sy250 Posted May 23, 2005 Report Share Posted May 23, 2005 (edited) I took my Scorpa out at the weekend and it run lovely. Brought it home, cleaned air filter and filled it up with petrol. It started and run for about 20 seconds and then stopped. Kicked it a few times and it backfired (very loud). Cleaned carb and cleaned plug and put it back together but with no joy. Has anyone got any ideas. Edited May 25, 2005 by sy250 Quote Link to comment Share on other sites More sharing options...
james111089 Posted May 23, 2005 Report Share Posted May 23, 2005 try a new plug it might not be sparking under compression. James Quote Link to comment Share on other sites More sharing options...
jools Posted May 23, 2005 Report Share Posted May 23, 2005 Has you 'woodruff' key gone? that causes back firing badly if that goes! Quote Link to comment Share on other sites More sharing options...
sy250 Posted May 23, 2005 Author Report Share Posted May 23, 2005 Thanks for all the advice. Quote Link to comment Share on other sites More sharing options...
boofont Posted May 24, 2005 Report Share Posted May 24, 2005 Has it just started doing it? Mine does it quite a lot but it was worse untill I retarded the ignition. It'll backfire after a kick then start. Quote Link to comment Share on other sites More sharing options...
sy250 Posted May 24, 2005 Author Report Share Posted May 24, 2005 It has always backfired but not this often. Waiting for the plugs to arrive. If they do not work i think it could be the woodruff key. But what i can't understand is that it run lovely for 3 hours on Sunday????? Started first kick and never backfired. Quote Link to comment Share on other sites More sharing options...
steveo Posted May 24, 2005 Report Share Posted May 24, 2005 The back firing is very much a part of the SY Racing which are the only 250 Scorpas imported into Australia.On my 2004 SY I retarded the timimg back to the Original timing mark settings and had no back firing at all.On the 2002 and 2003 SY Racing the back firing caused the Expansion chamber to split slightly,which then needed to be rewelded.I have found if you over oil your Air Cleaner foam it will enhance the problem.Have now 4 air cleaner elements and replace after a days ride,save the used ones till they all need cleaning..clean them all together and continue the cycle.Let us know how you go when you fit the new plug.Will be very surprised if the woodruff key has come adrift. Quote Link to comment Share on other sites More sharing options...
lastplacebrad Posted May 24, 2005 Report Share Posted May 24, 2005 Glad this came up as a topic , thought it was just my bike that did this ,though it starts fine still !, apart from sometimes it seems a little reluctant to start from cold , the symptoms being , if you dont catch it well enough to start on first kick, it then needs the fuel turning off and full throttle ....wrong pilot jet ? too much oil on filter? ...... BTW starts absolutely perfect once warm Cheers Brad . Quote Link to comment Share on other sites More sharing options...
robee Posted May 24, 2005 Report Share Posted May 24, 2005 Mine does it also once in a while. Ever since I turned the timing up a bit. Interesting yours just began doing it out of the blue. Quote Link to comment Share on other sites More sharing options...
sy250 Posted May 24, 2005 Author Report Share Posted May 24, 2005 It has always backfired but never this often. It is only done it about 3 times in 8 months then about 3 times in 5 minutes Quote Link to comment Share on other sites More sharing options...
shercool Posted May 25, 2005 Report Share Posted May 25, 2005 I had 2 Scorpa's, a 2001 and a 2004, and they both backfired every now and again, people used to really s*** themselves when it happened in a queue !! Quote Link to comment Share on other sites More sharing options...
markscorpa Posted May 25, 2005 Report Share Posted May 25, 2005 i ve had an 03 and now got an 04 sy250 03 backfired every now and again when i used the kill switch 04 does it very rarely i had a word with crosswaites and they said nothing to worry about but check the carb could be a bit of water there ? Quote Link to comment Share on other sites More sharing options...
ossagripper250 Posted May 25, 2005 Report Share Posted May 25, 2005 sounds like the timing to me.a mate had a fantic that sheared a woodruff key and that backfired once, ran for a few seconds and refused to start again.due to the fact the woodruff key is important to the timing it would explain why the bike will not run anymore. just a thought, see if it hepls Quote Link to comment Share on other sites More sharing options...
sy250 Posted May 25, 2005 Author Report Share Posted May 25, 2005 All fixed. NGK platinum spark plug arrived today from Birkett. Started first kick and run lovely. Very happy. Quote Link to comment Share on other sites More sharing options...
james111089 Posted May 25, 2005 Report Share Posted May 25, 2005 glad to hear you fixed it James Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.