Good Vibrations

[rhpaw]

So 've always heard how smooth these visions are with their balance shaft that takes out all the vibes.. I can say yes, at idle to cruise RPM these things are really smooth.. Not SV650 smooth, but pretty damn smooth.

But, dammit if my jaunts into high RPM lands to clean the carbs havn't introduced an annoying high frequency vibe starting at about 7500 and up to redline... As I've been banging+hanging around in that range a bunch lately to clean the high speed jets I find my nuts are falling asleep!!!

Normal?

I'm having a hard time deducing if this is expected as I come from the king and queen of vibration.. I usually have shit falling off the Buells at intersections with long lights. But after 2500rpm, the B's smooth right out.
?
I do notice the handlebar vibes too, they seem to start at a slightly lower RPM, around 6k. Nothing bad but I do think it would get fatiguing after a while.

So, I was going to go off and get some nice gel or contoured grips and possibly bar ends weights too. Since this bike has a single cable instead of those fancy-pants dual setups, would a modern set of grips work ok or should I expect to modify them a bit?

[Rick G]

My experience with the Sv650 , was that at lower rpm, it pulsed ,it smoothed out until you wind it up and then it tingled in the bars and the pegs.
Be sure your motor mounts are tight and consider replacing the 4 bolts the attach the removable lower frame rail on the right side, with some 12.5 grade hardware.

[rhpaw]

I've only rode an SV a handfull of times, but I've always thought it was much to civilized to be a twin. Damn near "Germanic".
But now that you mention it, I could see the pulsey reference.

Grade 12 hardware huh? ok, time to go see my favorite redhead down at the Fastenal

[QBS]

Vs have a bit of a hand grip high frequency vibe above 6k rpm.  Not a deal killer though.  I've numerous 7.5k rpm days without much complaint.  But, foam grips are a huge improvement.  I would never own a V without them.  What does really vibe on a V are the passenger foot pegs.  They are killers.  Reach back and down when cruising at 6k rpm and you'll see what I mean.  A potenial fix might be to fill in some of their rear most casting spaces with lead (it would take a lot).

Well tuned/synched carbs are the place to start for vibe abatement.

[rhpaw]

My carbs are still an issue, I know that. They're getting 'pretty good' but I smoking bullet last night that my cable is kinked, so it's not always closing the butterfly correctly.
I have a new cable on order now and hopefully that should solve my unpredictable idle / sync issues.

( I would be adjust and adjust and the bike would idle high/ low/ middle.. but if I forced the plate closed, then I could get an accurate reading -until I goosed it again.)
Still, I was under the impression that no matter what, what the carbs are doing at idle to -3k has just about NOTHING to do with what the carbs are doing at 8k.

No matter how much I sync these guys, if I get the box synced at idle, when I raise throttle the machine will go out of sync. The difference gets wider as RPM's go up. (I can't recall which end is having more vaccumn).. Anyway, knowing that, wouldn't you want to sync your carbs at mid range like 4500, and split the difference with a less than ballanced idle, but much more in sync where we're actually riding?
besides, you MIGHT be able to trim out the imballance down low by then adjusting your mixture screws. - don't those become moot after the 4500?

[don_vanecek]

Humm, not sure what to tell you, at 7500 your talking about 84 mph plus, not a usual cruising speed. My last cruise down I-29 last September at 70-75 mph, or about 6500-6800 rpm my V felt like I had an electric motor moving it-it was really in a sweet spot. Many of us will swear that the more you run these bikes the better they run!

I do wonder as to how well carb syn effects smoothness of operation but I'm not so sure at the rpms your talking about that the motor is not out of it's expected cruising range and will have some tingle. 

[rhpaw]

We found this bike with unknown jistory and it hadn't run in ages.. I'm just trying to get it back to a fine running status.
If numb nuts is a situation that exists up above 8500, then it's just something to remember.
8)

I wasn't going 85.. I'm trying to run it in high rpm with lots of Berryman's in the tank to clean out the high speed feeds. I was doing my racing around in second or third. Sane speeds.


.....Oh, and I just did a long search on the carb syc/ idle/ high deal and I now understand that sync is done AT IDLE. No worries on that tidbit.

[Tiger]

... Many of us will swear that the more you run these bikes the better they run!

8) 100% agree with this Don... 8)

                  8).......TIGER....... 8)

[rhpaw]

... Many of us will swear that the more you run these bikes the better they run!

8) 100% agree with this Don... 8)

                  8).......TIGER....... 8)

I have a lot of stuff like that too. (already)

[Night Vision]

Ahhh, syncing the carbs can drive ya nuts!
Syncing the carbs correctly can have a big effect on overall smoothness of a Vision...

yes, the carbs are supposed to be sync'd at idle, and yes they go out of sync when you rev it above idle...

the interesting thing though, is: mine don't go out of sync when I rev past idle...
let me clarify that... RedSkunk doesn't go out of sync... SmokeBomb and probably all the other visions do...

WHY? probably because I have an '82, the predator exhaust, my air pilot / main / and the fuel pilot jets are the same sizes front and back.

I even went as far as syncing the carbs at 3500 rpm on SmokeBomb (thinking was that most of my riding was between 3500 and 7000 prm....) that really didn't have as much as an effect as I would have expected, just as smooth as syncing at idle.

I agree that the more you run these bikes, the better they run.  That can even happen within a single day.
With SmokeBomb, I can start off on a 200 mile ride and she's running good.... 100 miles into the ride... she's running great!...
Let the bike sit for a week, or commute to work all week, she'd back to running good again...

my brother (who also has a Vision) once said: "She's running like a 750!!!"

I said: "don't worry, that'll change!"

[akvision]

Hey Son,

I most likely will not run much over legal speed limits.  Will most likely keep it under 8k.  I know, Boring!
lastly, you were the last one and my nuts do not ever get numb, no matter what.  We fixed that.

Also, I appreciate your diligence and excellent effort in getting this thing right for your pop.

akvison

[rhpaw]

I just need to know that the vibes are all in the right spot Pop... Nothing worse than driving through Utah to find that the weird vibe that happened at 8500 now seems to be happening more at 7000 and then 6000..
and
"oh shit, I'm gonna get stuck in utah!"

It's not really about the nuts.
My wife keeps mine in the drawer by the bed anyway!

[vadasz1]

Hey rhpaw, so is the wifie also known as the 'lhpaw'?

[rhpaw]

lol. I have a few names for her depending on the situation...

but we won't go there. :-\

Actually just had a good one..
"Left Home, Put Away Whining!"

[Rick G]

I always sync carbs at 2500 rpm , . Its the way i was taught. I find they run smother with better throttle response  that way.

[Glyn]

I'm riding the Vision and my other bike a 1981 Honda CX 500 on alternate days to work. The CX was smooth for a twin in it's day but the XZ is the smoothest bike I've ever ridden. In a way a bit too smooth for a twin.  Was getting mid frequency vibes on the Honda and ended up putting 10 oz of fishing weight lead in each bar end. I squashed slightly too large diam weights in a vice till they just fitted down the tube. I came to 10 weights since that was how much each bar side took till it was full. It defn made a great improvement.

[supervision]

  The throttle shaft, on my front carb, had become a loose fit between, the shaft, and the linkage.  It is supposed to stay put forever, but had become loose, over time.  You could see the play, just off idel, and made it not run, too well.  My yikes, is home made, and the hoses to connect the two chambers, are not equal. I decided to leave the yikes in play, while syncing, this time, I set it up at about 1,550, but now, it could idel at very low rpm. I am happy, with the results. It starts cold, and fast idel @ 1/2 choke, is nice and smooth!  I took the shaft, from a donor set, I had, I realised, that  my carbs only have 1 accl nozzle!  The donor set has 2 !  Maybe someday, I'll fix mine with the double set-up.  Maybe after the chores are done, I'll ride

[funkamongus]

ak,,, I agree.. Rhpaw is doing a fine job gettin the bike ready for ya! You did good, Ak.. You have a good son..

[inanecathode]

Few quick things:

Seafoam/berrymans and hard running doesnt seem to really do a whole lot as far as cleaning goes. I've yet to hear of a problem that was solved by tuneup in a can, not to say it doesnt work, but the deposits you'd have in your jet passages are ancient and dried out.

Sync: The sync is just to get the butterflys to open at the exact same time. The only way you can tell this is either by ear, looking at it, or vacuum ONLY at idle. They WILL go 'out of sync' the more they're opened or the more rpm they're turning. Vacuum signals for sync purposes are only good at idle rpm with the plates closed. If you remember, the jets are even different sizes front to back, let alone where the carbs get air from the box, they'll never be high rpm vacuum synced. The only thing you have any control over as far as sync is when they open, and where they are at in the throttle range. If you set it at idle, and the linkage isnt bent it's fine.

As far as stumblyness etc, make ABSOLUTELY SURE theres no vacuum leaks, and make ABSOLUTELY SURE the carbs are cleaned. Dip them for a real long time, and mechanically go through as many of the jet passages as you can, compressed air/pipe cleaner with the rest. I know its a pain in the ass but you have to be sure.

Something else to think about is ignition issues. Make sure the primary connections are clean and well insulated, and the secondary wires and connections are totally clean, touching, and well insulated. Also, make totally sure the coils arent cracked at all and the plugs are new, gapped correctly, and totally clean. It might run good 90 percent of the time, but when the plugs are under high load its real tempting for the voltage to eek out elsewhere instead of in the cylinders.

Hope that helps :D

[Rick G]

I have a couple of points of disagreement with Inane. I was trained by those ( technicians of long and varied experience.) who felt the sync off idle was more important , say at 2500 rpm and I always check sync there. You don't ride the bike at idle , it accelerates better and smoother when synced at a higher rpm.
NEVER dip any carb, that has a butterfly shaft, for "a real long time " if you leave them in the dip longer than 30 min. it is possible to damage the butterfly seals ( which Yamaha never supplied, although Polaris does, for Mikuni equipped ,older ATVs.  I use air to clean every passageway, and then use spray cleaner to verify that they are clean.
If your bringing a dormant Vision back to life , pick up some spark plug wire , IE: wire that has real wire in side , not carbon impregnated nylon string, as used in automobiles. Most lawn mower/ snow blower shops will have this kind of wire.