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Froggy
Posted on Friday, August 14, 2009 - 05:19 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Does the slipper clutch prevent this from working? I went to leave my house, the driveway is a decent hill, and being that the bike was already warmed up I wanted to give it a practice try in case like I left the lights on or something and killed the battery. Down the hill I went, I believe in 3rd, gently release the clutch and it slowed me down fast, but no start. I didn't want to damage anything so I didn't try it again. I hit the starter like normal and took off. I know my XB12 can be a pain if you don't catch it right, but I figured I would ask on here first about my CR. : )
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Steeltech
Posted on Friday, August 14, 2009 - 10:40 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

you don't gently bump start a high compression bike. what you would have to do is stand up on the pegs and hold the clutch in. Roll down the hill till you get maybe around 10 mph. In one swift motion sit down on the bike suddenly while at the same time dumping the clutch. You have to apply weight to the rear wheel for traction and you have to suddenly force the engine to turn over to get over the compression to fire. As long as you have enough juice in the battery to fire the spark plugs it should start. I was thinking about trying it, I just never did. Remember...you are fighting 12:1 compression of 1125cc, so that needs a bit more force to turn over
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Gregtonn
Posted on Friday, August 14, 2009 - 11:13 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

The 1125 "slipper clutch" works via the increase in intake vacuum during engine deceleration.
So if your engine isn't running...

G
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Xl1200r
Posted on Friday, August 14, 2009 - 11:22 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Remember...you are fighting 12:1 compression of 1125cc, so that needs a bit more force to turn over

Also remember that you're dealing with a short-stroke engine, so you don't really need *that* much force. If the engine compression is what stopped him, he would have gone over the bars.

So if your engine isn't running...

I'll finish it - you have no vacuum to pull back on the clutch plate.

Frogs - when it slowed you down, did you feel the engine pumping at all? I'm guessing not. I would try it in 4th gear next time - I can't imagine the clutch wouldn't be able to grab hard enough.
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Froggy
Posted on Friday, August 14, 2009 - 11:40 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I honestly don't recall if it was pumping or not, will try it again. : )
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Gregtonn
Posted on Saturday, August 15, 2009 - 01:32 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Mark,
Good answer.
Before I get beat up too badly I'll modify my statement about the increase in intake vacuum.
It is the result of closing the throttle plates while the engine is pumping.
At slow pumping speeds there is not enough vacuum to activate the slipper.

G
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Bobup
Posted on Tuesday, August 18, 2009 - 01:16 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

had to bump start a couple of times back spring of last year, prior to having a "fix" for the battery drainage. glad that one was resolved with just a re-flash, it took 3 people to do a bump start on level ground

(Message edited by bobup on August 18, 2009)
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Lovedabueller
Posted on Tuesday, August 18, 2009 - 01:29 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Can you bumpstart a fuel injected engine?
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Froggy
Posted on Tuesday, August 18, 2009 - 01:55 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Due to the great badweb crash, several posts on here are gone. I shall repost them in a second.


Lovedabueller, yes. I bump start my XB12 more times than I start with the button.
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Froggy
Posted on Tuesday, August 18, 2009 - 01:57 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

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Buell Motorcycle Forum: 1125R Superbike Board: Bump starting?
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Posted by Bigblock on Saturday, August 15, 2009 - 01:51 pm:

3 rd prolly won't do it, 5 or 6th gear even might be necessary



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Buell Motorcycle Forum: 1125R Superbike Board: Bump starting?
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Posted by Crowley on Saturday, August 15, 2009 - 02:07 pm:

I used to bump start my NorVin on the flat by myself regularly before
having the magneto armature rewound. The trick is to roll the motor
back against compression on the rear cylinder and let the inertia in
the flywheels do the work for you.
Any of you guys kick up big singles/twins - same idea.
My 1947 JAP/Enfield race bike (700cc single) runs on a Methanol
burning 16:1 comp ratio and there's no retard on the Mag. A procedure
has to be followed to kick it up. I've said to a few people, if you
can kick start it , you can have it. Some have walked away limping



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Buell Motorcycle Forum: 1125R Superbike Board: Bump starting?
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Posted by Ccryder on Saturday, August 15, 2009 - 05:27 pm:

My 1st bike was a 500cc Norton single. It had left me limping 1-2
times. It also threw me over the bars into the garage door and stuck
my helmet through one of the panels. Just make sure you get the timing
close.

I was never one to be able to run, jump (side-saddle) and dump the
clutch. I had to throw my leg over, not side saddle.

At least 2nd will be required, maybe 3rd.

Later
Neil S.



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Buell Motorcycle Forum: 1125R Superbike Board: Bump starting?
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Posted by Froggy on Saturday, August 15, 2009 - 05:37 pm:

I got it to start! This thing isn't easy, Out of a handful of
attempts, the only one that worked was quickly letting out the clutch
at 30ish mph in 6th gear. Any faster would make the tire skid, any
slower would make it come to a dead stop fast. The bike makes a loud
whine when doing it, doesn't sound healthy.



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Buell Motorcycle Forum: 1125R Superbike Board: Bump starting?
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Posted by Bigblock on Saturday, August 15, 2009 - 10:31 pm:

There ya go...



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Rockstarblast1
Posted on Tuesday, August 18, 2009 - 04:56 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

iv done it once... goin down my street i hit the cut off swich and was coasting in gear as soon as i flipped the swich back on it fired right back up
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Froggy
Posted on Tuesday, August 18, 2009 - 04:57 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Thats not bump starting as the engine was still spinning.
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Slypiranna
Posted on Tuesday, August 18, 2009 - 09:01 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

No, not recommended on the 1125 series, IMO.
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Slypiranna
Posted on Tuesday, August 18, 2009 - 09:02 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

...there is a little starter button on the right side handle bar that works great when you have battery voltage...

...if no battery voltage, charge and/or jump.
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Zac4mac
Posted on Tuesday, August 18, 2009 - 11:32 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Gotta agree with Monty on this.
Dunno how much slack is in the cam chain but...
Loretta is noisy until the chain tensioner pumps up.

Possible valve-piston uglies?

Z
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Bigblock
Posted on Wednesday, August 19, 2009 - 01:39 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

That was strange, what's happening to some of our posts?
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