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vibration problem around 5k solved!
Posted: Sun Mar 11, 2007 10:33 am
by Charles (Service Informatique Gosford)
Hi all,
I had a vibration problem on my KLR. It would vibrate a lot, but mostly
around 5K RPM and above, wich rendered the bike uncomfortable on the
highway. I researched a lot on the internet about that and the end
conclusion of that research was that for a single cylinder, it was
normal. I lived with it for a while, then rode a friend's KLR. It was
smooth! Well, it did vibrate a little, but not nearly as much as mine.
I bought the Clymer shop manual. For those who don't have it, you
should buy it. The KLR is a pretty simple machine to work on, but the
manual has a lot of details that make troubleshooting a lot easier. I
found a page that mentionned the balancer synchronization. Basically,
there are 2 balancers that are connected to the crankshaft through a
chain (the chain that the Doohickey puts tension on) and act as
counterweight to minimize the vibration caused by a single cylinder 4
stroke engine. Those balancers need to be synchronized with the
crankshaft in order to cancel the vibration. In pure despair, I opened
up the left side cover (make sure you put your piston at TDC before you
do so if you want to check correctly) and took a look. IT WAS OFF! As
far as I know, nobody did any work there that could have caused that, so
it must have been out of factory. I synchronized everything and went
for a test ride..... FIXED!!! I cannot believe it. I did everything
possible on that bike to solve that problem, carburetor, valve
adjustment, valve timing..... heavy bar ends and so and so, and it was
a factory adjustment problem in the engine!
I love the KLR, but I was thinking of selling it for something
smoother.... not anymore!
Happy riding to everyone!
Charles
vibration problem around 5k solved!
Posted: Sun Mar 11, 2007 10:47 am
by Jud Jones
--- In
DSN_KLR650@yahoogroups.com, "Charles (Service Informatique Gosford)"
wrote:
>
> Hi all,
>
> I had a vibration problem on my KLR. It would vibrate a lot, but mostly
> around 5K RPM and above, wich rendered the bike uncomfortable on the
> highway. I researched a lot on the internet about that and the end
> conclusion of that research was that for a single cylinder, it was
> normal. I lived with it for a while, then rode a friend's KLR. It was
> smooth! Well, it did vibrate a little, but not nearly as much as mine.
>
> I bought the Clymer shop manual. For those who don't have it, you
> should buy it. The KLR is a pretty simple machine to work on, but the
> manual has a lot of details that make troubleshooting a lot easier. I
> found a page that mentionned the balancer synchronization. Basically,
> there are 2 balancers that are connected to the crankshaft through a
> chain (the chain that the Doohickey puts tension on) and act as
> counterweight to minimize the vibration caused by a single cylinder 4
> stroke engine. Those balancers need to be synchronized with the
> crankshaft in order to cancel the vibration. In pure despair, I opened
> up the left side cover (make sure you put your piston at TDC before you
> do so if you want to check correctly) and took a look. IT WAS OFF! As
> far as I know, nobody did any work there that could have caused that, so
> it must have been out of factory. I synchronized everything and went
> for a test ride..... FIXED!!! I cannot believe it. I did everything
> possible on that bike to solve that problem, carburetor, valve
> adjustment, valve timing..... heavy bar ends and so and so, and it was
> a factory adjustment problem in the engine!
>
You would not be the first guy that has happened to.
vibration problem around 5k solved!
Posted: Sun Mar 11, 2007 12:55 pm
by Thor Lancelot Simon
On Sun, Mar 11, 2007 at 11:32:22AM -0400, Charles (Service Informatique Gosford) wrote:
>
> crankshaft in order to cancel the vibration. In pure despair, I opened
> up the left side cover (make sure you put your piston at TDC before you
> do so if you want to check correctly) and took a look. IT WAS OFF!
This isn't all that uncommon. One sign that it could be the case with a
particular KLR is if the vibration gets slightly _worse_ when the balancer
adjustment is done every few thousands of miles.
This might actually be worth putting in the FAQ.
vibration problem around 5k solved!
Posted: Sun Mar 11, 2007 6:53 pm
by revmaaatin
--- In
DSN_KLR650@yahoogroups.com, "Charles (Service Informatique
Gosford)" wrote:
>
> Hi all,
>
> I had a vibration problem on my KLR. It would vibrate a lot, but
mostly
> around 5K RPM and above, wich rendered the bike uncomfortable on
the
> highway.
SNIP
> Charles
Charles,
Good work on finding your problem. Remembering what I have gleaned
from list-wisdom, another source-vibration is 1)loose, under
torqued engine mounts (including the upper ones under the tank) and a
2) chain that is way to tight, which also manifests itself
as 'surging'.
Apparently, it was not either of these problems!
revmaaatin.
vibration problem around 5k solved!
Posted: Mon Mar 12, 2007 12:14 am
by Jon Neet
Good job on figuring out the reak cause of the vibrations. Mine must not be out of time because the last time I "adjusted" the balancer tensioner, it really smoothed out the engine.
jon in puyallup
---------------------------------
Looking for earth-friendly autos?
Browse Top Cars by "Green Rating" at Yahoo! Autos' Green Center.
[Non-text portions of this message have been removed]
vibration problem around 5k solved!
Posted: Mon Mar 12, 2007 12:25 am
by Norm Keller
Guess this means we have another task as part of the Doo' replacement. That's an easy time to do the check which (at that point) is a "why not?"
Thanks for the heads up,
Norm
[Non-text portions of this message have been removed]
vibration problem around 5k solved!
Posted: Mon Mar 12, 2007 2:35 am
by Mike
--- In
DSN_KLR650@yahoogroups.com, "Norm Keller" wrote:
>
> Guess this means we have another task as part of the Doo'
replacement. That's an easy time to do the check which (at that point)
is a "why not?"
>
> Thanks for the heads up,
>
> Norm
>
> [Non-text portions of this message have been removed]
>
There might be a couple of things to consider as one does this. The
sprockets have 18 teeth, so for every revolution of the cranshaft the
chain will advance 18 links, right? The chain has 70 links, so the
marked links on the chain will not line up every revolution of the
engine (to TDC), or every revolution of the chain. IIRC, it take 9
revolutions of the chain for all to correctly line up again. (it's
late and I have a headache) You can do the math as well as I, I'm
sure. Least common multiple, right?
Also - remember the bolts holding the chain guides on are made of
compressed oatmeal, and loctited with red loctite. Heat is your friend
if you need to remove the bolts.
all the best,
Mike
vibration problem around 5k solved!
Posted: Mon Mar 12, 2007 7:38 am
by Charles (Service Informatique Gosford)
Hi Mike,
You are right about that, if you look at the marks on the chain and the
lineup with the gear, it might take a couple of revolution to line up
properly. A good indicator are the marks on the sprocket. I compared
the small alignment dots on my sprockets and where they were pointing
with the picture in the shop manual and they were way off. But you are
right, the chain alone doesn't tell everything .
As for the chain guides, I had no problem at all removing them and no
locktite was there. May be somebody did it before I did....
>
> There might be a couple of things to consider as one does this. The
> sprockets have 18 teeth, so for every revolution of the cranshaft the
> chain will advance 18 links, right? The chain has 70 links, so the
> marked links on the chain will not line up every revolution of the
> engine (to TDC), or every revolution of the chain. IIRC, it take 9
> revolutions of the chain for all to correctly line up again. (it's
> late and I have a headache) You can do the math as well as I, I'm
> sure. Least common multiple, right?
>
>
vibration problem around 5k solved!
Posted: Mon Mar 12, 2007 10:57 pm
by Blake Sobiloff
On Mar 11, 2007, at 8:32 AM, Charles (Service Informatique Gosford)
wrote:
> I had a vibration problem on my KLR. It would vibrate a lot, but
> mostly
> around 5K RPM and above, wich rendered the bike uncomfortable on the
> highway.
Very interesting to hear, Charles! I have a similar complaint, with
a bad vibration in the right footpeg at 5K RPM. My answer to date
has been to use the passenger footpegs for long highway stints, or to
wear my motocross boots.
I've been wanting to give the torsion spring doohickey a try, so I
may do the same balancer synchronization check while I'm in there and
see if my bike's similarly mis-adjusted.
Thanks for the tip!
--
Blake Sobiloff
http://sobiloff.typepad.com/blakeblog/>
http://sobiloff.typepad.com/klr_adventure/>
San Jose, CA (USA)
[Non-text portions of this message have been removed]
vibration problem around 5k solved!
Posted: Tue Mar 13, 2007 12:28 am
by E.L. Green
--- In
DSN_KLR650@yahoogroups.com, Blake Sobiloff wrote:
> On Mar 11, 2007, at 8:32 AM, Charles (Service Informatique Gosford)
> wrote:
> > I had a vibration problem on my KLR. It would vibrate a lot, but
> > mostly
> > around 5K RPM and above, wich rendered the bike uncomfortable on the
> > highway..
>
> I've been wanting to give the torsion spring doohickey a try, so I
> may do the same balancer synchronization check while I'm in there and
> see if my bike's similarly mis-adjusted.
Hey Blake! I did the balancer synchronization check/fix when I did my
doohickey, but it didn't help much, if at all. My bike still vibrates
at high rpm's. I just view it as a foot massage and ignore it
.
Looking at the mechanism, I just have to shake my head. This is no way
to design a balancer mechanism. The problem is that it really isn't
adjustable. The balancers on a lot of other bikes are adjustable so
that you can move the weights slightly fore or aft to find the "sweet
spot" that exactly counteracts the thrashing of the piston at your
typical cruising rpm. With the KLR mechanism, you can only jump entire
teeth, which is way too granular to do a real adjustment. As the chain
wears and the guides wear, the whole mechanism slowly drifts, and
there's no real way to "fix" it short of replacing major parts or
doing some major machine shop work. For those of us with high-mileage
bikes, putting up with some vibration seems to be pretty much a given,
because the mechanism simply lacks the adjustability to compensate for
normal wear and tear.
_E