Engine braking?
-
- Member
- Posts: 32
- Joined: 11:18 pm Mar 05 2010
- Country:
Engine braking?
I was jut reading on a different post about something else, when some one throws that you shoudnt engine brake. I use the engine alot to slow me down on hills and whenever. Am i harming this bike by doing so??
All coiled up ready to strike
- Indawoods
- Creator and Founder
- Posts: 9951
- Joined: 09:59 am Jun 12 2003
- Country:
- Location: Midwest
What post? I engine brake.... always have.
*** Administrator //***
****'95 KDX 200/****
"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
****'95 KDX 200/****
"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
- jad628
- Supporting Member
- Posts: 111
- Joined: 08:52 am Jan 05 2011
- Country:
- Location: Lake Norman area, NC
- rbates9
- Supporting Member II
- Posts: 3164
- Joined: 06:07 pm Apr 27 2010
- Country:
- Location: UPSTATE New York
The only possible issue that could arise (that I can think of) is if you "engine brake" too fast for too long I could see how you might be able to run the cylinder dry due to the engine rpm's being high and the throttle closed not allowing the fuel oil mix to run in to the cylinder and lube every thing.
I also engine brake when I ride, not sure why but I picked up the habit of clutching or holding the throttle open a little. I'm not sure why I do either one but I do.
I also engine brake when I ride, not sure why but I picked up the habit of clutching or holding the throttle open a little. I'm not sure why I do either one but I do.
- scheckaet
- KDXRider.net
- Posts: 3740
- Joined: 12:09 am Nov 10 2005
- Country:
- Location: edmond oklahoma
+1rbates9 wrote:The only possible issue that could arise (that I can think of) is if you "engine brake" too fast for too long I could see how you might be able to run the cylinder dry due to the engine rpm's being high and the throttle closed not allowing the fuel oil mix to run in to the cylinder and lube every thing.
02 KX 200 hybrid: RB head and carb
Sold ☹ DRZ 400 SM
bike build: http://www.kdxrider.net/forums/viewtopi ... ike+stable
bike profile http://www.kdxrider.net/forums/viewtopi ... 0709#30709
newb info: http://www.kdxrider.net/forums/viewtopi ... 57#p117919
jetting guide: http://www.kdxrider.net/forums/viewtopi ... 105&t=1156
Sold ☹ DRZ 400 SM
bike build: http://www.kdxrider.net/forums/viewtopi ... ike+stable
bike profile http://www.kdxrider.net/forums/viewtopi ... 0709#30709
newb info: http://www.kdxrider.net/forums/viewtopi ... 57#p117919
jetting guide: http://www.kdxrider.net/forums/viewtopi ... 105&t=1156
-
- Member
- Posts: 643
- Joined: 09:05 pm Sep 07 2010
- Country:
- Location: Houston, TX
- Julien D
- KDXRider.net
- Posts: 5858
- Joined: 07:53 pm Nov 07 2008
- Country: USA
- Contact:
Yep. It's recommended on long descents to keep the clutch pulled and give a little throttle once in a while to shoot some lube into the cylinder.
Also, if you had it pinned on a long stretch of open road, and then you slow up by shifting down through the gears, that can cause big problems. A little engine braking on a brief downhill is not going to destroy the engine though.
Also, if you had it pinned on a long stretch of open road, and then you slow up by shifting down through the gears, that can cause big problems. A little engine braking on a brief downhill is not going to destroy the engine though.
- OLHILLBILLY
- Supporting Member I
- Posts: 286
- Joined: 08:34 pm Feb 10 2009
- Country:
- Location: S. W. Missouri
I usually pull the clutch in on downhills. 2 stroke doesn't have much for engine braking anyway, so to avoid any chances of the "no fuel/oil" problem, I've just gotten in the habit of free wheeling on some decel and most descending.
2004 KDX 200.. Coupla mods
2009 KX250F.. Track Star
2007 Hayabusa.. Street Madness
2009 KX250F.. Track Star
2007 Hayabusa.. Street Madness
- Mr. Wibbens
- KDXRider.net
- Posts: 4884
- Joined: 02:57 am Nov 07 2004
- Country:
- Location: Playing in the Poison Oak
- Contact:
If there's no fuel/oil, how's the motor running?
Warning! This member tends to use sarcasm as a regular form of communication. If a post seems offensive, before you panic and fly off the handle, re-read the post and imagine it being said with a sideways grin.
((Bike Profile))
((Pics))
FIVE OUT OF FOUR PEOPLE DONUT UNDERSTAND FRACTIONS
((Bike Profile))
((Pics))
FIVE OUT OF FOUR PEOPLE DONUT UNDERSTAND FRACTIONS
- OLHILLBILLY
- Supporting Member I
- Posts: 286
- Joined: 08:34 pm Feb 10 2009
- Country:
- Location: S. W. Missouri
-
- Member
- Posts: 23
- Joined: 11:54 am May 03 2010
- Country:
- Location: Redwood City, CA
- Mr. Wibbens
- KDXRider.net
- Posts: 4884
- Joined: 02:57 am Nov 07 2004
- Country:
- Location: Playing in the Poison Oak
- Contact:
The motor is still running when you are engine breaking
Otherwise the rear wheel would be locked up no?
Warning! This member tends to use sarcasm as a regular form of communication. If a post seems offensive, before you panic and fly off the handle, re-read the post and imagine it being said with a sideways grin.
((Bike Profile))
((Pics))
FIVE OUT OF FOUR PEOPLE DONUT UNDERSTAND FRACTIONS
((Bike Profile))
((Pics))
FIVE OUT OF FOUR PEOPLE DONUT UNDERSTAND FRACTIONS
- Tedh98
- Supporting Member II
- Posts: 1576
- Joined: 01:08 pm Mar 20 2009
- Country:
- Location: Atlanta, Georgia
- Contact:
- Tedh98
- Supporting Member II
- Posts: 1576
- Joined: 01:08 pm Mar 20 2009
- Country:
- Location: Atlanta, Georgia
- Contact:
If you wind out the engine to 9K rpm and then cut the throttle but don't pull in the clutch, the engine is spinning at 9K but only has enough fuel entering the engine to sustain idle, which shouldn't be enough to properly lubricate.
But when you pull in the clutch, the rpm's drop and the rpm's then better match the fuel entering the engine.
At least that is how I look at it.
- Mr. Wibbens
- KDXRider.net
- Posts: 4884
- Joined: 02:57 am Nov 07 2004
- Country:
- Location: Playing in the Poison Oak
- Contact:
Thats a little more extreme than typical engine braking dontcha think?Tedh98 wrote:If you wind out the engine to 9K rpm and then cut the throttle but don't pull in the clutch, the engine is spinning at 9K but only has enough fuel entering the engine to sustain idle, which shouldn't be enough to properly lubricate.
But when you pull in the clutch, the rpm's drop and the rpm's then better match the fuel entering the engine.
At least that is how I look at it.
Warning! This member tends to use sarcasm as a regular form of communication. If a post seems offensive, before you panic and fly off the handle, re-read the post and imagine it being said with a sideways grin.
((Bike Profile))
((Pics))
FIVE OUT OF FOUR PEOPLE DONUT UNDERSTAND FRACTIONS
((Bike Profile))
((Pics))
FIVE OUT OF FOUR PEOPLE DONUT UNDERSTAND FRACTIONS
- Tedh98
- Supporting Member II
- Posts: 1576
- Joined: 01:08 pm Mar 20 2009
- Country:
- Location: Atlanta, Georgia
- Contact:
Sure, most of the time my 9K example is extreme. But what is typical?
But if you get going downhill in the wrong gear you get the rpm's up pretty quickly.
One of the places we go riding has a drag strip, I hear a lot of guys wind up through the gears and then hear them chop the throttle and engine brake down to 10 mph. My son had the nasty habit of doing this when he first started riding.
I guess the problem really becomes how many rpm's and for how long can a motor spin beyond a given level of fuel before the oil can't provide protection?
But if you get going downhill in the wrong gear you get the rpm's up pretty quickly.
One of the places we go riding has a drag strip, I hear a lot of guys wind up through the gears and then hear them chop the throttle and engine brake down to 10 mph. My son had the nasty habit of doing this when he first started riding.
I guess the problem really becomes how many rpm's and for how long can a motor spin beyond a given level of fuel before the oil can't provide protection?
- OLHILLBILLY
- Supporting Member I
- Posts: 286
- Joined: 08:34 pm Feb 10 2009
- Country:
- Location: S. W. Missouri
Anytime the throttle is closed and the engine is turning above idle RPM, there is "insufficient" (that's probably the word I should have used instead of "no") fuel/oil coming into the motor to lubricate the bottom end at that rate of motion. There is enough residual oil on the bearings to last for a period of time. How long that period of time is, is what your comfortable with.Mr. Wibbens wrote:Thats a little more extreme than typical engine braking dontcha think?Tedh98 wrote:If you wind out the engine to 9K rpm and then cut the throttle but don't pull in the clutch, the engine is spinning at 9K but only has enough fuel entering the engine to sustain idle, which shouldn't be enough to properly lubricate.
But when you pull in the clutch, the rpm's drop and the rpm's then better match the fuel entering the engine.
At least that is how I look at it.
Kinda like the 60:1 mix folks, if your comfortable with it, hey.. it's yours.
2004 KDX 200.. Coupla mods
2009 KX250F.. Track Star
2007 Hayabusa.. Street Madness
2009 KX250F.. Track Star
2007 Hayabusa.. Street Madness
- Mr. Wibbens
- KDXRider.net
- Posts: 4884
- Joined: 02:57 am Nov 07 2004
- Country:
- Location: Playing in the Poison Oak
- Contact:
I've never worried about it yet, and we actually have hills to ride down here
Warning! This member tends to use sarcasm as a regular form of communication. If a post seems offensive, before you panic and fly off the handle, re-read the post and imagine it being said with a sideways grin.
((Bike Profile))
((Pics))
FIVE OUT OF FOUR PEOPLE DONUT UNDERSTAND FRACTIONS
((Bike Profile))
((Pics))
FIVE OUT OF FOUR PEOPLE DONUT UNDERSTAND FRACTIONS
- SS109
- KDXRider.net
- Posts: 5796
- Joined: 05:11 am Aug 23 2009
- Country: USA
- Location: Tucson, AZ, USA
- Contact:
I read some where, can't remember where, a 2T engine holds oil in the lower part of the crankcase that has fallen out of suspension. That oil is then "splashed" onto the crank bearings and even up to the piston pin. So, oil in suspension is not the only lubrication the bottom end receives.
Youtube Channel: WildAzzRacing
AZ State Parks & Trails OHV Ambassador - Trail Riders of Southern AZ
Current KDX: '98 KDX220
Old KDX: '90 KDX200 -White/Blue
'11 GasGas EC250R
AZ State Parks & Trails OHV Ambassador - Trail Riders of Southern AZ
Current KDX: '98 KDX220
Old KDX: '90 KDX200 -White/Blue
'11 GasGas EC250R
- rbates9
- Supporting Member II
- Posts: 3164
- Joined: 06:07 pm Apr 27 2010
- Country:
- Location: UPSTATE New York
I have not heard that, not that I'm arguing that. But say you are going down a very long down hill, how long would that oil stay in there?SS109 wrote:I read some where, can't remember where, a 2T engine holds oil in the lower part of the crankcase that has fallen out of suspension. That oil is then "splashed" onto the crank bearings and even up to the piston pin. So, oil in suspension is not the only lubrication the bottom end receives.
I belive that this is one of those personal preference type things. Could it hurt your engine? Yes. Will it destroy your engine the first time? No. I would have to say that it greatly depends on how long, how fast the engine is turning and what the oil mix is.