Author |
Message |
Froggy
| Posted on Friday, August 14, 2009 - 05:19 pm: |
|
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. |
Steeltech
| Posted on Friday, August 14, 2009 - 10:40 pm: |
|
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 |
Gregtonn
| Posted on Friday, August 14, 2009 - 11:13 pm: |
|
The 1125 "slipper clutch" works via the increase in intake vacuum during engine deceleration. So if your engine isn't running... G |
Xl1200r
| Posted on Friday, August 14, 2009 - 11:22 pm: |
|
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. |
Froggy
| Posted on Friday, August 14, 2009 - 11:40 pm: |
|
I honestly don't recall if it was pumping or not, will try it again. |
Gregtonn
| Posted on Saturday, August 15, 2009 - 01:32 am: |
|
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 |
Bobup
| Posted on Tuesday, August 18, 2009 - 01:16 pm: |
|
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) |
Lovedabueller
| Posted on Tuesday, August 18, 2009 - 01:29 pm: |
|
Can you bumpstart a fuel injected engine? |
Froggy
| Posted on Tuesday, August 18, 2009 - 01:55 pm: |
|
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. |
Froggy
| Posted on Tuesday, August 18, 2009 - 01:57 pm: |
|
-------------------------------------------------- ---------- Buell Motorcycle Forum: 1125R Superbike Board: Bump starting? -------------------------------------------------- ---------- 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 -------------------------------------------------- ---------- -------------------------------------------------- ---------- Buell Motorcycle Forum: 1125R Superbike Board: Bump starting? -------------------------------------------------- ---------- 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 -------------------------------------------------- ---------- -------------------------------------------------- ---------- Buell Motorcycle Forum: 1125R Superbike Board: Bump starting? -------------------------------------------------- ---------- 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. -------------------------------------------------- ---------- -------------------------------------------------- ---------- Buell Motorcycle Forum: 1125R Superbike Board: Bump starting? -------------------------------------------------- ---------- 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. -------------------------------------------------- ---------- -------------------------------------------------- ---------- Buell Motorcycle Forum: 1125R Superbike Board: Bump starting? -------------------------------------------------- ---------- Posted by Bigblock on Saturday, August 15, 2009 - 10:31 pm: There ya go... -------------------------------------------------- ---------- |
Rockstarblast1
| Posted on Tuesday, August 18, 2009 - 04:56 pm: |
|
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 |
Froggy
| Posted on Tuesday, August 18, 2009 - 04:57 pm: |
|
Thats not bump starting as the engine was still spinning. |
Slypiranna
| Posted on Tuesday, August 18, 2009 - 09:01 pm: |
|
No, not recommended on the 1125 series, IMO. |
Slypiranna
| Posted on Tuesday, August 18, 2009 - 09:02 pm: |
|
...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. |
Zac4mac
| Posted on Tuesday, August 18, 2009 - 11:32 pm: |
|
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 |
Bigblock
| Posted on Wednesday, August 19, 2009 - 01:39 am: |
|
That was strange, what's happening to some of our posts? |
|