CBR125 struggling to start

el_oso · World Chat Champion Joined: 17 May 2008 Karma :

recently purchased a CBR125 as a winter/commuter hack. I've had no real luck trying to get it started. The bike has been sat (apparently) for the the last 18months.

So far I've tried fresh fuel and checked the airbox and breather hoses for blockages all seem clear. I've taken the carb off and cleaned it, didn't seem to gummy anyway. I've had the spark plug out to check the spark and it's good and blue. It's strong enough to shock me through two pairs of gloves. The one thing I did think that was a bit odd was that the plug was bone dry. I would have thought that if fuel was going through and not igniting it should at least be slightly damp.

I've had it running a couple of times but would die instantly unless I have the throttle open at maybe halfway or more. Any ideas? Clean the carb again paying particular attention to the pilot circuit?
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Duke 390
Previous: '05 XR125L | '96 XJ600S Diversion |'05 Suzuki GSXR1000 | '05 Honda CBR125-R | '97 YZF 600R Thundercat | '11 Honda CBR250
Car: Jeep Wrangler 4.0L

UrbanRacer · World Chat Champion Joined: 26 Jul 2005 Karma :

Side stand sensor fault? Killswitch fault?

el_oso · World Chat Champion Joined: 17 May 2008 Karma :

P.addy · Red Rocket Joined: 14 Feb 2008 Karma :

Assuming 04-early 07 given the carb, they use a vacuum tap which is terrible. Make sure that it is working as intended. The rubber hose degrades and means no vacuum.

Also, the take breathers get caught VERY easily, sitting on the bike, right hand side, 2 rubber hoses should be under the tank, make sure its not kinked.

el_oso · World Chat Champion Joined: 17 May 2008 Karma :

yeah, I had a quick look at the tap and it didn't seem great. I removed the breather hoses after a while and still no luck. I'll have a look at the vacum hose tonight see if there are any leaks.
Fuel seems to be getting into the float bowl though. I undid the float bowl drain screw and that was full of fuel, just not sure anything is getting into the cylinder. Can't be sure though. I would expect the plug to be wet though.
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Duke 390
Previous: '05 XR125L | '96 XJ600S Diversion |'05 Suzuki GSXR1000 | '05 Honda CBR125-R | '97 YZF 600R Thundercat | '11 Honda CBR250
Car: Jeep Wrangler 4.0L

P.addy · Red Rocket Joined: 14 Feb 2008 Karma :

Only thing then would be jets, but assume you'd have cleaned them when you cleaned the carb?

el_oso · World Chat Champion Joined: 17 May 2008 Karma :

I would have thought so to. Might have been a little careless as it looked pretty clean anyway.
____________________
Duke 390
Previous: '05 XR125L | '96 XJ600S Diversion |'05 Suzuki GSXR1000 | '05 Honda CBR125-R | '97 YZF 600R Thundercat | '11 Honda CBR250
Car: Jeep Wrangler 4.0L