Hi guys,

I have a 2006 S2R1000 with 1300km's.
The question is: from 3000 rpm to 4000 rpm the engine rattles and struggles, after that its smooth, why?
Is this related to the O2 sensor and would go away by switching to Termi kit?
When I took the bike for the 1k service the guy told me this is normal with V2's...

Cheers,
Slick

If its rattleing and struggling while  your trying to accelerate from 3k to 4k, yes its normal, not so much a flat spot, just a bad spot to be trying to throttle through without going down another gear. if you are holding it steady in that rpm range, and its doing that, no its not normal. (but it could just be your throttle hand not being steady).

Solution: Change your final drive ratio via front or rear sprocket.

Good point He Man. I don't have any issues with that on my S2R.

+1 on He Man's explanation.  I try and accelerate so that when I shift into the next gear up, the bike starts that gear around 3.5-4k rpms.  Anything under that and you will get your "flat spot" where the engine just doesn't have the umph it needs to move you and the bike.  

And yes, getting the Termi system will probably help immensely.  A lot of that stuttering in lower revs comes from air restriction going into your air box and exhaust restriction leaving your cans.  Once you get into higher revs, the air/fuel ration evens out a bit (due to a higher air flow) and the bike runs more efficiently.  I have an 05 S2R and have the same problem at times, you just learn to rev around it.  Different gear ratio would help too.

Ok great explanations, thanks.
I had the impression I should not let it under 3k, so now I will adjust to 4k
One other thing, shall I let it run on stand untill the oil temp changes or shall I ride it? If ride in what rpm range shall I ride until what temps?

i let it run while i put on my riding gear, and then take it easy until the oil temp comes up


edit: for more response on this, try moving the post over to the tech section. some of the best tech folks hardly ever peak out of there.

Quote from: slick on September 30, 2008, 10:42:36 AM
Ok great explanations, thanks.
I had the impression I should not let it under 3k, so now I will adjust to 4k
One other thing, shall I let it run on stand untill the oil temp changes or shall I ride it? If ride in what rpm range shall I ride until what temps?

doesnt matter. i ride off after a 30second warm up, i just dont nuts until i hit atleast 150 ( gunning it at every light, wacking the throttle open for absolutely no reason other than to chuckle :p)

I have the same issue with the S2R 800, And as He Man said it is just the way the engine runs with the OEM Setup.
I recently had a full Termi system installed and I have noticed the engine is now much happier to run all the way down to 3000 RPM, also it's a good Idea to change your front sprocket to a 14 tooth, that will also help if, like in my situation you live in a suburb with lots of tiny little twists and turns (Lots of tiny round-a-bouts)

My specifications:
06 S2R 1000
Spark Mid pipe (CAT eliminator)
Arc Fabrication slash cut megs, straight thru but baffled (barely baffled)
O2 disconnected
Stock air box
14 T drive sprocket
stock rear sprocket
15K-ish miles

Mine does the same thing and at times it is fairly pronounced. I'd say it covers a range of about 700 or so RPM From mid to high 2000's to low to mid 3000.

I HATE it !

It is not really a problem when you are on a back road, a freeway or other road where you get up to spped quickly and carry a speed of 50 MPH or over. When it really annoys me is "around town" or 35 to 40 mph steady throttle.

Instead of "flat spot" to me it seems like the FI is doing quick, on-off, on-off, on-off (you get the idea) or it feels somewhat like chain snatch.

Very annoying and not confidence inspiring when doing slow speed manuvers, like a 90 degree turn off a main street onto a side street...Far worse when not fully warmed up.

My mechanic told me that it is programmed into the computer 'cause that is the RPM range that they run their emission test at to pass Govt regs. That explaination makes sense to me.


I don't know if we are talking about the same problem? I know I don't have the same problem as CairnsDuc as his 800 doesn't have the O2 sensor and the related problems. But, I wonder if my sysmtoms more accurately match the OP?

Also, right after my mechanic tuned the bike it was hardly noticable (12K) it has gotten worse since the tune up though, I hope it doesn't get progressively wosre up to the next service...3K away.

I wonder if the DP computer would cure my symptoms? I really don't want to spend $1300...only to find out it doesn't.

I love the bike but really hate that part of it and what annoys me more is that it doesn't have to be that way but for the tree huggin' greenies out there...Grrr. Take your bicycle, go hug a tree and leave my motorcycle alone!

Most Ducati's are not happy running below 3500 RPM, mine is the same, it'll do it, but it doesn't like it, keep it above 3500, preferable above 4000 rpm and it's a happy camper, I remember reading somewhere about the firing sequence of the Cylinders that cause the problem, something about the time between the 2 cylinders firing and then being ready to fire again causes the dramas below 4000 rpm.

My memory aint what it used to be 

I would suggest you need to lower your gearing, the Monsters are over geared to pass emissions testing, I changed to a 14 tooth front sprocket on the front and it's much happier.

well i totally disagree with everyone here , your flat spot is due too leaning out  , but you us of a lads bikes are much leaner than our Aussie    bikes if your duc dealer is any good they can richern her up , my pulls harder than a 14 year old boy from 2 k , but ive tricked the air temp censor in to thinking it cold , so that richened my bike evern  more , then once you reach 4 k the cpu just takes over and all the censor become redundant   

Ok... so if I rev in 1st 2nd I feel no flat spot, I guess because of the gearing, so a smaller sprocket should help in higher gears.
If I cruise with 3k (in all gears) there is no problem, the engine runs smooth.
But if I try to accelerate from 3k in gears above 3rd it struggles untill 4k.
I have also been told by a biker that each bike has a "flat spot" because of these emission standards...
I will save the money for the Termi and put it on next spring, I guess the air filter, ecu and bigger pipes should solve the lean issue.

Quote from: slick on October 01, 2008, 08:48:46 AM
Ok... so if I rev in 1st 2nd I feel no flat spot, I guess because of the gearing, so a smaller sprocket should help in higher gears.
If I cruise with 3k (in all gears) there is no problem, the engine runs smooth.
But if I try to accelerate from 3k in gears above 3rd it struggles untill 4k.
I have also been told by a biker that each bike has a "flat spot" because of these emission standards...
I will save the money for the Termi and put it on next spring, I guess the air filter, ecu and bigger pipes should solve the lean issue.

You're cruising around at 3K RPMs?

solution:

upshift

the bike doesn't have a flat spot

it isn't making any power at 3K

Quote from: Mother on October 01, 2008, 11:36:00 AM
solution:

upshift

the bike doesn't have a flat spot

it isn't making any power at 3K

I love posting redundently

<note to self...read thread before posting