How do I safely strip cbr125 to clean carb?

Gaz-t1esto · Borekit Bruiser Joined: 24 Apr 2008 Karma :

Having a few fueling problems and through trial and error I have come to conclusion that the carb is where the fault lies.

Problem is that when i open throttle, the bike isnt getting the right air/fuel mixture and its just dieing. it dies when I ride it too if i dont open throttle past so many revs. as a temp repair to get me home from work i increased the idle revs (little knob under carb that i turned a few times to satisfy my curiosity to see what it did). this did help however was only a temp job and now the bike isnt starting or when it does start it sometimes idles too high. tried turning the revs back down but the knob under the carb doesnt seem to be affecting the revs now.

To cut a long story short, i know it needs a good clean or replaced and wonder how is the best and safest way to remove the tank without fuel going everywhere and/or is there a tap on the bottom of the tank so i dont need to transfer fuel into a storage can. also, what tools will i require to clean the carb. obviously wouldnt be wise to use wire brush but is there certain spirits/spray cleaners i should or shouldnt use.

Thanks

Gaz

[edit - typos]

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

First off:

Carburettor cleaner from Halfords is your friend.

Secondly, following Robby's advice from a previous thread I would strongly reccomend NOT dismantling or fiddling with the carburettor before you have definately ruled out ignition or electrical problems. Carburettors have a habit of never quite being the same if you remove and/or dismantle them. Plus As Robby quite rightly says Carbs simply do not go wrong unless they are very very old or have really really contaminated petrol put through them. Particularly on such a new bike as a CBR125, you should not be seeing fuelling issues. Do a compression check, test the spark from the spark plugs and try to reset the carbs to factory defaults.

If you still have issues, by all means dismantle the carb but be aware you're opening a huge can o' worms by doing that.

Karma

____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

Gaz-t1esto · Borekit Bruiser Joined: 24 Apr 2008 Karma :

Finglonga · World Chat Champion Joined: 27 Jul 2004 Karma :

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Could be a few things instead of the carb.

However if you have been fiddling with a screw in the underside of the carb then that is likely the idle mixture screw. It has a small effect on idle speed but mainly adjusting it is likely to have really screwed up the mixture. It will have next to no effect on the mixture when you are riding at any speed.

Personal guess would be that the problem is a blocked fuel filter, blocked fuel tank breather or a kinked fuel line. Any of these will starve the carb of fuel.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

Gaz-t1esto · Borekit Bruiser Joined: 24 Apr 2008 Karma :

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

He means that if if was a carb problem it would slow just about as much as if you turned the ignition switch off.

If it is stopping violently then that suggests it is just nipping up (ie, lightly seizing). Which is FAR more serious than a carb issue (and pretty rare on a 4 stroke).

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

Gaz-t1esto · Borekit Bruiser Joined: 24 Apr 2008 Karma :

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

Gaz-t1esto · Borekit Bruiser Joined: 24 Apr 2008 Karma :

oil levels are fine. with preheat, its just below max, without preheating engine its roughly about the middle of the dipstick.

ms51ves3 · Super Spammer Joined: 07 Jun 2007 Karma :

Gaz-t1esto · Borekit Bruiser Joined: 24 Apr 2008 Karma :

Gaz-t1esto · Borekit Bruiser Joined: 24 Apr 2008 Karma :

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

Gaz-t1esto · Borekit Bruiser Joined: 24 Apr 2008 Karma :

stirlinggaz · World Chat Champion Joined: 22 Jul 2007 Karma :

hi,
if your certain your gonna strip the carb :
remove seats,
remove tank bolt (12 or 14mm socket iirc)
lft tank up & pull off the 2 hoses-but label them 1st!
ones vacuum & ones fuel.
pull the tank off, watching for those massive breathers that go down through the plastic bit next to carb.
fuel wont spill out as you need vacuum for the fuel to flow.
remove choke assembly (spanner 12 mm i think) from carb.
loosen throttle cable on the side of carb.
loosen the jubilee clip & pull the carb off, remembering where the hoses go.
theres not much can go wrong with they carbs, unless, as has been mentioned before, someone has been messing with the brass
mixture screw or the idle screw.(the one facing downwards,knurled edge)
cheers,
GAZ