CBR250 Forums banner
1 - 13 of 13 Posts

·
Registered
Joined
·
15 Posts
Discussion Starter · #1 ·
Hey guys, just done a bit of service on my little beast (plugs, fuel filter, cleaned carbs). Problem is i struggled to find a definitive mixture screw setting and most of the guides and threads seemed to contradict one another. I ended up going 2 and half turns out. Now, the bike ran a whole lot better with a strong idle and good higher rev performance after the service. But its been a few days now and it appears to be developing (to me) and bit of pinging noise on backdown and a bit of stutter during me ringing its neck. Now if i go to gas it off at the lights i get a stutter that feels like both my sprockets are missing a few teeth. Im am assuming its running lean and my mechanic reckons I should go half a turn out to see if that helps. My question is; have i started even close to right setting? my bike is basically stock accept im running a foam air filter and the dyno guys stuck a big half inch drill down my stock exhaust can when i got it dyno tuned years ago. As far as i know the jets and needles are stock.

Thank you in advance for your help
smokinjoe
 

·
Registered
Joined
·
962 Posts
2 and a half turns out is too rich, it will run ok for a while but eventually you'll foul the spark plugs, I think 1 5/8 turns out is the stock setting.

Do you have an '88 or '89 MC19?
 

·
Registered
Joined
·
2,329 Posts
The pilot screws should be turned out to 1 5/8 revolutions for a stock bike according to the manual
So start from there and if its running lean, then slightly turn them out
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #5 ·
The bike is an 89, not sure if its a misfire, wouldnt it do it constantly if ii had a problem with the leads or coils?

Will reset to 1 and 5/8 and see how i go

cheers
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #6 ·
Just reset to correct mixture, hasn't changed at all, starting to think you might be right about the misfire, My number 3 lead is a bit shit house. Is it possible to pull the leads off the coils and just replace them?

cheers guys
 

·
Registered
Joined
·
962 Posts
smokinjo said:
Just reset to correct mixture, hasn't changed at all, starting to think you might be right about the misfire, My number 3 lead is a bit shit house. Is it possible to pull the leads off the coils and just replace them?

cheers guys
Yeah they have a plastic nut on the coil, just unscrew it and you can pull the lead off. You've gotta take tank and I think the airbox off too, to get to it.
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #8 ·
Yeah got em apart, they unscrew off the coils, only question is where to get some new ones. Turned up zero so far looking online.

Cheers
Smokinjo
 

·
Registered
Joined
·
962 Posts
I'd be looking at wreckers for ignition leads some wreckers can order parts new, or Honda dealers may be able to get them in.

I usually find what I need through www.findapart.com.au
I'm assuming you're in Australia.
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #10 ·
Okay guys, an update.

Sourced some leads, they are not new but are in far better condition then the rubbish i had. NO DIFFERENCE, starts and idle's strong, still getting a bit of pinging noise on back down at low revs (pulling up to the lights - zero throttle). When accelerating gets to around 8-10 RPM and it starts to stutter. This has me fucked because after i cleaned out the carbs replaced the fuel filter the bike was perfect. Wasn't until i replaced the plugs i started getting this shit happen. Got the plugs and carbs out now. Gonna inspect tmorrow (in daylight) for anything obvious. Gonna make sure the jets are stock too.

thanks in advance guys for any suggestions..
smokinjo
 

·
Registered
Joined
·
21 Posts
As the ignition is electric one Ma assume it to be the coil pick up, coil itself or ignition module. I'm in Australia and if you type in 1989 Honda mc19 Cbr 250 r' on eBay I believe the come up and aren't too expensive
 
1 - 13 of 13 Posts
Top