gasgasian Posted December 30, 2003 Report Share Posted December 30, 2003 Can anyone give me an idea about a knocking and pinking problem with my Gas Gas 300 04 model? I Quote Link to comment Share on other sites More sharing options...
outlaw dave Posted December 30, 2003 Report Share Posted December 30, 2003 GasGasian, Where are you located ? If in the UK contact Kevin at John Shirts - The Round Slide Del Orto has a FUEL screw - not an Air screw. - It sounds like you should put it back to stock then check to see if the pilot is plugged - If you don't have any luck, email me direct through Trials Central Aye Outlaw Dave Quote Link to comment Share on other sites More sharing options...
lineaway Posted December 30, 2003 Report Share Posted December 30, 2003 Before anything else try removing/replacing the vent overflow valve. The ball tends to stick. Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted December 31, 2003 Report Share Posted December 31, 2003 Which dealer did you buy it from Ian? Quote Link to comment Share on other sites More sharing options...
gasgasian Posted December 31, 2003 Author Report Share Posted December 31, 2003 It was bought used with 5 trials behind it. Quote Link to comment Share on other sites More sharing options...
physco Posted December 31, 2003 Report Share Posted December 31, 2003 HI, maybe 5 trials old but where did it come from?.contact gas gas uk and they will tell you which dealer it was from new?.i have just had a new machine from my dealer,!!!te brothers from dar!!!ton.no problems at all,handed over to my a! the spanner.buy your machines from a reputable dealer.with the dealer i deal with any problems i just ask,if they cannot sort it just speak to gas gas uk.the guy they have in their service department at gas gas uk is one of the nicest guys you will ever deal with,as long as its not an import!.i have loads of new bikes from the above dealer,betas,monts,gas,never had a problem with their service.and before you ask i am not sponsored by them,do not work for them,i have just built up a good relation ship with what i consider a realy good trials shop. Quote Link to comment Share on other sites More sharing options...
Andy Posted December 31, 2003 Report Share Posted December 31, 2003 Psycho - You can say White Brothers of Darlington if you want! I'm not adverse to the odd little plug if folk are happy with service. Quote Link to comment Share on other sites More sharing options...
jtt Posted December 31, 2003 Report Share Posted December 31, 2003 I'd also confirm the previous owner hadn't messed with the timing. I know it's not supposed to be adjustable, but that won't stop a moderately skilled mechanic. I'm assuming that since you tried 2 different carbs that the jets were clear on both and not blocked (but definitely worth checking as Dave said). You might try a richer pilot jet, can only help. Jetting specs are only a starting point and each bike will be slightly different, particularly on the pilot circuit, at least in my experience. I've never had much success with "recommened jetting"...perhaps it's this clean salt air The other obvious possibilities are fuel quality and compression. Try some fresh fuel, if you haven't already, and perhaps add some good octane boost to it or better yet, try some real race fuel. There are several thicknesses of base gasket available for most of the Pros, so again, the previous owner might have messed about with these and increased the compression to levels that will not run clean on pump gas. Quote Link to comment Share on other sites More sharing options...
ridgrunr Posted December 31, 2003 Report Share Posted December 31, 2003 I was looking through the GAS GAS maintenance video and Jim Snell mentions a possible knocking problem in the mid ranges under load if the carburator float level is set incorrectly. Mixture leans out too much as the bowl empties and the bike knocks. So, you might check the float levels. I think he said they should set 18.5mm, but you should check to see if that's correct before change them. Quote Link to comment Share on other sites More sharing options...
gasgasian Posted January 1, 2004 Author Report Share Posted January 1, 2004 (edited) I've tried going up slightly on pilot, 2 a 36, though about float height, but not to sure?? maybe?? not had a prob on any other gassers and not even a change when swapping carbs, they couldn't be both out surely?? Regard, confused.... PS if i do a flick turn or lift the front up in a slow vertical wheelie, when i drop it and accelerate i hear a pinking??????? DOH... Ian. Edited January 1, 2004 by gasgasian Quote Link to comment Share on other sites More sharing options...
jtt Posted January 1, 2004 Report Share Posted January 1, 2004 (edited) Best to check the float height and be sure. I have seen several Pros with float heights wrong from stock. I'd also go richer on the pilot. I run a 38 most times in my 280. Edited January 1, 2004 by JTT Quote Link to comment Share on other sites More sharing options...
clarkp Posted January 1, 2004 Report Share Posted January 1, 2004 I too think the pilot jet could be the problem - Billy Traynor discussed the same type of problem with me about my Beta - when you chop off the throttle after a wheelie or a hill climb (any throttle on action) the engine is still producing a large vacuum from the throttle-on, but the pilot circuit isn't rich enough to satisfy the condition thereby you get a momentary 'ping' until the vacuum dies back to a partial or low throttle condition. My pilot jet was 27.5 (Mikuni) and I went to a 40 to start and have backed down now to a 37.5. Quote Link to comment Share on other sites More sharing options...
gasgasian Posted January 1, 2004 Author Report Share Posted January 1, 2004 thanks 4 help, i think maybe i need 2 go to a 38?? pilot, i'll get 1 sent 4 ASAP. regards, Ian. Quote Link to comment Share on other sites More sharing options...
windlestone Posted January 1, 2004 Report Share Posted January 1, 2004 when i first rode my 02 250 pro if i wheelied then put down the front end the plastic front brake disc cover chattered like crazy. noise got faster/louder when revving. it could sound like pinking. just a thought coz i'm puzzled why you would have two carb's producing the same fault. Quote Link to comment Share on other sites More sharing options...
wayne thais Posted January 2, 2004 Report Share Posted January 2, 2004 Make sure that your fuel valve is not restricted. Try running the bike with the valve in the reserve position. I don't know if GG uses the same valve as Sherco but the stand pipe in the fuel valve was too long and had to be cut off. The bike would starve for fuel and knock in the normal run position but would run fine in reserve. Wayne Quote Link to comment Share on other sites More sharing options...
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