2002 tuono starting probs

[john boy]

hi i am doing some work on a 2002 tuono with starting probs,customer only just picked up bike & said it started up 3 times fine when he picked it up,got it home and only started once then started playing up,had to put new starter sprag in as was on way out,check & ajusted valve clearance & timing still did not start well,i had a guess that valves was not seating well as front bypass hole was making more noise than normal so did a leak down test & there was a 18% leak on front & only normal ish 6 to 7% on rear,to back this up squirted a bit of brake cleaner down into inlet track & there was allot of bubbles! none on rear.so thought taking off head & seating valves would fix starting probs as inlet presure sensor would get strange reading from front valves not closeing propperly & pushing air back up(i have had this before).but the problem is still there,if you spray a mist of brake cleaner over tb's it fires up ticks over & revs up fine but soon as you tern off & try starting on the button it will not fire unless you spray a mist over tb's again,i have checked loads,set tps checked reading from cam & intake pressure sensor seem fine has a spark fuel pump primes & got compression no EFI fault code just comes up with no start on dash.i checked injectors by supplying 12v with propper test equipment & if you tern ignition on to prime fuel system then open tb's & fire the injector with 12v it squirts a healthy jet of fuel out,but if you connect injectors back up to loom & open tb's to se if any fuel comes out when you hit start button there is nothing squirting out but soon as you spray a mist of brake cleaner it fires up then runs fine,not very many bikes make me think this hard so thought i would try for some guidence on here to se if some1 has come across this before,it just seems the injectors are not firering on cranking but fire fine after you give it a hand with a squirt of easy start(mist of brake cleaner)whitch points towards lack of compression but have sorted the leaking valves out thanks for any help in advance

[THUNDR]

Did you read this thread? May give you more ideas? Pg 3

http://www.apriliaforum.com/forums/s...quits-suddenly

[john boy]

hi guys,sorted the problem out in the end,it was the ecu,i think the customer may of spiked the ecu when useing a jump pack fitted another secound hand ecu it fired stright up,i think it must of bin getting confused on the start up faze in the memory as like i said when you squirt easy start down inlet it started and ran fine,it hasn't taken this long to fix i just been busy as i am starting up my own workshop & will be doing all aprilia serviceing so if your down near dorset drop me an e,mail at jbmotorcycleservices@hotmail.co.uk .also be doing all other makes of serviceing suzuki,yam,kawasaki etc

[BrummyMax]

Good luck to you! Independent people that are conscientious are like gold.