebandit gives a price of $150 and eBay is about $60 - $80 for a used part. Anyone had any problems using parts sourced on eBay?

    Second issue: with the relay not jumped (aka "normal mode") the pump never kicks in at all. The hoses were disconnected from the pump, but other than that the bike was in "I should be running, but I'm not" configuration. Any ideas on that?
     
  8. 750nick

    750nick New Member

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    Just thought I'd add a few things here. First, you can get the full repair manual off of Carlsalter.com for your bike for free. Second, I would use something more on the lines of Seafoam to clean parts on your carburator. The stuff works wonders and can be found at any auto parts store. Third, when you get that machine running and take it for a spin you will not be dissapointed in spending time on it. It is truely a special machine. You came to the right place for advice and the bike is pretty easy to maintain/fix with the body panels off like you have it. Take your time and do it right or do it twice. Good luck, Nick
     
  9. dehning

    dehning New Member

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    Dude, just eliminate the pump and switch to gravity feed (for now at least). It's a standard practice with the early CBR1000's too, and I have to assume they use more fuel than a VFR750
    I did the conversion to my '88 CBR1000 hurricane and it worked great.
     
  10. rogersj3

    rogersj3 New Member

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    Well, I just confirmed what Don seems to have suspected; apparently my starter motor was bad too. "I built it one piece at a time," but it sure is costing me a few dimes. eBay fuel pump arrived, installed and seems to be working properly. I did the "straight from running car battery to starter motor terminal" jump and the motor did not try to turn. The HSM says this indicates a bad motor, so I've ordered a used one on eBay for $61 shipped. One piece at a time indeed.
     
  11. nbogert

    nbogert New Member

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    I'm interested. I'm pretty sure I PMed you, maybe not lol. Do you have any pictures I can see. I'm interested in the L/R fairings cast you have for the 91. Let me know. Thanks.
     
  12. nbogert

    nbogert New Member

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    oh and...I love my 91. It was/is a bit banged up. Had some issues that I fixed, but otherwise the bike is pretty easy to work on, and quite a good time when it's running. Don't lose hope. These guys on here know their stuff. Good luck man.
     
  13. rogersj3

    rogersj3 New Member

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    Okay gentlemen, I'm really starting to get frustrated. Used starter motor arrived today and was installed about an hour ago. Still no joy. Trying to start from the on-board battery (indicated 13.7ish volts) and the throttle mounted start switch seems to crank a little better than the old motor (the pistons move enough to hear a little grunt or puff from the exhaust), but still doesn't come close to starting the bike. I've yet to try cranking without plugs or to try and jump it straight from another battery since I've got to go to class in the morning, but if both of those tests fail me where do I go from here? Starter clutch assembly?

    My current theory is that the cylinder walls have some kind of crap built up on them from the prolonged storage which is causing unusual resistance to cranking. Is there anything I can do to rule this out? Manually cranking it or some such? Is there some other issue that could be producing the behavior I'm seeing?
     
  14. ridervfr

    ridervfr Member

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    I would take that cover off that is used to turn the motor over for checking valve lash. (think its on the right side, round) Turn it over with a socket and long ratchet and see how it feels. Have the spark plugs out of course. Also I would drain the fuel bowls just for chits and grins and see how much fuel comes out of each one. Be methodical and eliminate all possible mechanical gremlins, you wont be disapointed. My bike is bitching and will be with me for many years to come. Cheers.
     
  15. tris1948

    tris1948 New Member

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    I may have missed something, but does it even try to fire?

    However, assuming that you have fuel and electrics in all the right places and the engine will turn over by hand, why don't you co-opt a couple of strong buddies and try and bump start her??

    It would at least allow all the electrons to concentrate themselves on making sparks which could help and take all the bits associated with the starter( starter clutch, motor, switch, cables, etc) out of the equation.

    Back in the day I can recall being dragged up the road (in a car) by a mechanic buddy with it in gear and ignition on to start a car that had been stood for ages. It did start after a couple of hundred yards.

    NOTE
    I WOULDNT RECOMMEND BEING THAT DRASTIC WITH A BIKE THOUGH !!!!
     
  16. donald branscom

    donald branscom New Member

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    Go back and read post #2 AGAIN by adamjenkins

    DO NOT TRY TO PUSH START THE BIKE. If you did it would need to be in 2nd gear not first . But it is a waste of time and could cause more damage. NEVER tow a bike with a rope. Very dangerous.

    You STILL need to take jumper cables and put the ground on the ground of the frame where there is NO paint. and put the positive wire of the jumper cables on the post of the starter that has the big wire. If the engine spins over then you will know that the problem is the resistance of the start switch or other part. You cannot skip this step.

    Take the plugs out if you have to. IT is NOT "gunk" on the cylinder walls.
    When the plugs are out you could squirt a few drops of oil or in each cylinder. Just a few drops. See the last paragraph of this post.

    When you use the jumper cables it is better if you have a REMOTE START SWITCH between the positive starter post and the red cable of the jumper cables.

    Read this twice.

    "My current theory is that the cylinder walls have some kind of crap built up on them from the prolonged storage which is causing unusual resistance to cranking." WRONG

    How many tears was it stored for?????
    FIVE LONG YEARS.

    If it sits for that many years the piston rings get glued to other metal parts like the piston or cylinder walls because the fuel /oil turns to a sticky varnish that is like glue.

    If you pour s little mystery oil, Seafoam or kerosene into each cylinder over nite it could unglue some of the varnish but most often the top end has to be taken apart because even if you got it started the piston rings will go up and down BUT they will not spin on the piston and can get worn on one side. So the engine will run BUT it will smoke a lot and it will not stop smoking until the piston rings are freed up.

    So just try the oil in the cylinders over night and see if maybe it will spin over the next day. Make sure to give the starter a 5 minute rest between start attempts or you will melt the starter or some wiring and switches.

    None of this was your fault. Remember that.
     
  17. tinkerinWstuff

    tinkerinWstuff Administrator Staff Member

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    [​IMG]

    [​IMG]
     
    Last edited: Aug 13, 2010
  18. rogersj3

    rogersj3 New Member

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    Don, thanks for the reply. I had forgotten to oil up the pistons, so hopefully that helps out. Regarding proper procedure for starting from an external battery applied to the positive post of the starter, yes I properly grounded the negative lead but I don't have a mechanic's start switch so I just touched the positive lead to the post momentarily. I understand the risks involved with not having the current on a switch, and dealt with them appropriately.

    So you think we're looking at the same issue that had frozen my carbs up? I never was able to get those suckers moving; it was as if they'd been soaked in superglue. Assuming a worst case scenario, am I looking at a complete tear down (motor out of the frame, stripped to the pistons and everything)?

    Also, it looks like someone else is having the exact same issue as me over here: http://vfrworld.com/forums/mechanics-garage/32005-motor-stuck-after-storage.html

    Tinkering, too funny mate. Too funny.
     
  19. donald branscom

    donald branscom New Member

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    What is the prognosis?

    I am afraid so. The pistons in the carbs got glued in position by corrosion or gas turning into varnish just
    like the other parts.
    The starter which is geared down has a lot of force and if that will not turn it over with the plugs out then you will have to take the engine
    out and pound the pistons downward in the cylinder with a block of wood until they are out of the cylinders.
    Then you can soak them in degreaser. New piston rings and dingle berry hone job. Be careful when removing the piston wrist pins not to bend the
    rods, and make sure you put the pistons back in facing the right direction and they are from the same cylinder.
    But think about how much it would cost for a new bike that size. Just take your time and do it and you will
    learn a lot and then next summer you can ride your like new bike.
    Its just labor ,gaskets and piston rings.

    And remember. None of this was your fault.
     
  20. rogersj3

    rogersj3 New Member

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    " And remember. None of this was your fault"

    Yep. That reeeealy takes the sting out...:frown:

    What makes all this worse is I bought this from a friend of mine's roommate. I assumed I could trust his opinion on the ease with which this bike could be repaired as he rides as well, but I guess I've learned my lesson there.

    Next season, huh? Man that sucks. Well, taking apart and reassembling an engine has been on my "to-do at some point" list for awhile now. I guess it's not so bad that I ought to have a nice motorcycle when the whole ordeal is over. I'm going to have to work something out with the owners of the garage I'm working in though - the bike was brought in with the understanding of "give me a few weeks" and it's been what, four months now?

    I guess I'll do this the right way; start a new thread on performing a 3rd gen engine overhaul and take lots of nice pretty pictures like I did with the electrical gremlins earlier in this thread. Keep your eyes peeled for that - I'm sure I'll need some advice as I dive into that project. In the meantime, it's coming up on finals week for the Summer quarter down at the University so I'll probably not have much time to work on this in the next couple of weeks. Thanks for all of your assistance.
     
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