08 Ninja 250 lost power

[Dave1]

Hello,

I bought a 250 Ninja about a month ago, and everything has been great until I was accelerating out of a roundabout yesterday and about half way through the rev range, she lost power (quite a lot, maybe to 30% of usual). I pulled over, she was idling fine and responded just like normal to a quick light rev, but when taking off again didn't have nearly as much grunt as usual. When I eventually got her home, I noticed a small amount of oil dripping down the fairing which I initially thought may have been coming from the engine, but I had recently oiled the chain and it appears that may be the source.

Now I don't know too much about bikes, but it seems like it could be a carby problem? I'm keen to get into the mechanical side of things, but don't have much experience/equipment. The bike is only 500km from the 12,000km service, so another option is to take it in for an early service and get the pros to sort it out.

Does anyone know if this sounds like the sort of problem that I should be having a go at? If so, where would I start?

Thanks in advance,

Dave

[tigertim20]

you said it responds normally to giving it a rev?
take it for a ride up the road, start by idling along, then whack the throttle wide open, and watch the gauges.
see if the rpm goes up as quickly as normal to redline, but the bike fails to accelerate smoothly, and as quickly as it used to.
If this happens, you clutch is slipping. if this is the case, the cluch itself will set you back $100, plus fitting, so not a major.
this page has a list of parts available for your bike off the shelf, they guy delivers within a day or two, very good service, have used several time
http://www.bits4bikes.co.nz/parts/kawasaki/2093.aspx

I doubt its the carbs, that would happen slowly over time, a clutch on the other hand can occaisionally let go at almost random.
it is low kays, but being a learner bike, its entirely possible that either you, or a previous owner has raped the clutch a bit.

as for doing it yourself, errrm. probably one you should let the shop do, or someone you know who is mechanically minded, and watch them and get them to explain as they go.

If you want to get into the mechanical side of things, start off by buying a fucked motor off trademe for $50, get a manual, and start doing minor jobs on it, like removing the head, and cams, then resetting the timing etc, or removing and reokacing the clutch, that way you can practice the processess as many times as you like without the risk of damaging your valuable bike.

keep us updated.

[p.dath]

I'd go for the early service.

[Dave1]

Thanks tigertim,

Pretty sure it's not the clutch. It responds to a light and quick rev like normal (not much throttle), but when opened up there isn't much there. The revs don't go anywhere.

My carb thoughts were (please correct me if wrong - likely) that the idler jet could be fine - hence the low throttle response being normal, and maybe a clogged main jet - explaining the lack of power when I ask for more? Wouldn't it be possible that something flowed into it and blocked it up relatively instantly?

[tigertim20]

Thanks tigertim,

Pretty sure it's not the clutch. It responds to a light and quick rev like normal (not much throttle), but when opened up there isn't much there. The revs don't go anywhere.

My carb thoughts were (please correct me if wrong - likely) that the idler jet could be fine - hence the low throttle response being normal, and maybe a clogged main jet - explaining the lack of power when I ask for more? Wouldn't it be possible that something flowed into it and blocked it up relatively instantly?

I will explain how carbs work..
you have fuel, and you have air.
black magic happens.
motorbike goes forwards.

Follow Pdaths advice, go for the early service

[Dave1]

Here's an update for anyone interested:

Took my bike in for an early service today. The problem was that the carb's main jet was blocked, but now she's all fixed. I'm gonna look at getting a cheap old thing to tinker around with and do some learning.

[tigertim20]

Here's an update for anyone interested:

Took my bike in for an early service today. The problem was that the carb's main jet was blocked, but now she's all fixed. I'm gonna look at getting a cheap old thing to tinker around with and do some learning.

great idea, youll learn heaps, be sure to get a manual for it as well

[White trash]

Here's an update for anyone interested:

Took my bike in for an early service today. The problem was that the carb's main jet was blocked, but now she's all fixed. I'm gonna look at getting a cheap old thing to tinker around with and do some learning.

Awesome! I love it when the newbie with "little motorbike knowledge" hit's the nail on the head when he theorises what could cause a symptom.

TigTim, where the hell did the clutch theory come from bro? :D