chapsta Posted January 3, 2015 Share Posted January 3, 2015 Hi there i have a 2010 fuel injecton model ybr. Last month it cut out on my commute to work . I was low on fuel and it was raining so done all the basics new plug new fuel checked wires etc nothing still so i look at the piston and it was chewed up and cracked. so ordered the 150 piston and cylinder kit fitted no problems went to start still wont start on button or bump start . I pulled off the fuel pipe at bottom to check fuel and it shot out with presure like theres a block somwhere in manifold but got no carb . Any help or ideals as i need this for work monday . Thanks adam Link to comment Share on other sites More sharing options...
blackhat250 Posted January 3, 2015 Share Posted January 3, 2015 Ok " so why was the piston chewed up. usually lack of oil, the fuel is pressurised by electric pump on injection systems, so that's normal, Link to comment Share on other sites More sharing options...
chapsta Posted January 6, 2015 Author Share Posted January 6, 2015 When i checked oil there was a bit in there . When i bought bike got told piston was changed as bike had a compleate rebuild . Ether way the bike ran 4000 miles to it quit on me thats when i checked piston . . The weekend i put some oil down the plug to aide conpresion and checked the fuel pipe still nothing and tried to bump again in 2nd and 3rd there is a bit of a screeching noise when trying to bump not sure if this the starter motor . Battrey bit flat so will charge weekend and try bit off easy start . Link to comment Share on other sites More sharing options...
chapsta Posted January 6, 2015 Author Share Posted January 6, 2015 When i checked oil there was a bit in there . When i bought bike got told piston was changed as bike had a compleate rebuild . Ether way the bike ran 4000 miles to it quit on me thats when i checked piston . . The weekend i put some oil down the plug to aide conpresion and checked the fuel pipe still nothing and tried to bump again in 2nd and 3rd there is a bit of a screeching noise when trying to bump not sure if this the starter motor . Battrey bit flat so will charge weekend and try bit off easy start . Link to comment Share on other sites More sharing options...
chapsta Posted January 9, 2015 Author Share Posted January 9, 2015 Could i have messed up with the timing chain thats what noise is . I made sure when bolted back up i was on the line in the timing gear the chain and cog turned few times round tho when bolting up but the mark nerver moved off the line in the crank case . Also should i have done anything to the valves after the rebuild because i nerver touched them . Would any of this stop it from starting Link to comment Share on other sites More sharing options...
blackhat250 Posted January 9, 2015 Share Posted January 9, 2015 Aye chapsta, when rebuilding a 4 stroke usually you test the head [ valve seatings] by turn head up. and pour fuel into the head, to see if it leaks by the valves, when you had the head off , you shouda ground the valves ,= better compression , You need a compression test now,,,this will reveal all. Anyway, you did 4000 miles,,did you check the oil level in this time,? Link to comment Share on other sites More sharing options...
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