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Discussion Starter · #1 ·
So basically, when im riding, my bike goes great above say 6000rpm, but if im going around 60kmh, and in gear 4 or 5 (around 4000rpm) and just slightly moving throttle (1/4 inch - 1/2 inch) it makes a put put sound. (literally like "put put put put put put put [accelerate more] brrrrrr - normal again)

If i open up the throttle, sound goes away. I've cleaned my carbs, changed plugs, etc. my thoughts are:

Fuel - i'm currently running a tank of Vortex 98 and alternate between unleaded and that. im wondering if Vortex 98 is a benefit in my engine or i should just run regular?:huh:

RPM range - what is the optimum rpm range i should keep the bike in, when just normal traveling, because i barely ever reach 14,000rpm unless gunning it, let alone 18,000, and usually use 5th gear at 50-60kmh which is maybe 4000rpm max.

Jet blocked - i hear that depending on the amount of throttle you apply, different jets take over in the carb. if i only apply a little bit of throttle, would a blocked jet cause this put put sound.
 

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It's been a while since I had a 250, but I'm pretty sure it works best at revs above 8000. Anything less than 4k and you be working the motor pretty hard.
A lot of people say reg unleaded is the best option for the bike. 98 unleaded apparently gums up the carbs
 

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The cbr250 engine makes peak torque (read: extracts the most energy from the fuel or "bang for your buck") at somewhere around 10,500rpm, peak power comes in at about 15,000rpm. Between these two engine speeds is your powerband (a pink one I believe), basically if you're in a hurry away from the lights or getting up to speed, this is where you want the bike to be.
When cruising along I like to keep the cibbie spinning at 8,000-11,000rpm so opening the throttle results in actual acceleration and closing it gives some engine braking.
When passing through a town I'll leave her about 3rd so as to keep the noise down ( <6,000rpm) or until some cager makes me stop. 5th gear is too high imo.

I dunno about the petrol being a problem, here we have the options of 98RON petrol and diesel:p, no fancy "regular" unleaded. Though we could throw in some 2T mix to make life interesting:D
 

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I dont think I ever rode mine like that as the yoshi can was too loud all the time. Bit like the GPZ - harldy gets over 5k
 

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joshtammi said:
RPM range - what is the optimum rpm range i should keep the bike in, when just normal traveling, because i barely ever reach 14,000rpm unless gunning it, let alone 18,000, and usually use 5th gear at 50-60kmh which is maybe 4000rpm max.
This is far too low of an RPM to be in while cruising.
Ideally, as others have said, is to at least be 8K or above, whatever speed your doing.

Don't worry, I found it hard to adjust as my car's cruising RPM is just under 3K.. now I have to listen to CBR revving @ 8K. :(
 

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Discussion Starter · #14 ·
yeaah, thats my problem. i live in canberra, and riding to school on 8000rpm? i look like a total wanker:p

my friends always turn their heads and think im gunning it at about 110 in a 40 zone, when in reality im going 30.

but i guess i'll give it a go. Thanks for all the help guys
 

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joshtammi said:
yeaah, thats my problem. i live in canberra, and riding to school on 8000rpm? i look like a total wanker:p

my friends always turn their heads and think im gunning it at about 110 in a 40 zone, when in reality im going 30.
Give yer mates a bit of perspective, demonstrate what 18k sounds like and scoff at the 6-8k redline their cages are stuck with:p.

And don't worry bout the rest of canberra, the advantage of wearing a helmet is no one can see you laughing at their indignation (you can also sing aloud to yourself without any embarrassment).

You'll quickly get used to what the bike is happy doing and adjust your riding style to suit. Before you know it, you'll be redlining the engine before you cross an intersection after the lights change:D
 

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Yogi said:
joshtammi said:
yeaah, thats my problem. i live in canberra, and riding to school on 8000rpm? i look like a total wanker:p

my friends always turn their heads and think im gunning it at about 110 in a 40 zone, when in reality im going 30.
Give yer mates a bit of perspective, demonstrate what 18k sounds like and scoff at the 6-8k redline their cages are stuck with:p.

And don't worry bout the rest of canberra, the advantage of wearing a helmet is no one can see you laughing at their indignation (you can also sing aloud to yourself without any embarrassment).

You'll quickly get used to what the bike is happy doing and adjust your riding style to suit. Before you know it, you'll be redlining the engine before you cross an intersection after the lights change:D
Summed up perfectly, and there is nothing wrong with turning heads. i used to love doing it as i left college.

come down past the front of school at 8000-10,000 RPM, everyone looks thinking you're about to hit redline, then crack it open to 18,000 RPM and watch the jaws drop. ride away with epic grin.

this applies to every other public place as well, except maybe out the front of a cop shop.
 
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