chorleytrialsclub Posted February 15, 2010 Report Share Posted February 15, 2010 Hello, Could anyone offer any advice on my bike please. my bikes pinking a little, have had carb (delltoroto) off and cleaned out with compressed air, small jet seems very small, my sherco i could see clear light through, this one seems to be harder to 'see' through although was passing air freely through both holes, not adjusted mixture screw yet, It only tends to do it when revving harder. changed plug, also it does not start as good as i like my bikes to start, is this common with the 300, certainly needs a leg full usually, my 280 gg was a really good starter that had the iridium plug, are they better? thinking of going for the keihn carb i have heard they make a big difference. Quote Link to comment Share on other sites More sharing options...
tricky dicky Posted February 15, 2010 Report Share Posted February 15, 2010 Have a look what size the pilot jet is. It should have a number in the 30's on it. It ideally wants to be either a 33, 34 or 35. If its not right when its being revved hard it sounds like the main jet though. The mixture screw should be between 3.5 and 4.5 turns out on a dellorto. That should make the diffrence to how it picks up rather than how it revs out though. The keihin carbs are good but an expensive fix for probably a small problem. Hope this helps. Quote Link to comment Share on other sites More sharing options...
chorleytrialsclub Posted February 15, 2010 Author Report Share Posted February 15, 2010 Thanks for that dicky the mixture screw was nearly fully out, think i counted six 5 or 6 turns it has a 35 needle and 118 main jet, not tried it running yet but seeing as the mixture screw was so far out i am hoping it will solve the problem, will try it out tuesday, wasn't running that bad just noticed a a little pinking at higher revs Thanks again.. J Quote Link to comment Share on other sites More sharing options...
gasgas68 Posted February 16, 2010 Report Share Posted February 16, 2010 I had a similar problem with my 300, tried everything and it turned out to be a leaking base gasket. Just another option! Quote Link to comment Share on other sites More sharing options...
chorleytrialsclub Posted February 21, 2010 Author Report Share Posted February 21, 2010 Thanks for advice, I hope it dont need a base gasket... Still not right, adjusted air screw as advised, moved needle up and down, looks like on the body of the carb the pilot jet hole is not aligned right through, other deltorto carbs i have messed with you can see right through eaisly when you take the pilot out, mine looks like the hole is 'offset' like its been drilled from either side and hole does not line up spot on. i have had a nozzle cleaner through it smallest size and fetteled it a bit and it has made hole slot on the inside of carb body, but not fully cleared it out, this has made it better to see through the hole but i am considering drilling it through, if i can, could anyone advise if this will be ok to do and what size should i use, will need to be about .5mm - 1mm drill i think. Dont like this pinking thing it grates me when i ride it.. Quote Link to comment Share on other sites More sharing options...
wri5hty Posted February 22, 2010 Report Share Posted February 22, 2010 Not sure about your pinking problem. but do know 300s are a bitch to start, i have to give mine a big leg full and have cracked 3 clutch covers across the kick start shaft hole. try to have the kick start at the top of its stroke rather than just whollop down on it. there is a art to starting a 300 and I'm no artist. Quote Link to comment Share on other sites More sharing options...
tricky dicky Posted February 22, 2010 Report Share Posted February 22, 2010 This may be a long shot but did you check the size of the pilot jet? I reckon on a 300 it probably wants a 35 pilot in. Another more rare occurance that is possible is that the reed block rubber could have a hole in the sidewall and that will make it run really weak. Quote Link to comment Share on other sites More sharing options...
chorleytrialsclub Posted February 22, 2010 Author Report Share Posted February 22, 2010 Yes dicky the pilot is a 35, I think the trouble could be with the hole that the pilot screws into, Just looks wrong, slighty offset, thanks for your help, has anyone ever had to drill the carb pilot jet hole? i will continue with my quest to sort it, ye it is a bit of a legfull to start it, my older 280 was a great starter, put it down to an iridum plug, Strange when you get rid of one bike that is seven years older and have all these problems with a newer one!! i want my 280 back...it was a sweet one...and 2grand less...happy dayz Quote Link to comment Share on other sites More sharing options...
jse Posted February 22, 2010 Report Share Posted February 22, 2010 Yes dicky the pilot is a 35, I think the trouble could be with the hole that the pilot screws into, Just looks wrong, slighty offset, thanks for your help, has anyone ever had to drill the carb pilot jet hole? i will continue with my quest to sort it, ye it is a bit of a legfull to start it, my older 280 was a great starter, put it down to an iridum plug, Strange when you get rid of one bike that is seven years older and have all these problems with a newer one!! i want my 280 back...it was a sweet one...and 2grand less...happy dayz The #35 can be a little lean on some engines (I run a #38 in my 280), but the #118 main (and needle in the D36 range) should be fine. The pilot jet usually does not affect the A/F mixture above 1/8th throttle in general. I think you mentioned the pinking at higher throttle settings so I might also suspect an air leak (rare in an 09'), possibly in the manifold/reedcage area (usually caused by overtightening). A leakdown test would reveal an air leak, but most riders (and a lot of shops) do not have the equipment. A restricted exhaust can also cause these symptoms, but the bike seems too new to have developed carbon buildup at the front of the headpipe. In my experience, an NGK BPR5EIX set at .024" is one of the best plugs for the GasGas TXT and Pro TXT models (and especially when starting the 05' 300). jon Quote Link to comment Share on other sites More sharing options...
tricky dicky Posted February 23, 2010 Report Share Posted February 23, 2010 If its pinking at higher revs that suggests its on the main jet. It wants 122 in to run right but it should really come with that in if its UK supplied. It could well be just the needle. Quote Link to comment Share on other sites More sharing options...
chorleytrialsclub Posted February 23, 2010 Author Report Share Posted February 23, 2010 Many thanks for your advice. Intresting dicky you said 122 main jet, Mine has 118 main jet gotta be a uk bike, i have moved the needle up and down seems best in third position from top, i will ring gaser for a 122 main and try a 38 pilot as Mr JSE mentioned, my other gaser had the NGK BPR5EIX and it was a sweet starter and run really crisp, just hope to get it sorted before weekend!!! J Quote Link to comment Share on other sites More sharing options...
tricky dicky Posted February 23, 2010 Report Share Posted February 23, 2010 I reckon it will run far too rich with a 38 pilot in. Remember the climate in the UK is far different to the USA. I would only go up as far as a 35 pilot and try the 122 main. That will make the top end a bit better. Quote Link to comment Share on other sites More sharing options...
bikespace Posted February 23, 2010 Report Share Posted February 23, 2010 Well after all the techy talk I feel a bit insignificant asking about fuel, but are you using high octane stuff or just standard unleaded? I was surprised how much of a difference it made to mine. Really does pink sometimes on regular unleaded. Just a thought. Quote Link to comment Share on other sites More sharing options...
jse Posted February 23, 2010 Report Share Posted February 23, 2010 Well after all the techy talk I feel a bit insignificant asking about fuel, but are you using high octane stuff or just standard unleaded?I was surprised how much of a difference it made to mine. Really does pink sometimes on regular unleaded. Just a thought. Very good point. Whereas, the older GG bikes called for 95 octane, the newer ones can tolerate 91/92 octane, provided the jetting is set correctly, but I would not run them on regular. The cost savings is not worth the possibility of engine damage. Jon Quote Link to comment Share on other sites More sharing options...
copemech Posted February 24, 2010 Report Share Posted February 24, 2010 Very good point. Whereas, the older GG bikes called for 95 octane, the newer ones can tolerate 91/92 octane, provided the jetting isset correctly, but I would not run them on regular. The cost savings is not worth the possibility of engine damage. Jon Jon, you gotta remember these guys speak RON, not R+M/2 method ! Yet still, i think their premium gas is comperable at 98 RON to our 91/92 best i can tell. Seems most are getting the 10% ethanol treat to go along! What crap! Quote Link to comment Share on other sites More sharing options...
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