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Discussion Starter #1
Hi guys, I am new on here. Have had my CBR250RR for few weeks now. I have similar story to most other guys who have encountered starting problems with their CBR250RRs. Anyway, as the story goes, bike used to start fine then one day did not start at all.
It cranks, but does not continue follow over.

Pulled apart petrol tank, petrol seems to drip away smoothly, don't think its battery, tried to push start no luck still and jump start with car battery, no luck either, pulled out my spark plugs, they looked rather dirty and smelt of petrol, wiped them clean and put them back in, still no start.
Whenever I try starting it, the exhaust backfires. I know I have flooded the engine with petrol.
What else can I do or check? Do you guys think it's the spark plugs or anything else?
I am a noob with bikes and don't know much so any suggestion will help.

This morning it finally started.. left it running for 10 mins then turned it off. Came back after 30mins and would not start again. I don't knw wat is wrong.

Thanks and have a good weekend.
 

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Discussion Starter #4
Thanks for the reply guys. Hrrm I decided to change the spark plugs as it's what was recommended from other CBR forums. The Carb seals were replaced and valve clearances done by the last owner, so I didn't think the Carbs was the problem.

The MC22 starts perfectly fine now! When I first took out the OLD spark plugs, it was black at the very end. It smelt and contained of petrol. I think with the little knowledge that I know about MC22s, that the spark plugs weren't getting any spark because of the petrol flooding it.

Now, that the NEW spark plugs are in, it starts first time every time.

MY ADVICE TO ANYONE WHO HAS A CBR250RR & HAS TROUBLE STARTING IT:
If it cranks, but doesn't follow through, Check your spark plugs first as this is cheap to replace and you've got to do it one day. Only thing you stress about is TIME. Taking off the fairings, the plastic covers on each side of the undertank, and loosening the radiator can take you up to 1 hour, but in my opinion, once you've done so, you have a better knowledge on where the bolts and screws sit for next time & a better understanding of your bike and its' parts.

This is my 2 cents!!
 

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Discussion Starter #5
Just came back from a 15 mins ride. Starting the bike is not a problem.
I got another problem now. The bike feels like it's misfiring. The bike just struggles to pull and the exhaust sounds weird. I have already changed all 4 spark plugs.. What could this be?

In addition, it only misfires on lower revs, b/w 0-8k rpm. Above 8k rpms it sounds fine.
 

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Discussion Starter #6
You know what guys, after putting in those fresh plugs, tried starting the bike this morning... NO F'ING LUCK AGAIN!!!!! It just cranks but doesn't follow through. Same story as last time before I changed the plugs.. I am over these Carb bikessss honestly... just CBF anymore..

Is there possibly anything else I can try ....
 

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You're not leaving the choke on for long after starting are you? It should only be used to actually get the bike running from cold, and once its caught you can moderate revs with the throttle and by riding gently until warm.

It may help if you explain in detail the procedure you use to start the bike. As an example, I turn the bikes ignition on, set kill switch to 'run', apply the choke and then hit the starter. Often I will give a few throttle twists just before I hit the starter with the throttle closed. Once running, I push choke back in and ride gently until temp comes up to the normal zone. Warm starts are similar, but with no choke and the throttle maybe 1/4 open. The idle when warm (10 min riding) is 1,500rpm.

I would also advise you check your air filter as a dirty filter will cause the bike to run rich and foul its plugs. This, in turn, will cause hard starting.

Cheers - boingk
 

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Discussion Starter #8
I am not even using choke at all boingk.

My method of turning on the bike is as follows:
Turn ignition on
Set switch to RUN
keep the fuel as ON
and press the starter button, never needed to use the accelerator in the past.

It does not follow through at all.
 

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Discussion Starter #9
u knw wat guys.. turns out .. the spark plugs I recently put in got fouled .. bought new ones..

Instead of buying NGK - CR9EH-9 ... I decided to buy CR8EH-9 the shop guy sed high heat resistance .. and now the bike starts and runs like normal again !!!!!
 

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xcwizit said:
Just came back from a 15 mins ride. Starting the bike is not a problem.
I got another problem now. The bike feels like it's misfiring. The bike just struggles to pull and the exhaust sounds weird. I have already changed all 4 spark plugs.. What could this be?

In addition, it only misfires on lower revs, b/w 0-8k rpm. Above 8k rpms it sounds fine.
My bike also did this after changing the plugs:(

does yours still do this??
 
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