What you describe is a lot like downshifting to too low a gear. The sudden engine braking will feel like the surge you described and the high compression big vee will certianly feel like the binders have been applied as the engine slows the bike. Any chance?

Otherwise, I'd be curious as to what the rpm's are when this happens since it's happened more then once. If it's in the dreaded 3500-3800 range, I'd wonder where your tps is calibrated. I hear the book says it should transition from low to high around 3500 but I've taken the advice of a member of another board and set mine to transition at around 2500.

jeff

 

The sudden engine braking will feel like the surge you described and the high compression big vee will certianly feel like the binders have been applied as the engine slows the bike. Any chance?


jeff

I'll post the same thing as I did a few months ago

Compression has absolutely noting to do with engine braking, if it did, why to I-4s with higher compression not engine brake as well?

fwiw, pulling vacuum thru closed throttle plates is what causes engine braking

 

That downshifting idea registered with me: I had a KLR - every once in a great while I'd hit a bump or something and it would radically slow (engine braking). Took me quite a while to figure out that where I was keeping my foot if I hit a bump just the right way I'd mash it down a gear.

It was VERY disconcerting when riding - easy to see how in the right (wrong, really) circumstance it could lead to a dismount.

Not saying that's your problem, tho - I don't know. Maybe sit on the bike and take a look at where you tend to keep your foot. I discovered on my KLR, the side of my boot would just graze the front of the shift lever.

 

Wow, that's scary! Glad to hear you're okay.

 

I'm gonna go with too low idle causing it to stall mid-turn, flopping him onto the ground, or if he was on the throttle through the turn, either popping it into a lower gear like Steve mentioned, or some other running issue that caused the engine to die or sputter.

Idle needs to be closer to 1300 to not mis-fire. That in itself may help, but without knowing the exact circumstances of the surge/hiccup/whatever it was, it's still anyone's guess.

 

I can't see that it is just a downshift. Varminter describes a very sudden acceleration followed by a very sudden deceleration. What explains the first part if it is a downshift error?

 

... a very sudden acceleration followed by a very sudden deceleration. ...

Good point.
<steve backs away from his previous post>

 

Varminter; Get the bike in to Suzuki, and leave it there till they figure it out. You have been real lucky, so far.:fineprint::yikes: I know, getting bucked off don't seem that lucky, but could have ended much worse. Any chance you can talk to the PO to see if they had this problem? Can you remember if you did anything to the bike just before this started?

 

Technically, the OP did not describe an "acceleration". What he describes as a "surge" may well be the sudden increase in RPM's following a downshift.

It's happened to me a few times, leaving my foot on the shifter, and just sneaking it into first.

What's more worrisome is the "hiccup" while slowing down, and stalling. (maybe this was such a "hiccup" too, just more pronounced). I've had these hiccups, starting after my TPS went bad (At least that's what I think it is).

I think the OP would be wise to have a good look at the TPS, and make sure that the throttle bodies are seated.

 

I certainly appreciate your feedback on this. I ride this way every day.From memory, the bike would have been in second, low rev's just relying on engine braking before I stopped at the junction. The bike gave a huge lurch, I suspect the engine died then caught again, then wham, I was off and sliding down the road. I'm hoping the bike shop comes up with an answer today. The bumps and bruises are much better too. Thanks heaps.

 

Nothing Wrong

There is nothing wrong with you bike. The throttle spring on the DL1000 is very strong. An abrupt release of the throttle entering a turn will dramatically decelerate the bike like a bucking bronco. It takes some getting used to.

 

In a Kiwi forum a suggestion was made that there is an issue with the engine being too lean causing a "cough". Anyone else experienced that?

 

My bike had this "cough" for a while and then began backfiring through the airbox. The Suzuki shop said it was running lean. I just got it out this past weekend and it seems to be running really well, even in the dreaded 3500 to 3800 rpm range. I've not had any coughs or backfires yet since getting it out

 

Quite simply... what do you do to initiate engine braking...

do you block the exaust like a diesel ?

no, you close the throttle and limit intake.... creating a vacuum, its as simple as that. the pistons aren't compressing anything cause nothing is sucked in

 

...creating a vacuum, its as simple as that. the pistons aren't compressing anything cause nothing is sucked in

Nothing is sucked in eh?

I'll ask again, do you have any idea how many litres of air per minute flow through your closed throttles? (Remember that the bike displaces 1000cc, and idles at 1400 some rpm; I strongly encourage you to do the math)

If you had a perfect vacuum between your throttle plates and your piston on the intake downstroke, two things would happen:

Your engine would not be able to idle (no air)
Your throttle valve would get sucked into the engine, or your connecting rod would snap.

The idea that engine braking is due to vacuum is risible. If Wiki is your source, maybe someone should go fix that entry...

Instead of believing wiki-garbage, you should try hitting your killswitch and see that you still have engine braking at WOT (and that in fact the throttle opening does not affect engine braking). It's ridiculously easy to try, and would set your mind at ease immediately. Unless of course that would shatter your faith in wiki and the subsequent years of therapy would be too expensive.

You still haven't explained how this vacuum theory explains your claim that i4 engines have less engine braking than v-twins. Do they have leaky throttle plates?

 

I hate to break into this fascinating discussion, but I think I may have the answer.

Quote by Varminter
I certainly appreciate your feedback on this. I ride this way every day.From memory, the bike would have been in second, low rev's just relying on engine braking before I stopped at the junction. The bike gave a huge lurch, I suspect the engine died then caught again, then wham, I was off and sliding down the road. I'm hoping the bike shop comes up with an answer today. The bumps and bruises are much better too. Thanks heaps.

...the bike would have been in second, low rev's....The bike gave a huge lurch, I suspect the engine died then caught again, then wham.....

I'm going to guess that you just killed the motor with low revs. It will 'lock up and die' and then recover. I'd say try using the clutch earlier (freewheel) and front brake to get to the stop. If you get the rev's under idle speed, even for an instant, it could happen.

How do I know that? Yep, every now and again I'll forget to pull the clutch.

Back to the point of the intermediate discussion.
An internal combustion engine is an air pump. No more, no less. More air=more horse power, less air=less horsepower.

 

…Wow, all this semi-science debate and the OP was only looking for practical help.

I am going to guess what a couple have already stated is the cause. Maybe in combination: An engine not at full temperature, slight lean fuel running condition, an idle set just a little too low, engine revs slightly too low (or a gear too high) for the situation. Roll the throttle off for the corner and the engine wanted to die so the ECU compensates to speed it back up, then re-compensates to match the throttle position. Creates an accelerate/decelerate situation. Seems to me should check the TPS, throttle body synchronization and idle speed. But, it is only a guess.

 

:iamwithstupid::ban:


I want my 5 minutes back.

 

Randy, I think that we must be misunderstanding eachother...

I really wish you stopped with your apples to oranges thing and just tried it out... I've tried explaining it (maybe I did a bad job), but you haven't explained anything. you just keep repeating the same (wrong) thing.

A running engine will engine brake more with the throttle closed, sure.
It will also engine brake with the throttle open slightly less than what is needed to sustain a constant speed.
Actually, your running engine will engine-brake at WOT as well if the rev limiter kicks in. You can try that one out too. (edit, oops, the strom's limiter alternates spark, and doesn't actually completely shut it down, so it rapidly alternates between braking and power)

All these observable braking effects are due to the compression stroke, and none of them depend on the throttle being shut, or on vacuum.

Please, just go try it out, than explain to yourself why it behaves the way it does...

 

Randy, I think that we must be misunderstanding eachother...

I really wish you stopped with your apples to oranges thing and just tried it out... I've tried explaining it (maybe I did a bad job), but you haven't explained anything. you just keep repeating the same (wrong) thing.

A

when you hit the kll switch, you are changing the conditions, you now longer have a spark to ignite he gasses you have just compressed there will be no combustion to force the piston down

its not a valid comparison to a running engine

removing the spark/combustion is another way of making the engine slow, but not one I'd recommend, if you cut the ignition, anything you do to the throttle will have no effect, the motors going to try stopping, when you shut your ignition off in neutral, does your engine continue to spin

Have you ever driven a car with vacuum vipers..... probably not, I haven't seen em since the 50's, when you let off the gas, the wipers go fast, when you step on the gas, they slow down, and if you floor it, they will stop

 

You're totally confused (about this particular principle), I give up...

 

Called in to the bike shop on Saturday, story is they are going to check it on the diagnostic machine (lets hope it has the answers) from what I can pick up, (and I'll admit here that apart from the theory I don't have practical experience on motors) it would seem there is a problem with the engine management system and the low down rev's are too low and lean and likely to have the bike stall. It did cut out a few times but I've recently increased the tick over. The last lurch it did, and looking back it's done it at least half a dozen times, was on a ride with the wife as pillion, after 200K's we were back in town and turning right at the lights, almost crawled to a stop when the lights changed, into first at the traffic moved and again came that 'lurch', the boss thought we were going to drop it but it was a small one. Not like the last one!!

Got several bruises, the one on my foot is a doosie, glad I never wear sneakers, I'd have been a hospital case for sure.

You can continue your fight now.:thumbup:

 

Varminter; To help us, help you in the future, avoid words like lurch and surge. They are not definitive enough. (not scientific) The word surge is defined (by me) as, sudden increase in acceleration as near as I could make out with respect to your situation. The word lurch is defined as, sudden uncontrolled movement. Both fit the situation, but don't specifically tell us what the engine was doing.:fineprint: I hope this comes across right, as I'm just trying to help. Best of luck with the shop, let's hope they sort it out soon. Post the outcome if you can.

 

Lol Bob.

What word would you have used to describe his symptom?

I propose "stumburpledump".

 

+1 Duck.:green_lol::green_lol: For my case it would be "Lob a Bob" :yikes: For you it could be "Buck a Duck" :green_lol: For Varminter, probably something way more serious like :jawdrop::yikes::furious:

 

Please......send PM's to eachother instead of pissing about it here.:thumbdown: I have a 1400cc high compression inline 4 that has much better engine braking then my old vtwin 1000 Strom "as well has better braking period", so how the hell is that? Please send me a PM with ya'lls vast knowledge. Eventhough though I could give a rats ass.

 

G'day, mate of mine came across a service bulletin from American Suzuki Motor Corporation. It specifically mentions a reported problem. Quote: we have found a number of customers who own DL1000 2004-2005 and early 2006 models may possibly experience a surging or hesitation under certain operating conditions. Most noticeable at steady throttle settings in the low rpm range. Now my bike purports to be a 2008 but who knows how long it was in the showroom and also I'm the third owner. Sounds like my problem though. Watch this space.

 

Varminter; I think the surging they are referring to is a much milder form of surge, so mild in fact that most people won't notice it until it's pointed out to them. (it can become very noticable over time and many large displacement twins with fuel injection seem to suffer this malady as they age and fuel control devises get out of sync. notably, BMW.) If this is your problem, then some thing(s) is way out of wack.:jawdrop: Keep us updated.

 

Mine was an 05 with the surging and hesitation noted in that bulletin. I assure you, when I first got the bike, if it had happened at the perfect time, it could've ejected me from the seat.

I'm very interested to hear how this turns out.

 

I know this is of no help now that it has happened, but I developped a habit of always having my clutch covered. The habit came from old unpredicatble bikes.
I also often feather the clutch and the back brake during slow speed maneuvres (to avoid a stall or a tire spin).

I'm guessing the people that never had a problem are experienced riders (becasue they had old ratty unpredictable bikes) and do the same as me without even noticing.

 

You've gotta be a bloody Kiwi with a reply like that:thumbup: