Carburetor issues CBR125RS6

Bezzaboy1234 · 30 Jun 2012 at 14:07

Hi peeps,

So I have been having problems with my carb for the past month now, And thought i'd share my woes with you guys and see if anyone could shed some light on my problem/questions,

So basically my bike was stuttering constantly, at first it wouldnt start but some fiddling of the idle screw and it was working, I was told by a few people it might be the spark plug, I took the old one out and it looked fine to me but I had a spare lying around so I chucked it in, no difference at all,

Took it to the garage and was told it was probably the carb, We stripped it and gave the carb a good clean, the only thing wrong was a screw at the bottom that was stuck in there, wouldn't come out no matter what, So I gave it to a guy I knew who could drill it out for me,

Feeling pretty glum about having to get chauffer driven everywhere I hopped on a well known auction site to see if I could find the screw or possibly a new carb, and managed to grab a new carb for £20,

Now my question(s) are,

1) Do you think I should use the new carb or the old one, the old one was cosmetically looking abit shabby, and this new one appears to be good.
2) What is this screw located in the pic for? this is the screw that would not come out, does anyone know what it actually does? I cannot seem to get it out of the new carb either along with some other stubborn screws :/

Thanks guys

Screw from old carb:

Picture of a random carb, not either of mine, just need to know what this screw does:

Bezzaboy1234 · 30 Jun 2012 at 15:01

Ah, Well thats the screw that simply will not budge, Wont move even a tiny bit, I've had enough trying to heat it up and get it out as it just won't move.

Wondering whether I should take it to my local garage and ask them to sort it out =/

Bezzaboy1234 · 30 Jun 2012 at 15:23

Don't have any of that, Will have to look around and see if I can get some,

Sonic bath? I Don't think I have access to one of those.

I don't really have anything that can apply Heat, I tried a small hand held chef blow torch thing but it has no gas,

I think I'll leave it for today as the head is starting to get worn and I don't want to completely lose it, May just end up asking the garage to do it as this is just more hassle than its worth. :/

Bezzaboy1234 · 30 Jun 2012 at 18:19

Aren't you supposed to be able to adjust the mixture screw? thats what was causing my bike to stutter..

Bezzaboy1234 · 14 Jul 2012 at 17:00

Ok, So quick update, Got the new screw, its the Air Filter screw. Put it in, re-assemble the bike, still the same problem, Tightened up about half way, then proceeded to tighten it, and loosen it, But nothing really changed,

Does anyone know what I can do? Really stuck on whats wrong

Bezzaboy1234 · 15 Jul 2012 at 21:15

famas said:
I'd check your fuel line filters to make sure there clean and not clogged up.

the screw you have taken out is the pilot screw, on most carbs there should be a rubber o-ring and washer after the spring as well, do you have a workshop manual to confirm this?

this link might help you set your pilot screw.
http://www.exriders.com/archive/topic/229923-1.html

Okay, I will try that next,

Yeah It does have a spring and a little washer and o-ring.

Thanks for that link, I will try that too

Bezzaboy1234 · 15 Jul 2012 at 21:16

wazza300 said:
have you been riding it in heavy rain? could be plug cap/lead shorting spray with wd40 inside and out

could try a hotter plug?

No not really, I tend to stay away from the rain, This started happening when it was fairly dry and sunny.

I don't even know what a plug cap/lead is,

Or a hotter plug? could you please explain

Bezzaboy1234 · 17 Jul 2012 at 17:18

atpbx said:
Unscrew the spark plug, take a picture of the end that was in the engine and post it on here.

I suspect we will see its burnt to buggery.

When this first started happening I took the spark plug out and it was dirty, Replaced it with a new one the day after.

Bezzaboy1234 · 17 Jul 2012 at 17:21

Quick update:

Everyone has been saying check the airfilter, and I did, It looks like a really dirty bit of cardboard, So I have ordered a replacement filter today, Hopefully that will fix it,

and to Timmy222,

Thanks, I was wondering which screw it was, I tried that and it has been abit more stable, but still juttery, hopefully it is just the air filter, I can pop it in, do some adjustments and hopefully i'll be back after almost a month of no riding

Fingers crossed

Bezzaboy1234 · 17 Jul 2012 at 22:00

.one. said:
You do not need to wait for the air filter to arrive just try it with out the filter it will run a little lean but you will notice if the stuttering has stopped or not.

Just with the air filter box, no filter? or can I leave the air filter box open?

Bezzaboy1234 · 19 Jul 2012 at 18:24

Ok so I left it and the filter came today, Fitted it, same problem =/ I honestly am now really puzzled as to what the problem is, I've checked all the hoses, Changed the spark plug, changed the air filter, new fuel, new oil, new coolant, I am at my wits end

Bezzaboy1234 · 19 Jul 2012 at 19:39

wazza300 said:
drained petrol tank of fuel just incase water has got in there? by a hotter plug i meant one grade higher than the spark plug you have installed, clean the spark plug cap and spray inside it with wd40 to drive out any damp/moisture ect

Did that originally, completely drained and re-fulled it, Still same problem, Currently I can't get the spark plug out, don't have a spanner that fits so i'll have to get one tommorow, might try looking at that again.

Bezzaboy1234 · 19 Jul 2012 at 19:45

sketchytom said:
since you have done the basics i think its electrical

coil lead and cap are what i would replace

after a quick google it seems a common problem. im sure if you do a google you should be able to get the specs for the resistance that the coil should give off and test with a multi meter. the specs will give you a range that the resistance should be in

Okay, How would I test the coil lead and cap? would I Simply put the multimeter tips up the cap?

Bezzaboy1234 · 19 Jul 2012 at 20:03

sketchytom said:
no electric shocks will happen lol
i just edited my above post have a look

oh and when you check your ht lead .... give it a wiggle whilst keeping an eye on the multi meter, what you are looking for is a break in the lead that could cause these issues due to it vibrating about

Ok, I am still unsure which end or what im supposed to be testing with the multimeter,

here's a picture of the CBR coil and cap, where am I supposed to be testing??

Bezzaboy1234 · 19 Jul 2012 at 20:37

Ok, Will do, gonna do it now

EDIT: I don't have a service manual, and cannot find the resistances im supposed to be looking out for online? anyone know where I Can find them?

Bezzaboy1234 · 19 Jul 2012 at 20:50

I've scoured everywhere and there aren't any specifics on my bike

Bezzaboy1234 · 19 Jul 2012 at 21:25

so here's my ignition coil thing:

If you are referring to the long cable going into the black coil thing, I can't unscrew it there is no way too, the other two ends are just screw holes that go into the frame which is the ground I assume? I can't see any way of testing it like this? also the multimeter I have doesn't work, Do you mean test the small cable?

Bezzaboy1234 · 19 Jul 2012 at 21:26

stiv121 said:
You might be able to download a basic manual for the bike somewhere rather that look at it on a webpage

Where? I've looked and can't find it ANYWHERE

Bezzaboy1234 · 20 Jul 2012 at 13:26

True =/, I need to know where to measure first, I can't see anyway to get the HT lead off the coil in order to test it. Maybe im better off letting a garage know and seeing if they can fix it.

Bezzaboy1234 · 24 Jul 2012 at 11:45

Got it back from the garage yesterday and its fine, The gap for the spark plug was too small, it had too much oil in, and the pilot screw needed some fine tuning and bam it runs just as it used to

,

Now I just need to look at the horn and the headlights as they don't appear to be working, Might have disconnected them at some point accidently