Just finished my first valve adjustment, a lil nervous

Discussion in '1st & 2nd Generation 1983-1989' started by rickjames, May 16, 2012.

  1. rickjames

    rickjames New Member

    Joined:
    Jan 25, 2010
    Messages:
    30
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    PA
    Map
    As the title states i just finished my first ever valve adjustment on my new to me 84 vf500f:smile:. The good news is i saw no signs of damage as i was poking around in there; that is particularly exciting since when i rode it home from the sellers house i noticed a bit more than a small tick coming from the back cylinder head. I fired it up briefly after buttoning everything back up, and definitely didn't hear that same tick again. I still am a bit worried about it though since these have a history of top end failure and i have no history of doing valve adjustments. I am curious if anyone has had the job done at a dealership and can give me an idea of how hard they may bend me over a barrel for it. I know its silly to think about having the same job done twice, but really like this scooter and want to keep it around as long as possible.

    P.S. Sorry for the long post its 4 AM and I may be a tad less than sane right now.:crazy:
     
  2. Dukiedook

    Dukiedook New Member

    Joined:
    Oct 16, 2009
    Messages:
    979
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Kansas City, USA
    Map
    Did you check the readings after you completely adjusted them? And you did the two feeler method?
     
  3. rickjames

    rickjames New Member

    Joined:
    Jan 25, 2010
    Messages:
    30
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    PA
    Map
    I fired it up this morning and it definitely tapped quite a bit so i shut it back down. I think i am going to take another stab at this tomorrow after work. I believe the valve adjusters moved when i tightened the lock nuts thus throwing things out of whack. Can someone recommend a write up on the procedure to supplement the crappy Chlymer manual? I did use the 2 gauge method and double checked, but it was 4AM so I may have been a touch haggard.
     
  4. Pops

    Pops New Member

    Joined:
    Dec 20, 2011
    Messages:
    120
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Stephenson, VA
    Here's a great link with step by step and illustration.

    ValveTrain/ValveClearanceAdjustment - SabMagFAQ

    Not sure about clearances for the 500, but over the years the V45s clearance recommendation has gone from .005 to .006 in the interest of saving the cams/followers.
     
  5. squirrelman

    squirrelman Member

    Country:
    United States
    Joined:
    Jul 27, 2006
    Messages:
    9,838
    Likes Received:
    743
    Trophy Points:
    128
    Location:
    Buffalo, NY
    Map
    Yes, the clearance does usually shift a bit toward the narrow side when you tighten the locknut, so you need to learn to compensate or use the fancy factory tool.
     
  6. rickjames

    rickjames New Member

    Joined:
    Jan 25, 2010
    Messages:
    30
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    PA
    Map
    Alright so i made a second attempt to adjust the valves this evening. I did the two feeler method and a torque wrench to tighten the adjusters. When i fired it up the engine ran smoothly for about fifteen seconds before one of the front cylinders began to tap rather loudly so i shut it down immediately. Where could i have gone wrong and does anyone think i did any serious damage to the engine in that time?. If I understand the operation correctly even if I am way off on my adjustment a few seconds shouldn't hurt the engine.
     
    Last edited: May 18, 2012
  7. squirrelman

    squirrelman Member

    Country:
    United States
    Joined:
    Jul 27, 2006
    Messages:
    9,838
    Likes Received:
    743
    Trophy Points:
    128
    Location:
    Buffalo, NY
    Map
    Before anyone tries a valve adjustment for the first time, i'd suggest that they go all around measuring and recording all the clearances on paper. If nothing is off spec more 1 or 2 thousandths, don't touch anything !!

    Look for patterns or trends of loose or tight on both intake and exhaust. Get a baseline reading when you get into the motor the first time, record #s and check again miles later to see if things have stayed the same or not.

    Don't bother touching valves that are loose less than .002" from spec.

    Exhaust valves are more critical for accuracy, and too little clearance is what you need to avoid.

    It's helpful to place a dot of paint or nailpolish on the head of each adjustmernt screw so you have a clear reference for that point before and after adjustment, which will NEVER be more than about 1/8 turn + or -.

    ALWAYS turn the engine over BY HAND a few revolutions with a socket on the end of the crankshaft after doing cam or valve work to check for tightness or stopping points, which would indicate a valve kissing a piston......in a not-so-romantic way.

    |You asked about possible damage, and now you'd best do a compression test to check.
     
  8. rickjames

    rickjames New Member

    Joined:
    Jan 25, 2010
    Messages:
    30
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    PA
    Map
    I did roatate the motor by hand after adjusting the valves and felt no resistance more than just pushing against the valve springs. I appreciate the advice Squrilleman, but a friend has recommended a mechanic he knows who is supposedly very good with old fragile bikes. I am going to call him monday and admit that this job has defeated me. I did however do a compression test and found everything was kosher. You mentioned that a valve could kiss the piston if they were adjusted improperly, I am no master mechanic, but i would think that either the valves would have to be WAY out of adjustment like several hundreths of an inch??? I dont know anymore this job has defeated me utterly and completely.
     
  9. squirrelman

    squirrelman Member

    Country:
    United States
    Joined:
    Jul 27, 2006
    Messages:
    9,838
    Likes Received:
    743
    Trophy Points:
    128
    Location:
    Buffalo, NY
    Map
    It's great to see what a learning experience you're getting with this.....and that that sometimes involves pain.

    There is a small but non-neglible chance that due to a bad camchain tensioner or other mishandling, you could have possibly jumped a sprocket tooth, messing up the valve timing. Not likely but possible, and that would cause lots of tapping.
     
  10. rickjames

    rickjames New Member

    Joined:
    Jan 25, 2010
    Messages:
    30
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    PA
    Map
    I really am learning a lot trying this, but I am going to have razor blades in my stomach until i get it to the shop. Hopefully its just me being a bit dense and having the adjusters a bit off.
     
  11. rickjames

    rickjames New Member

    Joined:
    Jan 25, 2010
    Messages:
    30
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    PA
    Map
    Oh squirrelman what type of mishandling would cause the cam chain to jump a tooth? I cant thing of anything in the process that would cause the chain to jump a sprocket. Possibly rotating the engine by hand?
     
  12. squirrelman

    squirrelman Member

    Country:
    United States
    Joined:
    Jul 27, 2006
    Messages:
    9,838
    Likes Received:
    743
    Trophy Points:
    128
    Location:
    Buffalo, NY
    Map
    What ?? Not all mystries have a solution. I'm not sayin, just guessin' possibilities.
     
  13. rickjames

    rickjames New Member

    Joined:
    Jan 25, 2010
    Messages:
    30
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    PA
    Map
    I am simply speculating as well, sorry just looking at all the possibilities. I've yet to own a vehicle that i haven't taken mostly apart, and this is the first one i have had difficulties with. It is very different from my car or my old harley, which had an engine that would not have been foreign to a mechanic from the turn of the century.
     
  14. rickjames

    rickjames New Member

    Joined:
    Jan 25, 2010
    Messages:
    30
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    PA
    Map
    So i bit the bullet today and it off at the dealership. I was quoted only 2 hours of shop time( unless i buggered something up) for a grand total of 200 bones with my state inspection.
     
  15. Dukiedook

    Dukiedook New Member

    Joined:
    Oct 16, 2009
    Messages:
    979
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Kansas City, USA
    Map
    Yeouch, that is painful. 200 bones for a valve adjustment, ouch.
     
  16. Rubo

    Rubo New Member

    Joined:
    May 6, 2009
    Messages:
    461
    Likes Received:
    7
    Trophy Points:
    0
    $200 is rather extremely reasonable.
    Try 800-1500 average for VFR800
     
  17. Mohawk

    Mohawk New Member

    Joined:
    Jun 8, 2010
    Messages:
    559
    Likes Received:
    5
    Trophy Points:
    0
    Location:
    Bristol
    Sounds like you had a locknut not done up correctly & it came loose, get in their & check it ASAP, don't run the engine again until you have confirmed 16 tappets have 16 locknuts on them & that they are tight !

    The VF500 series did NOT have any issues with their valve train or cams, that is all a hang over from the VF750F issues. The VF400F & the VF500F/F2 all had good cams & no issues due to manufacture. All bikes with Y shaped cam followers suffer from the same problem which is a tiny amount of wear on the follower bearing can lead to poorly adjusted valve clearances which then lead to other issues ! The answer is NOT the 2 feeler gauge method IMO, which is rather difficult to do in the confined space available.

    The simple answer is as follows & based on the factory tool solution without the tool ! Look at the centre of the Y shaped follower between the lock nuts, get a short flat blade screw driver with a wide blade, as in a minimum 5-6mm, now adjust the cam on whatever cylinder to TDC position, then place the flat of the screw driver under the centre of the Y & rest the shaft on the edge of the cylinder head, apply a little donwards pressure to the other end of the screw driver (you can hang a small weight on it) this will both centre the follower on its bearing & ensure that it is in proper contact with the cam & that there is NO clearance in the follower bearing. Now adjust each tappet/locknut to the correct clearance. Do all valve clearances, always turn the engine FORWARDS, which is clockwise when viewed from the right side of the bike. NEVER turn it back if you over shoot the timing mark. To make this easier, you can remove the plugs, then there in no compression messing with your turning !

    With some practice you will learn how much the tappet tightens up when torqing the nuts up, so you can either use a slightly thicker feeler gauge, or set it a little loose before tightening. Try to get both tappets on each Y as close to each other as possible or the Y is forced to rock on its bearing when a tight one hits valve first followed by a loose one ! This increases the wear & the clearances go out of spec quicker, so its better to do it right even if it takes a few goes ! If you really want to do it right & get the best settings that last the longest, get a complete spare set of tappet screws & change them all when you set the clearances. Note the shape of the top of new tappets compared to used ones. Used ones will have a chamfer, caused by wear contact with the valve stem. When you adjust a used tappet, you reduce the bearing surface due to the chamfer having changed angle, this then leads to faster wear of the tappet end & the clearances opening up sooner.

    You can rework the tips of the old tappets before the next valve adjustment so that you get the benefit every time. But be extremely careful NOT to drop the tappet or nut into the engine when changing them. I had a VF500F2 for years & ranted the guts out of it all the time. Fully synthetic oil & filter every 2500miles & valve check/adjustments every 5000miles. I had it dynoed at 56K/miles & it showed 59rwhp, bog standard engine with K&N filter, the torque & power spread was better with the snorkel in the airbox lid than with it removed, so apart from making more noise, it messed up the fueling, so leave it in.

    Good luck with the valve adjustment.
     
    mike alexander likes this.
  18. squirrelman

    squirrelman Member

    Country:
    United States
    Joined:
    Jul 27, 2006
    Messages:
    9,838
    Likes Received:
    743
    Trophy Points:
    128
    Location:
    Buffalo, NY
    Map
    All excellent advice, Guvna'
    View attachment 18297

    I did it a long while back, but someone needs to step in once in a while and repeat that the working surfaces of the adjustment screws take an 'orrible beating, develop flat spots that cannot be adjusted properly or hold the adjustment due to reduced bearing area and more concentrated pressure between valve head and adjustment screw. One might be tempted to file or sand the mangled tip round again, but it's probably heat-treaded and removing the surface might soften it up unduly.


    Any idea if virgin adjustment screws are available from Honda ??

    If not, it doesn't seem that a proppa clearance setting which would last is possible with damaged, irregular screw tips. More evidence that old bikes without available replacements for high-wear items may be more trouble than they're worth.
     
    Last edited: May 22, 2012
  19. Mohawk

    Mohawk New Member

    Joined:
    Jun 8, 2010
    Messages:
    559
    Likes Received:
    5
    Trophy Points:
    0
    Location:
    Bristol
    The tappet screws are hardened steel, but not just surface treated, so you can reshape used ones, so long as you do it cold, either with a file, hard work, or a liquid cooled lathe/grinder. If it get to hot it will lose its temper & I don't mean get angry :)
     
  20. rickjames

    rickjames New Member

    Joined:
    Jan 25, 2010
    Messages:
    30
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    PA
    Map
    Well its with the good folks at wast hills Honda now they will have it back to me Thursday allegedly. I am waiting with bated breath to see if i severly buggered anything up but much thanks for the advice. If I decide to try again next time the service comes up due i will save this thread, but for only the two hours of shop time they are going to charge me it might be worth it to let a pro mechanic do it for me.
     
Related Topics

Share This Page