Strong vibrations between ~ 5500 and 6500

[dirk]

Hi Guys

The engine has new pistons since 500km.
everything else has remained the same.
but the engine was not mounted 1.5 years.
and the cylinders were removed.

the engine does not feel healthy.
starts immediately.
idle very quiet, incredibly quiet and inconspicuous.
to about 5000 rpm all normal.
from ~ 5500 - 6500 (with about 1/4 throttle) very unusual vibrations in the footrests and handlebars.
engine in this area very rough and somewhat unwilling.
from 7000 rpm the vibrations are less.
performance, however, is only from 9000-11000.
But even in this area of the motor does not run freely and somehow obstructed.

ok with the peak power can also be a bit of conceit.
drove over a year RG500.
the KR missing 2 cylinder ....

however.
the vibrations are not normal.

i have no idea what may be there....

regards
Dirk

[Luders]

Unless your engine bolts are lose I suspect you may have an issue with your crank

[jarno]

Dirk,

check your balance shaft maybee it is off centre, if that is oke Ben is probably right and it wil be your crank. can't think of anything else that vibrate as much in the engine as you say.

unless the engine bolts are loose,but i had that one time and it didn't vibrate that much because the engine is bolt very tight in the frame.

[JanBros]

I once mounted the balancershaft 1 tooth wrong and the engine shaked A LOT , from idling all the way up. so I don't thinck it will be the balancer shaft.

[dirk]

Good evening

Thanks for the answers

bad news

unfortunately it was not the engine mount.
it can not be the balancer shaft.
the bottom end was not open since 13000km.

strange.
when I turned the crankshaft by hand, the bearing felt in order.

regards
Dirk

[JanBros]

is the flywheel tightenned ok ?

[Luders]

Turning something by hand is a lot different to 7,000+ rpm though

[dirk]

good Morning

I will check the flywheel.

Hope dies last [-o<

no luck with the KR
I've only driven a total of 16000km.
that's nothing.

in these times:
a new (used) crankcase
a new crankshaft
once cylinders recoated.
This is the third pair of pistons
nearly all bearings I've exchanged.
the engine mount had to be welded twice.

the bike was two times faster than I -> new fairing

i call that sporty running costs

and we're talking about a road bike and not a racing machine.

under my bed I have two new crankshafts.
now I know why ...

regards
Dirk

[dirk]

Good morning

Flywheel is ok

The only thing that is still noticeable, is when I press the finger from the top of the Kips (left side) I feel an irregular tacking very hard.
So the Kips jumping (as far as the free play permitting) irregular hard upwards.
On the right side everything is ok.
If I pluck at the flywheel, I imagine a very minimal free play to feel.

regards
Dirk

[dirk]

good evening

the engine is disassembled.
all bearings of the crankshaft are perfectly fine.

i hope the crankshaft is out of round or twisted,
so that the work was not in vain. [-o<

cheers
Dirk

[JanBros]

i hope the crankshaft is out of round or twisted,

strange thing to hope for.

crank trouble would be the last thing I wish for.

[dirk]

i hope the crankshaft is out of round or twisted,

strange thing to hope for.

crank trouble would be the last thing I wish for.

Hello Jan

that`s no problem.
i have two new cranks under my bed

if it still vibrates with new crankshaft, then I make a campfire in my garage.
the moped burns surely good ...

engine:
the compression test showed ~ 160 psi cold on both sides.
new Mitaka piston after 500km.





cheers
Dirk

[maccas]

That top ring peg on the right hand piston looks a long way out!

Dan

[dirk]

Hello Dan
good eyes!

i have PJ Motorcycle written.
he says I should return the piston.
he sends the piston then to the manufacturer.

everything will be fine. [-o<

i still have the original piston in the showcase.
maybe I'll take this, so I finally rest ......

cheers
Dirk

[dirk]