What causes the bike to jump forward 2ft when starting up?

On Sep 24, 5:23?pm, "smn" wrote:
> Ever since I filled the oil, and I put a whole liter in a 850ml oil
> compartment, the bike jumps strongly forward. What causes that. A loose
> clutch cable causing it to go in gear? And what does the oil refill have
> to do with that? Oh yeah, it crawls at 3-4 mph with the clutch in and the
> throttle closed whilst in first gear too. Spooky

A quart of oil is 0.946ml,

A slight overfilling of the crankcase shouldn't cause the problem you
describe, but if you added, say, straight 50-weight oil instead of the
recommended 10w40 oil, you might run into a clutch that wouldn't
release.

I tried 90 weight gear lube in a Yamaha dirt bike once, and I could
hardly kickstart the bike while it was in gear, the clutch wouldn't
release enough.

Check the clutch cable for excess slack. You should have about 1.0 to
1.5mm free play at the adjuster on the clutch lever bracket.

http://houseofmotorcycles.bikebandit.com/partsbandit/ShowSchematic.asp...eptId=7

Loosen #21, turn #20 counterclockwise to take excess slack out of
cable,
retighten #21 hand tight.
 >> Stay informed about: What causes the bike to jump forward 2ft when starting up? 

wrote in message

> On Sep 24, 8:23 pm, "smn" wrote:
>> Ever since I filled the oil, and I put a whole liter in a 850ml oil
>> compartment, the bike jumps strongly forward. What causes that. A loose
>> clutch cable causing it to go in gear? And what does the oil refill
>> have
>> to do with that? Oh yeah, it crawls at 3-4 mph with the clutch in and
>> the
>> throttle closed whilst in first gear too. Spooky
>
> Normally just the lower bit of the clutch is in oil. By overfilling
> the oil more of the clutch is in it causing more drag between the
> drive plates and the driven plates.

Mine always did this worse cold than warm. Once the thick oil thins a bit,
its usually a non issue.


>
 >> Stay informed about: What causes the bike to jump forward 2ft when starting up? 

smn wrote:
> to do with that? Oh yeah, it crawls at 3-4 mph with the clutch in and the
> throttle closed whilst in first gear too. Spooky

I think this is a big hint right here - something is up with the clutch.

- Kurt
 >> Stay informed about: What causes the bike to jump forward 2ft when starting up? 

"smn" wrote in message

> Ever since I filled the oil, and I put a whole liter in a 850ml oil
> compartment, the bike jumps strongly forward. What causes that. A loose
> clutch cable causing it to go in gear? And what does the oil refill have
> to do with that? Oh yeah, it crawls at 3-4 mph with the clutch in and
> the throttle closed whilst in first gear too. Spooky

too full and I used 20/50 okay thanks The clutch cable I will look at too
but it is probably the oil because it happened coincidentally to that.
 >> Stay informed about: What causes the bike to jump forward 2ft when starting up? 

bsr3997.RemoveThis@my-deja.com wrote:
> On Sep 24, 8:23 pm, "smn" wrote:
>> Ever since I filled the oil, and I put a whole liter in a 850ml oil
>> compartment, the bike jumps strongly forward. What causes that. A loose
>> clutch cable causing it to go in gear? And what does the oil refill have
>> to do with that? Oh yeah, it crawls at 3-4 mph with the clutch in and the
>> throttle closed whilst in first gear too. Spooky
>
> Normally just the lower bit of the clutch is in oil. By overfilling
> the oil more of the clutch is in it causing more drag between the
> drive plates and the driven plates.
>

+1

Using too thick of an oil can cause it as well.

But you should probably drain out the extra oil, as there other problems
that overfilling can cause.

--
"Outback" Jon - KC2BNE
outback_jon.RemoveThis@ver.no.sp.am.izon.net
AMD Opteron 146 (@2. and 6.1 GHz of other AMD power...
http://folding.stanford.edu - got folding? Team 48435

2006 ZG1000A Concours "Blueline" COG# 7385 CDA# 0157
1980 CB750F SuperSport "CoolerKing"
 >> Stay informed about: What causes the bike to jump forward 2ft when starting up? 

On Sep 24, 9:37?pm, "smn" wrote:

> too full and I used 20/50 okay thanks The clutch cable I will look at too
> but it is probably the oil because it happened coincidentally to that.

You can easily free up the clutch disks before you start the engine.
Old time motorcycle racers used to do this trick all the time during
the winter.

Just put the transmission in gear, pull in the clutch lever and push
the bike backwards three feet, then put the transmission in neutral
and start the engine.

What oil does your Suzuki owners manual recommend? Has it been rather
cold where you live? Cold weather causes engine oil to stick the
clutch disks together.

10w30 motor oil with special friction modifiers is often recommended
for engines consistently operated at lower temperatures, while the
thicker 20w50 oil is recommended for engines consistently operated at
higher temperatures.

I know some riders are going to be horrified by the concept of oil
with "special friction modifiers" being used in a motorcycle engine
with a clutch that runs in engine oil, but, are the motorcycle
engineers really so stupid that they don't know what kind of oil is OK
for your Suzuki?

I can make my GSXR750's clutch slip at high RPM, but it has 100
horsepower. Your bike probably has 20 horsepower.
 >> Stay informed about: What causes the bike to jump forward 2ft when starting up? 

On Sep 25, 8:47?am, "smn" wrote:
>I have the little window for oil level but do not know if the bike has to be
> upright or not.

Yes, the motorcycle has to be vertical with both tires on level on
level ground, or you won't get the correct level in the sight glass.

> Does slip the clutch mean changing gears without using the clutch
> because I can do that.

No, slipping the clutch is when you don't let the clutch lever all the
way out, but you keep revving the engine up to keep it in the power
band where it continues to pull.

Old-time motorcycle racers were stuck with 4-speed transmissions, and
first gear was too tall (small numerical ratio) for the motorcycle to
go around a corner unless they slipped the clutch to keep the engine
in the power band.

You do not have the tall first gear problem with your Suzuki, the
engineers designed the transmission so you can climb steep hills and
go around slow corners without slipping the clutch.

On the street the only time you would be slipping the clutch is when
you
start moving in first gear, and once the motorcycle starts moving, you
don't need to slip the clutch anymore.

Some drag racers call slipping the clutch "feathering the clutch".

> the 20/50 could damage or stop the ignition
> though because of its pressure rating.

I cannot imagine how that would be true. You have an electronic
ignition system with a pulser coil trigger, and no part of the
ignition system is exposed to oil pressure.

>If bleeding does not start the engine I may need to change back to 10/40.

If you live in a cold climate and don't have to ride in hot desert
conditions,
10w40 will probably be fine. It gets up to 100 degrees every day
around here, from Memorial Day until the middle of September, so I
need 20w50 oil.

I would think the 20/50 might
> be good for storing it over the winter. Once it has warmed up and gone
> through the gears or are people saying that will drag the gears and actually
> gum it up good?

New 20w50 oil is only too thick for your engine when it's cold.

But oil keeps "refining" itself more and more as it is heated and
reheated by the engine. Volatile fractions continue to boil out of the
oil and it winds up as a thick sticky mess that won't flow through the
oil passages to get to the places that need lubrication

Old petroleum-based oil turns brown as it becomes more and more waxy
and it turns black with carbon specks accumulating in it, but you can
avoid old oil thickening up by changing it often.

> If I start it in neutral I do not think there is any pull forward but
> then again the battery was too low by that point anyway.

Like I said before, if you're having problems with the clutch dragging
when the engine is could, put the transmission in gear while when
engine isn't running, pull the clutch lever in, and back up three feet
to break the clutch disks apart.
 >> Stay informed about: What causes the bike to jump forward 2ft when starting up? 

On Sep 25, 11:04?am, "Dave" wrote:

> No slip the clutch means the clutch is slipping... it is failing to transfer
> all available power from the engine to the transmission, i.e. the friction
> of the clutch plates is being overcome by the torque of the engine.

Have you ever been to a 125cc GP race or a shifter kart race?

The racers intentionally slip the clutch in slow corners to keep the
engine in the power band.

Multiplate clutches are designed to be slipped and operated at high
rpm and may be oil-cooled or air-cooled.

Shifter cart drivers never use the clutch for shifting gears, only for
slipping on the starts and in slow turns.
 >> Stay informed about: What causes the bike to jump forward 2ft when starting up? 

"~" wrote in message

> On Sep 24, 9:37?pm, "smn" wrote:
>
>> too full and I used 20/50 okay thanks The clutch cable I will look at
>> too
>> but it is probably the oil because it happened coincidentally to that.
>
> You can easily free up the clutch disks before you start the engine.
> Old time motorcycle racers used to do this trick all the time during
> the winter.
>
> Just put the transmission in gear, pull in the clutch lever and push
> the bike backwards three feet, then put the transmission in neutral
> and start the engine.
>
> What oil does your Suzuki owners manual recommend? Has it been rather
> cold where you live? Cold weather causes engine oil to stick the
> clutch disks together.
>
> 10w30 motor oil with special friction modifiers is often recommended
> for engines consistently operated at lower temperatures, while the
> thicker 20w50 oil is recommended for engines consistently operated at
> higher temperatures.
>
> I know some riders are going to be horrified by the concept of oil
> with "special friction modifiers" being used in a motorcycle engine
> with a clutch that runs in engine oil, but, are the motorcycle
> engineers really so stupid that they don't know what kind of oil is OK
> for your Suzuki?
>
> I can make my GSXR750's clutch slip at high RPM, but it has 100
> horsepower. Your bike probably has 20 horsepower.

I have to bleed some oil first cause that definitely causes problems. I
have the little window for oil level but do not know if the bike has to be
upright or not.
Does slip the clutch mean changing gears without using the clutch
because I can do that.
Thanks for all the help folks. You saved my engine most likely.
The 20/50 is for high revving engines but then so is the 10/40. The
former has the same range of friction but is on the heavy side. It is
synthetic, at least I got that right. Not sure if it has detergent in yet
but that is a must too I read. the 20/50 could damage or stop the ignition
though because of its pressure rating. If bleeding does not start the
engine I may need to change back to 10/40. I would think the 20/50 might
be good for storing it over the winter. Once it has warmed up and gone
through the gears or are people saying that will drag the gears and actually
gum it up good?
If I start it in neutral I do not think there is any pull forward but
then again the battery was too low by that point anyway.

Suzuki DR200
 >> Stay informed about: What causes the bike to jump forward 2ft when starting up? 

On 9/25/07 8:47 AM, "smn" wrote:

> I have to bleed some oil first cause that definitely causes problems. I
> have the little window for oil level but do not know if the bike has to be
> upright or not.
>
You DO have an owner's manual, don't you? If not, get one. If so, read it!

Most bikes with oil level windows are meant to have their oil level checked
when the bike is sitting upright on a level surface.


> Does slip the clutch mean changing gears without using the clutch
> because I can do that.
> Thanks for all the help folks. You saved my engine most likely.
> The 20/50 is for high revving engines but then so is the 10/40. The
> former has the same range of friction but is on the heavy side. It is
> synthetic, at least I got that right. Not sure if it has detergent in yet
> but that is a must too I read. the 20/50 could damage or stop the ignition
> though because of its pressure rating. If bleeding does not start the
> engine I may need to change back to 10/40. I would think the 20/50 might
> be good for storing it over the winter. Once it has warmed up and gone
> through the gears or are people saying that will drag the gears and actually
> gum it up good?
> If I start it in neutral I do not think there is any pull forward but
> then again the battery was too low by that point anyway.
>
It probably doesn't matter much if you use 10w40 or 20w50. It's way more
important that you use the correct amount of oil.

--
Jamin
"Freedom costs a buck-oh-five"




--
Posted via a free Usenet account from http://www.teranews.com
 >> Stay informed about: What causes the bike to jump forward 2ft when starting up? 

On Sep 25, 3:31?pm, "Dave" wrote:

> I musta' misinterpreted what you said. A 20HP bike should be able to slip
> the clutch as well as a 100hp bike, just depends how much you have to pull
> the lever in to make it slip, no?

You can slip the clutch at 90 mph in 4th gear without touching the
lever if you have 100 HP and stock clutch springs, but you'll need to
use the lever on smaller engines.

The British GP racers started doing all this clutch slipping back in
the 1930's on their Norton Manxes. They needed a very tall first gear
so they wouldn't have to slow down too much for first gear corners.

But the Manxes were tuned for high RPM and the engine only produced
best power in a very narrow RPM range when the air intake horns and
the megaphone exhaust pipes were working together.

So the racers had to slip their clutches to get up into the range
where first gear was low engine to produce enough torque.
>
> Clutch slipping in corners must lead to some fairly short clutch lives.
> Friction plates are cheap though...

Clutch plates are a lot better nowadays.

Sets of clutch friction plates were part of the spares kit when a
professional road racer bought a production racing Yamaha, like a
TD-1, back in the early 1960's.

Racers also got spare pistons and rings and jets and sprockets and hot
and cold spark plugs and ignition points, etc in those days before you
could just run down to the sportbike emporium and buy anything you
needed.
 >> Stay informed about: What causes the bike to jump forward 2ft when starting up? 

"smn" wrote in message


> I have to bleed some oil first cause that definitely causes problems.
> I have the little window for oil level but do not know if the bike has to
> be upright or not.

Slow down, take a deep breath, and use your brain before your next post. Of
course it has to be upright, dipshit. Put it on the center stand. If you
don't have one, lean it against a wall.

Next, although the oil change and the clutch issue started at the same time,
many a mechanic has been screwed with statements like "that definitely
causes problems."

> Does slip the clutch mean changing gears without using the clutch
> because I can do that.

No slip the clutch means the clutch is slipping... it is failing to transfer
all available power from the engine to the transmission, i.e. the friction
of the clutch plates is being overcome by the torque of the engine. Any
vehicle with a manual transmission can switch gears without a clutch, most
truckdrivers don't use the clutch a whole lot when shifting they match the
engine RPM's to the gear and speed and slip it in.

> Thanks for all the help folks. You saved my engine most likely.
> The 20/50 is for high revving engines but then so is the 10/40. The
> former has the same range of friction but is on the heavy side. It is
> synthetic, at least I got that right. Not sure if it has detergent in
> yet but that is a must too I read. the 20/50 could damage or stop the
> ignition though because of its pressure rating. If bleeding does not
> start the engine I may need to change back to 10/40. I would think the
> 20/50 might be good for storing it over the winter. Once it has warmed up
> and gone through the gears or are people saying that will drag the gears
> and actually gum it up good?
> If I start it in neutral I do not think there is any pull forward but
> then again the battery was too low by that point anyway.

You really, really need to at the very least get your hands on a maintenance
manual, or bring the bike to a mechanic before you damage it. Most if not
all of what you state above is glaringly inaccurate, and anyone with the
vaguest understanding of the workings of a relatively modern internal
combustion engine would be able to see that. Find out what the recommended
oil is from the manufacturer and use it. Period. A helluva' lotta' thought
by the engineers went into determining which oil would work the best. The
wet clutch is designed for use with a particular grade of oil as are many
many other engineered parts. Don't second-guess them because of some
display at Wal-Mart which advertises oil "for high-revving engines".

Just out of curiosity, what logic led you to state "the 20/50 could damage
or stop the ignition though because of its pressure rating" ??? I ask
because my 7-year-old, who has no experience with the cause-and-effect of
mechanics and who asks a lot of questions trying to build appropriate mental
models of how things work, often comes out with bizarre statements like that
and I'd love to have an idea of where they come from.

How, exactly, would storing a bike with a different oil than what you run it
with help it in any way?


Dave S.
>
> Suzuki DR200
>
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"~" wrote in message

> On Sep 25, 11:04?am, "Dave" wrote:
>
>> No slip the clutch means the clutch is slipping... it is failing to
>> transfer
>> all available power from the engine to the transmission, i.e. the
>> friction
>> of the clutch plates is being overcome by the torque of the engine.
>
> Have you ever been to a 125cc GP race or a shifter kart race?
>
> The racers intentionally slip the clutch in slow corners to keep the
> engine in the power band.
>
> Multiplate clutches are designed to be slipped and operated at high
> rpm and may be oil-cooled or air-cooled.
>
> Shifter cart drivers never use the clutch for shifting gears, only for
> slipping on the starts and in slow turns.
>
I musta' misinterpreted what you said. A 20HP bike should be able to slip
the clutch as well as a 100hp bike, just depends how much you have to pull
the lever in to make it slip, no?

Clutch slipping in corners must lead to some fairly short clutch lives.
Friction plates are cheap though...
 >> Stay informed about: What causes the bike to jump forward 2ft when starting up?