January 8, 200818 yr Can anyone help i have two 290 Sherco both our 07 one is a standard bike and the other is a Cabestany. The standard bike is very hard to start and when you rev it it pinks and the same with the Cabestany but it starts ok. the carb and air filters our clean. i think it is a carb or petrol problem can anyone tell me what the following would be for both bike the standard bike has a Dellorto and the Cabestany has a Keihin What is the right pertol oil mix what size of pilot what position of needle how many turns on air screw what spark plug do yo need to change the reeds from standard and if anyone else has any other ideas on making the two bike run smoothly
January 9, 200818 yr On the dellorto, 36 pilot 118-120 main 3rd groove down needle Ck o-ring on brass tube(see other post) No immediate need to change reeds, I like the Boyesens, smoother off the bottom 2-3 turns out on the screw, adj as ness. Try a BP5EVX gapped at .027, bit easier starting anl better low rev performance for both bikes, or you can go with the irridium, but I would keep the gap back to .025 as it is a resistor plug. 80:1 full synthetic Maxima K2 works for the US guys, your mileage may vary. I ran the Kiehin briefly on the '07, but went back. They are powerfun, yet can be finicky! 45/125 on the jets seems a good start, others may differ JJH needle in mid groove 2-3 turns on the screw They may all be a pig to start when the temps are down. One old trick is to tip the bike fully over on its left side to the ground. This (hopefully) spills a bit of fuel into the carb helping to prime things. Hope that helps!
January 9, 200818 yr Might be a coincidence but I've notice my 07 290 (standard model Dellorto carb) pinking in third and fourth gear recently as well. It never used to do it so it's either temperature related or the fuel I'm using. I clean the carb and air filter before every event using an airline to clean jets drillings etc so the carb is always clean. Always buy 98 ron super unleaded from Tesco's petrol station nearby but I'm thinking of travelling 5 miles to the nearest Shell garage and reverting back to Shell Optimax and trying that instead. I'm out this weekend so I will see how it goes.
January 9, 200818 yr carbon build up on the head and piston crown will cause this in some cases. due to the cold weather all two strokes run leaner. the engine runs hotter and the combination causes pre-ignition which is the ping you can hear. i have in the past always altered my carb settings/jetting for summer and winter. once you have experimented with jetting you get a feel for where to go, its quite hard to put down in words, but as a rule jet up and make richer in winter and down in summer. this site has a good explaination of pre ignition. hope this helps. paul. http://www.ngkntk.co.uk/working/RunScript....\Pg176.asp
January 11, 200818 yr Sorry, I just seen this, but my math suggests 5000cc of petrol / 80 cc= 62.5 cc of oil per 5 L!
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