View Full Version : Instant revs!
kunoichi
24th March 2009, 14:34
Hey guys,
I'v recently noticed that my kwaka ninja 250 2008 doesn't seem to gimme instant revs below 8000rpm. Is anybody else having this trouble? And anybody got hints as to wot to do with it? Ta
Big Zappa
24th March 2009, 17:24
slack throttle cable?
dirty carbs/fuel injectors?
dirty plugs?
Mully
24th March 2009, 17:39
Isn't it only a parallel twin?? I'm not sure they're big on revving their rings out.
CookMySock
24th March 2009, 18:03
Isn't it only a parallel twin?? I'm not sure they're big on revving their rings out.Yes its a parallel twin. They are quite revvy in comparison to the vtwins I hear. I havent ridden one, and I'm not familiar with this fault.
Steve
Reido
24th March 2009, 19:18
wonna describe this problem a bit more?
Slyer
24th March 2009, 20:23
You mean there's a fair delay between twisting the throttle and getting a response?
What about in neutral?
discotex
24th March 2009, 21:26
Can you post a vid of what you mean or if it only happens when riding maybe explain it a bit more clearly??
Am I the only one doing this? :scratch:
I'm keen for some instant revs if you guys figure out how to get them.
Gubb
24th March 2009, 21:49
Direct Exhaust Injection (DEI) is the only way to go.
motorbyclist
25th March 2009, 00:49
how instant is instant? is it bogging down? has it magically gotten slower over the weekend?
kunoichi
25th March 2009, 10:09
No it's been like this from the begining, and i thought it might of just been me needing to break the engine it. I have clocked over 7500Km now and after all the ATNR's, coro loop and northland loop, i consider my engine broken into. However this problem has not improved. Yes there is a delay between me twisting the throttle and getting a reaction, but only up until 8000rpm. Wen i'm sitting above 8000rpm she definatly gives me instant reaction and a great acceleration speed. I have no idea if this is normal or not, so i thought i'd ask.
I'll see if i can steal my sis's digital camera off her and record a vid for u guys this weekend. Cheers
Slyer
25th March 2009, 10:22
Ninja 250's have all their power up high in the RPM range, the low-mid is quite bad. You will find this is common of all of them.
This might be worse than usual however.
Ragingrob
25th March 2009, 10:25
Most bikes will not have instant acceleration when low down in the revs, especially the 250s.
Squiggles
25th March 2009, 10:35
I'll see if i can steal my sis's digital camera off her and record a vid for u guys this weekend. Cheers
Bring it to the chiller
kunoichi
25th March 2009, 10:42
Ninja 250's have all their power up high in the RPM range, the low-mid is quite bad. You will find this is common of all of them.
This might be worse than usual however.
Oh, i was just comparing my revs with that of my bf's bike, but yet again he's modified his bike. If its a normal thing, then mayb i'm just worrying about nothing<_<
CookMySock
25th March 2009, 10:44
I have clocked over 7500Km now and after all the ATNR's, coro loop and northland loop, i consider my engine broken into.I think its you who is getting broken in, miss! I think you are getting used to it. :cry:
I spose you are stuck with a 250 for some months are ya? Bugger!
Steve
Ragingrob
25th March 2009, 10:44
Oh, i was just comparing my revs with that of my bf's bike, but yet again he's modified his bike. If its a normal thing, then mayb i'm just worrying about nothing<_<
Lol and what kind of bike is that? If it's anything like a hornet it'll rev like crazy with the tickle of a feather!
Supermac Jr
25th March 2009, 10:46
Want to catch-up sometime to compare 'notes'?
kunoichi
25th March 2009, 10:48
u mite be right. I definitaly don't get the same kick out of it like i used too, still enjoyable, but it's mild now. I'm used to pillioning on 1000s and 600s. Speaking of which, i am over due for my restricted...
kunoichi
25th March 2009, 10:50
Rob: BF rides a hyosung gt 250, but he's been modifying it so it actually does have greater acceleration than my bike...which sux considering i used to be a challenge for him wen we first started riding together.
Supermac: sure i don't mind. Just PM me and we'll find a time and place
Slyer
25th March 2009, 11:00
Oh, i was just comparing my revs with that of my bf's bike, but yet again he's modified his bike. If its a normal thing, then mayb i'm just worrying about nothing<_<
His bike is a V Twin, the modifications won't have much to do with it.
V Twins are naturally more grunty in the mid range than your Parallel(inline) twin IIRC.
Inline engines are at their best at high revs. :)
kunoichi
25th March 2009, 11:02
LOL, it sounds like i need a crash coarse in motorbike mechanics. I don't know the difference between different engines except that they feel different! OH wot do u know! I'm a girl after all! :p
Morcs
25th March 2009, 11:04
Instant throttle response is only had with FI.
With carbs theres always a lag of sort.
motorbyclist
25th March 2009, 13:34
I have clocked over 7500Km now and after all the ATNR's, coro loop and northland loop, i consider my engine broken into. However this problem has not improved. Yes there is a delay between me twisting the throttle and getting a reaction, but only up until 8000rpm. Wen i'm sitting above 8000rpm she definatly gives me instant reaction and a great acceleration speed. I have no idea if this is normal or not, so i thought i'd ask.
firstly, this sounds like a fairly aggressive break in regime
secondly, what you describe sounds normal
Rob: BF rides a hyosung gt 250, but he's been modifying it so it actually does have greater acceleration than my bike...which sux considering i used to be a challenge for him wen we first started riding together.
oh I realise you you are now!
i'd hardly call that hyo modified, and your gpx ninja is more of a "monster" that his hyosung
CookMySock
25th March 2009, 14:11
Rob: BF rides a hyosung gt 250, but he's been modifying it so it actually does have greater acceleration than my bike...which sux considering i used to be a challenge for him wen we first started riding together. Haha, so learn how to corner better than him, and pass him on the outside.. LOL :devil2:
Steve
Tank
25th March 2009, 14:15
Haha, so learn how to corner better than him, and pass him on the outside.. LOL :devil2:
Steve
The guy rides a Hobag 250. You need to get past him a.s.a.p so you dont get hit with all the bits that fall off it as he's riding.
bastardsquad
27th March 2009, 09:09
His bike is a V Twin, the modifications won't have much to do with it.
V Twins are naturally more grunty in the mid range than your Parallel(inline) twin IIRC.
Inline engines are at their best at high revs. :)
You got it in one with your first post , and i'll agree with you here also. I'm riding the 07 GPX250 and its much the same, fairly unremarkable and unresponsive below about 7000 RPM...however 7000-13000 redline is a very different story.Dont be afraid to rev it and ride in the higher RPM range !:woohoo:
xwhatsit
27th March 2009, 09:52
His bike is a V Twin, the modifications won't have much to do with it.
V Twins are naturally more grunty in the mid range than your Parallel(inline) twin IIRC.
Inline engines are at their best at high revs. :)
<img src="http://sleekupload.com/uploads_jpg/20/facepalm_4.jpg" />
Slyer
27th March 2009, 10:30
Facepalm
What was the point in that?
xwhatsit
27th March 2009, 12:20
What was the point in that?
Because the same silly nonsense keeps getting repeated over and over again. A V-twin and an inline twin are the same motor. The engineers can give them whatever characteristics they like -- even if you take a `traditional' V-twin where each piston shares the same crankpin, you can easily produce a parallel twin with the same firing interval by constructing a crank with the pins spaced at 45 degrees, or 90 degrees, or whatever you like. Take Yamaha's TRX850, a parallel twin, which has the same firing pattern (and hence the same sound and `feel', which is what they wanted for marketing purposes -- see the trellis frame etc.) as a 90-degree Ducati.
Parallel twins are produced in all kinds of different patterns. Brit twins were traditionally 360 degrees (i.e. both pistons rising and falling at once) and Jap twins were traditionally 270 degrees. But an engineer can dial in whatever he likes. And all it changes is the spacing of each firing pulse; aside from balance reasons affecting vibration limits, it has a fairly tenuous impact on torque or horsepower.
The reason for a GT250R being slow-revving and `torquey' compared to a GPX250/Ninja 250R or a GSX250 has much more to do with valve timing, combustion chamber design (including compression ratio), bore/stroke relationship, and any number of other variables that the designers tweaked to make it behave how it does.
The Pastor
27th March 2009, 12:26
Because the same silly nonsense keeps getting repeated over and over again. A V-twin and an inline twin are the same motor. The engineers can give them whatever characteristics they like -- even if you take a `traditional' V-twin where each piston shares the same crankpin, you can easily produce a parallel twin with the same firing interval by constructing a crank with the pins spaced at 45 degrees, or 90 degrees, or whatever you like. Take Yamaha's TRX850, a parallel twin, which has the same firing pattern (and hence the same sound and `feel', which is what they wanted for marketing purposes -- see the trellis frame etc.) as a 90-degree Ducati.
Parallel twins are produced in all kinds of different patterns. Brit twins were traditionally 360 degrees (i.e. both pistons rising and falling at once) and Jap twins were traditionally 270 degrees. But an engineer can dial in whatever he likes. And all it changes is the spacing of each firing pulse; aside from balance reasons affecting vibration limits, it has a fairly tenuous impact on torque or horsepower.
The reason for a GT250R being slow-revving and `torquey' compared to a GPX250/Ninja 250R or a GSX250 has much more to do with valve timing, combustion chamber design (including compression ratio), bore/stroke relationship, and any number of other variables that the designers tweaked to make it behave how it does.
mate you didnt have to go an educate him did ya?
xwhatsit
27th March 2009, 12:30
mate you didnt have to go an educate him did ya?
I'm not the smartest Asian guy, so I thought I knew what to say.
Slyer
27th March 2009, 12:37
Heresy! Burn him!
Maki
27th March 2009, 13:14
Hey guys,
I'v recently noticed that my kwaka ninja 250 2008 doesn't seem to gimme instant revs below 8000rpm. Is anybody else having this trouble? And anybody got hints as to wot to do with it? Ta
The solution to your problem is simple. Get the 2009 "big bang" Yamaha R1.
Howsie
27th March 2009, 21:56
You are correct, the Ninja is a bit gutless under 8000rpm.... then again it is a 250. Maybe cos your bf is beating you thats why you have only really noticed now. If you want to push the bike always ride above 8500rpm and give it heaps.
BTW 4th gear tops out at 110kmph at 13000rpm to give you a mark to go by.
The bike is happiest in the higher rev range, it can do it so use it!
Your engine was broken in after 20kms, then finished at about the 1000km mark so go nuts!
motorbyclist
28th March 2009, 11:12
A V-twin and an inline twin are the same motor.
likewise the new R1 is essentially a Vfour (that doesn't vibrate as much, with slightly less material/complexity in the top end and a more complicated crankshaft)
how/why it took them this long is beyond me - probably something to do with the honda being (alledgedly) better without any of the variable intake tracts etc etc so they thought they'd pull out an old project they'd been keeping for some time to release as a marketing ploy; "crosswank technology" or something like that... either that or they've only just figured out how to do it without snapping the crank.....
kinda like how food/drink companies come out with NEW chocolate/banana/strawberry/bananaberry flavour!!!11!! not exactly a breakthrough but they'd like you to think it is, and it's nice nonetheless
Blackshear
28th March 2009, 14:51
image.jpeg
behold
science
Cheshire Cat
10th May 2009, 13:26
LOL, it sounds like i need a crash coarse in motorbike mechanics. I don't know the difference between different engines except that they feel different! OH wot do u know! I'm a girl after all! :p
Hey, girls can do anything guys can :p
gatch
10th May 2009, 14:00
Rob: BF rides a hyosung gt 250, but he's been modifying it so it actually does have greater acceleration than my bike...
You should ask him when hes going to replace the drive shaft with a carbon fibre one, best thing you can do for a hyosung I hear..
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