cwill83247 Posted February 23, 2014 Report Share Posted February 23, 2014 Hi I have a 2003 gas gas pro runs like a dream and sounds good when on choke.. But then when choke is off makes like a knock noise when low revs or if blip throttle quickly.l Is this what's known as pinking .. Any help or advice would be appreciated .. Quote Link to comment Share on other sites More sharing options...
tltel Posted February 23, 2014 Report Share Posted February 23, 2014 This sounds like a lean fuel knock, Give the carb a clean and check fuel flow. If carb has a filter clean that too. It will sometimes knock like this as you run out of fuel or its time to turn tap to reserve. TLTEL Quote Link to comment Share on other sites More sharing options...
lee99780 Posted February 23, 2014 Report Share Posted February 23, 2014 I experienced similar problems on my 06 300. Checked all the obvious. All OK. Ran it totally empty, cleaned everything out and changed my fuel/oil mixture slightly. Job done! Quote Link to comment Share on other sites More sharing options...
tltel Posted February 23, 2014 Report Share Posted February 23, 2014 Pinking will occur when engine is under load, TLTEL Quote Link to comment Share on other sites More sharing options...
rainey88 Posted February 27, 2014 Report Share Posted February 27, 2014 What year bike is it? Im having trouble with mine pinking more than i like.....eg even riding down the road. Which iv tried moving the position of the needle, which i believe is down to running to lean. Next step change the jets apparently. Its a keihin btw. Quote Link to comment Share on other sites More sharing options...
cwill83247 Posted March 7, 2014 Author Report Share Posted March 7, 2014 Rainey apologies for the delay unfortunately still can't figure it out.. On choke it's fine I will let you know if get to bottom of it.. Quote Link to comment Share on other sites More sharing options...
rainey88 Posted April 1, 2014 Report Share Posted April 1, 2014 How you getting on will? Iv ticked off alot of things to try including jets cant seem to change anything though. Quote Link to comment Share on other sites More sharing options...
cwill83247 Posted April 1, 2014 Author Report Share Posted April 1, 2014 I changed jets didn't make much difference .. My next 2 things are to decoke head from what I have read is your plug sooty .? And to set the squish.. Quote Link to comment Share on other sites More sharing options...
cwill83247 Posted April 1, 2014 Author Report Share Posted April 1, 2014 I changed jets didn't make much difference .. My next 2 things are to decoke head from what I have read is your plug sooty .? And to set the squish.. Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted April 2, 2014 Report Share Posted April 2, 2014 Pinking is what happens when you leave the red plastic parts in the sun too long and they fade to pink. Seriously, pinking (or pinging for us USA folks) is technically called pre-ignition. This happens when the incoming fuel charge ignites early, even before the spark plug fires. This can happen for several reasons: Timing set too far before top dead center, Too lean of a mixture A hot spot in the combustion chamber that lights the incoming fuel charge. Too low fuel octane for the actual engine compression. Because it runs well on choke, and not well off choke, I suspect the pilot jet is plugged or the mixture screw is not adjusted right. The idle circuit affect mixture throughout the rpm range, but more at idle and low RPMS. The main jets and needle only affect the bike at mid to high RPM. Moving the needle down (clip to higher groove) will make the mixture even more lean. Keihin carbs use an air screw to adjust rich/lean at idle. Turn in to reduce the air (more rich) turn out to increase the air (more lean). Squish is set by adjusting thickness of the base gaskets. This is done when rebuilding the engine and does not change over time. If you want to reduce compression, you can add a thicker gasket but this involves removing the head and jug. Decoking the head will reduce compression but more importantly, allow smooth swirl of the fuel charge in and out of the cylinder. Lean running bikes, rarely develop much coke buildup. Some people confuse light piston slap with pinking. This is not a fuel problem, it is a wear problem. Don't go crazy throwing parts at the bike or adjusting things at random. That may fix the symptom but not the root cause of the problem. Get a knowledgeable buddy to listen to the bike and do some real troubleshooting. 1 Quote Link to comment Share on other sites More sharing options...
cactusjack Posted April 2, 2014 Report Share Posted April 2, 2014 Good answer thats_a_five. You are also correct in that it is pinging, not pinking! Never heard it called pinking until I got onto this forum. Quote Link to comment Share on other sites More sharing options...
tltel Posted April 2, 2014 Report Share Posted April 2, 2014 I think its always been pinking in this country. I remember my dad demonstrating pinking in his Morris minor in the early 70's. I had never heard of pinging till I came on this Forum. TLTEL Quote Link to comment Share on other sites More sharing options...
cactusjack Posted April 4, 2014 Report Share Posted April 4, 2014 It's funny how there is such different versions of our language every where you go. So interesting. I remember being in Canada in 2006 and they used to get stuck into us Aussies for saying 'I reckon ........' It is so commonly used here you don't blink an eyelid, but there, we got laughed at. Quote Link to comment Share on other sites More sharing options...
cwill83247 Posted April 7, 2014 Author Report Share Posted April 7, 2014 Well followed the advice given and went back to basics Removed head and it was coked up cleaned up the head and piston New plug . Drained fuel Replaced with super unleaded No more pinking (pinging for our American friends) Happy days.. I will keep you posted as haven't gone for a ride but ran it until nice and warm fan kicked in and no horrible noise when blip throttle.. Hope this helps someone else thanks all.. Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted April 7, 2014 Report Share Posted April 7, 2014 Great that you got it fixed. "Good on ya" as they say in some part of the world. Quote Link to comment Share on other sites More sharing options...
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