Loopyjasper Posted August 3, 2008 Share Posted August 3, 2008 I have an FZ1 2006 with only 2500 miles which will coughs and backfires when running. At first the engine would cough occasionally then be ok. This has got more and more frequent and now will hardly run at all and kangeroos along the road. The bike has had diagnostic run by a garage but apparently the result was that everything is ok. The bike runs ok at tickover and revs ok but as soon as the engine is under load, that is when the problem starts. I was wondering if it could be a problem with the air induction system. There are two rubber hoses from the rocker cover which connect to the "AIR CUT VALVE ASSY" (name taken from the yamaha microfiche) and another hose goes from there to, presumably, the airbox. Does this control the flow of air to the cylinders? There are two wires from this valve which go to a connector block under the headstock, these two wire were cut by mistake but reconnected with spade connectors. Could the cutting of these wires be creating the problem described above? Any help at all would be appreciated. Link to comment Share on other sites More sharing options...
yoda Posted August 3, 2008 Share Posted August 3, 2008 Does it do it in damp weather or will it do it in warm dry weather? Link to comment Share on other sites More sharing options...
Loopyjasper Posted August 3, 2008 Author Share Posted August 3, 2008 Does it do it in damp weather or will it do it in warm dry weather? Does it all the time unfortunately, I am living in Tenerife so almost everyday is warm and dry. Link to comment Share on other sites More sharing options...
yoda Posted August 3, 2008 Share Posted August 3, 2008 I was just checking that it wasn't an icing problem. Well my best guess is that you have a faulty spark plug or plug lead. Check that the plug leads are not damaged in any way and that they are all secure to the plugs. Find out if all the cylinders are firing by checking the exhaust header temperatures, straight after it starts to happen. Check your airbox for leaves or dead mice etc and that the throttle bodies are OK. I suspect that the bike warms up and then this starts to happen so probably not a fuel problem but check that the fuel line is not getting too hot and vapourising the fuel. Come back here when you have tried all of that. Just a thought, is the sidestand switch secure? Any kill swithes that are intermitant will also cause this problem Link to comment Share on other sites More sharing options...
Loopyjasper Posted August 4, 2008 Author Share Posted August 4, 2008 Yoda - many thanks for your suggestions, the sidestand switch connector block located under the petrol tank seems to be at fault. The connector must have been disconnected by the previous owner and in doing so, the clip to keep it tightly fastened together has been broken. Therefore the connection has been making and breaking. The connector has been cleaned up and cable tied together and all seems well again. Mucho, mucho gracias. Link to comment Share on other sites More sharing options...
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