I have a DL650K5 with about 900 mi. on it and It seems to be surging a little more lately when holding the throttle at a steady speed. Of course this is more noticeable when in the lower gears at between 3200 to 4000 rpm's. I usually just shift to a higher gear so there is more of a load on the engine, but I don't want to lug the engine too much. I have read that this is a problem for some on the 1000's but hadn't heard about it on the 650's. Anyone else have this?

3200 to 4000rpm is what I would consider "lugging" the engine.

 

CTW, You're right, That didn't make sense. I meant to say that I have to lug it at around 3000 to 3800 to avoid the surging. For instance, I lug it at 3000 rpm's in fourth gear at 30 mph when going through town to prevent the surging. If I go down into 3rd, it brings the rpm's up and the surging happens more. It happens at slow speeds when there is a very light load on the engine and running at 3800 to 4800 rpm's or so. I read in another post that the FI can be remapped to help this.

I recently put Mobil premium in it and I wonder if that is the problem. Maybe the premium gas at that station is old because it's just too expensive and everyone is running the cheaper stuff?

 

CTW, You're right, That didn't make sense. I meant to say that I have to lug it at around 3000 to 3800 to avoid the surging. For instance, I lug it at 3000 rpm's in fourth gear at 30 mph when going through town to prevent the surging. If I go down into 3rd, it brings the rpm's up and the surging happens more. It happens at slow speeds when there is a very light load on the engine and running at 3800 to 4800 rpm's or so. I read in another post that the FI can be remapped to help this.

I recently put Mobil premium in it and I wonder if that is the problem. Maybe the premium gas at that station is old because it's just too expensive and everyone is running the cheaper stuff?

 

I've never had surging with mine and it currently has 4k on it.
It could be the premium fuel, there are some on here who claim that the bikes don't run well on premium. I've never put premium in mine, its supposed to run regular and seems to do well on it so thats what I do.
I would run the premium as close to out as you can, fill it with regular and see what it does after a couple of tanks. If not I would synch the throttle bodies. If it wasn't cured by then I'd talk with the dealer.

 

Does it pull smooth under hard acceleration at low RPM?

 

Jack,
No problem with my DL650K5. I have about 4K on the odometer and never used premium fuel in it. Unless an engine is designed with high grade fuel in mind it has no positive affect on it and sometime the opposite is true.

Wingman

 

I put some premium in mine, I had it in a can at home and it was there, I was there, so I put it in the bike. It did not like it. I am just about through the tank, no real major issues, but the bike is just not as smooth as it was with pure regular 87 R+M/2 in it. I will never do that again. Otherwise, I've never had any issues with surging or inconsistent idle / cruising / WOT.

 

CTW, You're right, That didn't make sense. I meant to say that I have to lug it at around 3000 to 3800 to avoid the surging. For instance, I lug it at 3000 rpm's in fourth gear at 30 mph when going through town to prevent the surging. If I go down into 3rd, it brings the rpm's up and the surging happens more. It happens at slow speeds when there is a very light load on the engine and running at 3800 to 4800 rpm's or so. I read in another post that the FI can be remapped to help this.

I recently put Mobil premium in it and I wonder if that is the problem. Maybe the premium gas at that station is old because it's just too expensive and everyone is running the cheaper stuff?

For me at least even 3800 to 4800 is lugging it. Bring the Rs up over 5K and you shouldn't have a problem.

I've never used anything but 87 octane and suffer ZERO surging.

my .02 worth

 

thanks for the advice guys,

Mattman, it is smooth under acceleration throughout the rev range, even low rpm's.

CTW, I'll get her in the 5000+ range and see what happens.

The only reason I tried premium is that I thought I heard a pinging or gurgling under acceleration. It may have been my brains vibrating inside my skull though :lol: . It's hard to hear it with the wind and all. It could be a sound that is characteristic of the bike too.

I'll use up the premium and put regular in it again and report back with the results. Another excuse to go riding!

 

Keep it above 4,000 rpm and she will be happy.

 

The only reason I tried premium is that I thought I heard a pinging or gurgling under acceleration. It may have been my brains vibrating inside my skull though :lol: . It's hard to hear it with the wind and all. It could be a sound that is characteristic of the bike too.

I've heard that sound to and I believe it's either suspension noise, wind noise or possibly both. Reason I say that is when I bring my head out of the airflow and close to the engine, the noise disappears.

Far as the surging thing goes, I get a tiny bit of surging when I keep it at a steady pace below 4K RPM. Past 4K, it's fine. I use 87 octane fuel.

 

Far as the surging thing goes, I get a tiny bit of surging when I keep it at a steady pace below 4K RPM. Past 4K, it's fine. I use 87 octane fuel.

Same here. Slow roll on, keeping the throttle steadily advancing from ~3K to ~4K, the bike feels like I am riding on rough pavement. The slow roll on from stop to 3K is smooth as well as past ~4K with no change in throttle input. I will probably mention it to the dealer and see what they think, I am torn on ignoring it b/c I do a lot of city traffic driving and sometimes can't help but sit there in that range.

 

I've been getting some surging on mine exactly as you describe in the lower gears and when giving small throttle inputs. This is usually most noticeable when going through a town with a low speed limit like 25 or 30 where I have to maintain a constant throttle. I usually upshift to make the surging less of a problem. I have used 87 octane fuel since day one so that's not it for me. I think it may be time for a TBS. I've noticed it for a while but figured it wasn't too bad so I just put it off. It also seems like I'm getting a little more vibration coming through the bars. I've got a TwinMax left over from my BMW days so I'm hoping I can just use that to get a good sync. :wink:

 

One thing you may want to consider and note, particularly if you're trying to describe this symptom to your mechanic, is the throttle position when the symptom occurs. RPM really has little to do with it. Such as 1/8, 1/4, 1/2 or whatever throttle, obviously this is your best estimate, but that is the important information when tuning carbs or efi. (Certainly load is important, too.)

 

I think I figured it out. The following items have shown me that they cause sensitivity to smoothness and can create a feeling of surging:

1. Chain tension. If it is too loose, you get this winding up / unwinding effect through the drive train and it translates into a surging feeling. The engine is consequently being loaded / unloaded and this might feel like surging. I've found this bike especially sensitive to chain tension.

2. Throttle cable tension. If there is too much slack, it becomes difficult to roll on the throttle nice and gentle to get the exact amount of input you are requesting. You end up opening it too abruptly. Due to the abundant amounts of torque associated with this engine, this is also a sensitive spot.

 

I think I figured it out. The following items have shown me that they cause sensitivity to smoothness and can create a feeling of surging:

1. Chain tension. If it is too loose, you get this winding up / unwinding effect through the drive train and it translates into a surging feeling. The engine is consequently being loaded / unloaded and this might feel like surging. I've found this bike especially sensitive to chain tension.

How often do you find the chain tension has loosened up from spec?

 

Not often. I only had to adjust it once so far (2000 miles), I had just noticed that it was waaaay more surgy when it was out of spec. After the adjustment, it was alot smoother. This o-ring chain should be pretty bullettproof.

 

Not often. I only had to adjust it once so far (2000 miles), I had just noticed that it was waaaay more surgy when it was out of spec. After the adjustment, it was alot smoother. This o-ring chain should be pretty bullettproof.

I've adjusted my chain twice now and it's at 4k so I dunno. I really think mine is a TBS issue and I just haven't gotten brave enough to try it.

 

The place where I have this problem is when you are not accelerating and not engine braking either. It's that in between place where you are not really giving it hardly any throttle at all. Just enough to keep a steady speed in 3rd gear. That's when it "searches" or "bucks" or "surges". When I accelerate it is fine.

Maybe this is normal and I'm not? :shock:

Maybe I'm being overly fussy :?:

Going through town at a steady 30mph at 3000 rpm seems to be the smoothest at that speed.

RubberDown, let me know how you make out.

TheTwins, thanks I'll try adjusting the chain to the tighter side of spec and adjust the throttle cable to the tighter side too. I'll report back with my findings.