Guest Posted March 28, 2015 Share Posted March 28, 2015 Hi all,Wanted to pick your brains if I could on an issue I'm having with a newly bought 06 CBR 125.The bike starts usually with a bit of choke or throttle, but will eventually stall at steady revs or when at idle. The bike has a big bore dyne jetted carb and a custom exhaust.Things I've tried:Checking fuel pump/hoseCleaned pilot jet and float bowlReplaced ignition coilReplaced choke cableCleaned air boxChanged engine oilChanged spark plugChecked for blockages/uncleanliness in tubingChecked for any kinked hoses.Tried different idle screw adjustmentsFirst bike, just want to get it up and running, any advice most welcome!Cheers Quote Link to comment Share on other sites More sharing options...
Tango Posted March 28, 2015 Share Posted March 28, 2015 Welcome to TMBF mate........ When you say you checked the fuel pump, how? I'm not sure, but I seem to recall that I've seen on here that the fuel pump on the older CBR and CBF 125's were subject to a replacement recall....... Quote Link to comment Share on other sites More sharing options...
Guest Posted March 28, 2015 Share Posted March 28, 2015 Thanks mate I'm definitely still a rookie, so bear with me if I get any names wrong. I'm sure it's not fuel flow that's an issue - the vacuum for the tank works as I've tested for it, and the carb definitely receives fuel as it can be drained. Quote Link to comment Share on other sites More sharing options...
Tango Posted March 28, 2015 Share Posted March 28, 2015 It sounds like fuel starvation.......is the fuel tank breather ok? Plenty of fuel in the tank? It's not got a load of water in the tank? Fuel filter ok? Petrol tap ok? Quote Link to comment Share on other sites More sharing options...
Guest Posted March 28, 2015 Share Posted March 28, 2015 Tank breather seems fine, no hissing when petrol cap is taken off after it stalls. Suction to the vacuum hose pulls through the petrol, and carb float bowl will always drain off fuel when I try.Cleaned out most of the carb, including taking off float bowl and chamber, main and pilot jets and reassembling. Now the bike won't start at all. Booked in to see a mechanic but rather cut the two week wait and cost if I can get it running myself.... such an odd issue Quote Link to comment Share on other sites More sharing options...
Lumor_uk Posted March 28, 2015 Share Posted March 28, 2015 Welcome to TMBF mate........ When you say you checked the fuel pump, how? I'm not sure, but I seem to recall that I've seen on here that the fuel pump on the older CBR and CBF 125's were subject to a replacement recall....... is fuel pump exclusive to injected bikes? I remember having a mechanical fuel pump on 1 litre 1986 fiesta. Quote Link to comment Share on other sites More sharing options...
DreamytimeEscorts Posted March 29, 2015 Share Posted March 29, 2015 Hi all,The bike has a big bore dyne jetted carb and a custom exhaust.Cheers There's your problem. Quote Link to comment Share on other sites More sharing options...
Guest Posted April 2, 2015 Share Posted April 2, 2015 So I've replaced the custom carb back to a working stock carb, but it still won't start. Fuel seems to be going through to the carb ok. Air filter is clean. Spark plug has been changed, though with it not starting the plug is coming with a very small amount of wet oil on the end. Could this be a sign of flooding?I've charged the battery and tried starting it with and without choke and throttle, no luck. Pulled out the plug and turned it over to see if that released anything in the engine, still no luck. Quote Link to comment Share on other sites More sharing options...
Lumor_uk Posted April 2, 2015 Share Posted April 2, 2015 shouldn't be oil should be fuel on the plug if it's not igniting. oil would mean the piston rings are shot and you've got no compression. Quote Link to comment Share on other sites More sharing options...
Guest Posted April 2, 2015 Share Posted April 2, 2015 Ok, so hands up, I made a stupid mistake. When I changed out the carb I connected the float bowl overflow tube to the tank. Nothing drained out of the overflow once this has been properly reset. I'm pretty sure I'm dealing with a flooded engine. I've tried taking out the plugs and starting it to evaporate the gases, but no success yet. Plugs are coming out wet with oil after a few cranks. Leaving spark plug out overnight and charging battery, see what j get. Engine doesn't sound close to starting, though fuel is being delivered to the carb, battery and ignition all sound good. Quote Link to comment Share on other sites More sharing options...
DreamytimeEscorts Posted April 3, 2015 Share Posted April 3, 2015 Do you have a spark? Take the plug out and connect it back to the HT lead and rest the plug on the top of the head to earth it and try starting it. If you get no spark, you'll probably need a new coil but check your HT lead first with a continuity tester. Your plug will be wet because of unburnt fuel. Quote Link to comment Share on other sites More sharing options...
Guest Posted April 3, 2015 Share Posted April 3, 2015 Thanks for the tip. It seems I've lost spark. I had another plug and ignition coil, replaced both but still no spark, which would explain why it won't start and the unburnt fuel. One issue seems to lead to another! Not sure if there's much else I can do with what I've got, so I'll just have to wait until it gets to the Honda dealer next Friday Cheers for your help everyone Quote Link to comment Share on other sites More sharing options...
Tango Posted April 3, 2015 Share Posted April 3, 2015 Maybe the CDI unit is dead.......also check the air gap on the pulse sender.....and the wiring from the sender to the CDI unit..... Quote Link to comment Share on other sites More sharing options...
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