zx2r sluggish midrange acceleration, whats the go?

Alrighty I took the zx2r for a decent spin today and let her fly

Its fairly quick off the start and if you rev out first pretty high and snap into 2nd and continue the trend up the gears its like a bullet all the way!

But say if you let the revs drop in 2nd back down to about 3 or something for a tight corner then give it a lot of throttle, it picks up fairly quick but when it hits about 4.5-6 it feels really flat acceleration wise then about 6.5 and up WEEEEEEEEEEE bullet again. Even the sound it makes is like a flat spot uuuuuuuuuupflaaaaaatBIIIGUUUUUUUUUUUUP


Would there be anything causing this sluggish midrange acceleration is it just normal for 250s to be like that?

I've been told thats just how they are down low, so I guess thats it unless anyone else wants to say so

Jesus! You ride that thing around that sorta revs?

250s, you gotta rev em mate. On my old CBR250R I never let the revs drop below 6K for just round town riding etc, more often then not though, 8K. And when goin for a mountain blast or something, never below 10K.

In other words, all 250s have got stuff all power below 8K really.

Also, giving it wide open throttle below its powerband is likely "labouring" the engine.

Nothin ever made my 250 feel better though than a good carby clean.

Just get a 2 stroke..

But yeah, keep the revs up and she'll be right...

Heh ta guys, too used to driving my bogandore and the CB250 at Q-Ride that rev sfa.


I'll pick the revs up a bit then and see how I go

If you aren't flat spotting under normal acceleration off the line, then you are probably finding a bit between low/high fueling...not sure how it is achieved on your bike, but likely it is dumping fuel in that it can't burn because the revs aren't high enough. The fact that it clears its throat seems to suggest that, along with the fact you can take off smartly without incident.

I'm going with the audience, Ed. Keep the motor in the revs...

Dude it's a 250cc that red lines at 19K....

Here's the fix.. Don't let it rev down below 4K if you want it to have power.. I suggest 6-8 if you want to pull hard out of a corner.

As for the flat spot, well that'd prob be carbs.. prob one of the jets..

I had a problem with my ZX2R shuddering and not being able to rev past about 11-12K but i dunno what the problem was cause the carbs were swapped and it fixed the problem. *shrugs*

Been almost a year since i Had my ZX2 now, and my memory isn't that great.. Way to many fun memories of the ZX6 to erase my memories of my ZX2.. heheheh


Dan

I rode a CBR250 made and had to have em up around 7-8 to even get em moving. My gawd, it sucked. Give em heaps and she should be right. It shouldnt take you all that long to get used to it and when you will it will be a blast!

I remember when the Spewie RG250 was first released the Tacho STARTED at 4000rpm. Its a small bore 2 stroke mate Perfect to learn clutch control on. Give it biscuits n slide the clutch heaps. Max power will be just over 3/4 s to redline, make that your new home.
Cheers Brett

Hrm after a more thorough experimentation with a decent 3/4 hour ride today my mate reckons its most likely carby. Some more symptoms I found when taking it for a decent run today.

Sitting at 60 in third about 7 thou(which is in the troubled range) is chuggy, its not smooth it like stutters and jerks a fair bit holding constant speed.

It wouldn't start up the top of Mt Grav mountain, had to clutch it. Started fine everytime after that. Think that may have been the choke or something, after fiddling with the lever and turning it back off it fired up first go no probs and after a stop about another 10 mins later and 30 mins later.

Its got the chuggy flatspot through all the gears, it just isnt very noticeable in first after much experimentation its from about 5.5-8. Takes off once it hits 8 though in any gear.

It almost stalled out at the lights, it just choked and spluttered a bit when I went to go, had no power, had to clutch in rev it up a bit then take off again.


So how much is a carb clean/balance gonna set me back.. crap more expenditure I can't afford Anyone recommend a good place around Moorooka? Or southside even?


Gave my mates FZR a fair ride for comparison, its much much muuuuuch smoother from low revs than mine at the mo. Top end however the zx2r takes off

Ah much more information there Definately Fuel dramas imo. Tanya had the name of what sounded like a good 'canic down south side. None of the ones near you have impressed me but others may have had a better run n can reccomend someone.
As for the fzr. Potentially a 250 Two stroke = 500 fourstroke.
Hope you get it sorted, guys did these things have Power Valves or was that just the Yammies.
Cheers Brett

Im just hoping its nothing major cause I couldn't test ride the bike as I couldn't ride for shit at the time.

I just went by my mates judgement who could ride and he said it was a good buy.


Anyone fill me in on a rough estimate of a carb clean/balance?

clean and balance the carbies and get a new airfilter and it will go like the clappers.

How much is that gonna cost me (even if its a rough estimate), noone has told me yet!

I'm heaps poor now so I'm wondering how far I'm gonna have to dip into my savings I didn't wanna touch to get her running nicely.

Ok, just a guess here, but I think you should be able to get away with no more than $250, probably a lot less. I had some carby work done (stip down and clean etc) on my ER5 recently, and it only added $120 to the service - balancing carbs is quite easy, just you need a couple of vacuum guages.

Leave it to an expert, and they should be able to sort it out reasonably quickly, and without too much damage $$$$.