Guest yamahadt50R Posted April 29, 2010 Share Posted April 29, 2010 Hi Everyone, I have a 1997 DT125R it used to be running absolutly fine before I bought it. I bought it off mate and put everything back together and now it wont rev past 9k which makes it go slow. I have taken pipe off looked up the barrel and turned the powervalve so it is completly open and pinned it there, it has a full dep system on it aswell i just cant get my head round that it wont rev past 9k revs. And suggestions are welcome, Many Thanks, Paul Link to comment Share on other sites More sharing options...
Moderator Airhead Posted April 29, 2010 Moderator Share Posted April 29, 2010 Hi Everyone, I have a 1997 DT125R it used to be running absolutly fine before I bought it. I bought it off mate and put everything back together and now it wont rev past 9k which makes it go slow. I have taken pipe off looked up the barrel and turned the powervalve so it is completly open and pinned it there, it has a full dep system on it aswell i just cant get my head round that it wont rev past 9k revs. And suggestions are welcome, Many Thanks, Paul Hi Everyone, I have a 1997 DT125R it used to be running absolutly fine before I bought it. How do you know? maybe it ran to 9000 when your mate had it. I bought it off mate and put everything back together and now it wont rev past 9k which makes it go slow. I thought it was running fine before you bought it! but it was in bits Already confused by what you are not telling us. Can you 'come clean' ...Paul Link to comment Share on other sites More sharing options...
Guest yamahadt50R Posted April 29, 2010 Share Posted April 29, 2010 Well i dont normaly need to state the obvious, when he had it up and running it was reving to 11k he sed then its was stripped to individual bits but it had no pannels on now exhaust system on and stuff like that i put it all back on the engine was still together so i havent touched it. Many Thanks, Paul Link to comment Share on other sites More sharing options...
satelliteone Posted April 30, 2010 Share Posted April 30, 2010 thats two peeps l8tly with he same problem..why did ya pin the pv open?..curious 9k!..mmmmm..did u do a top end rebuild, checked compression std is 110PSI on a new engine! , check spark plug gap, changed the plug even!..mines revs to 11k and the power band comes in at 6K... The zorst decoked?.. all boost bottles on. air filter cleaned.. gearbox oil at the right level.. right oil in there too, not like 20W50 engine oil.. grrr.. does it drink fuel? badly. tip for ya.. DTR`s eat plugs! dont ask, i dont know why, still working that 1 out! got a feeling its the shit coils! I use NGK BR9ES, only got to look at it, and it fails!..lol so many questions! Link to comment Share on other sites More sharing options...
Guest yamahadt50R Posted April 30, 2010 Share Posted April 30, 2010 Chhers for reply its had a top end rebuild and compression is ok not brilliant compared to my mates but is tht because his is a 2006 and mines 1997 ? striped bike down today o find that the fuel hose was not tangled but was coming off nipple thing on carb and going straight to the side which restricted the fuel flow after that it was going sooooo much more better but now wen it hits the band it missfires. I use the same plugs as you off the top of my head ?? i know its an iridium. I am considering sending my top end away to Stan Stevens for a 2ml overbore and exhaust matching. At the moment im running a 210 which is standard with a pipercross airfilter full dep system i have tried 220,230 jets and the 230 is a no no as it just bogs but 220 is still a bit boggy but not as bad quite strange. any ideas on the missfiring ? i might need a new lead to the spark cap thing ? ot the cap itself is knacked ? Cheers Paul Link to comment Share on other sites More sharing options...
Guest yamahadt50R Posted April 30, 2010 Share Posted April 30, 2010 and also forfot to mention the top end was only 1500 miles ago. ? Link to comment Share on other sites More sharing options...
satelliteone Posted May 1, 2010 Share Posted May 1, 2010 mmm sounds like the bloody plug to me trying to break down. and i suppose the coil could do the same if say was slightly faulty.. Another thing thats well over looked is the pickup from the flywheel, dead easy to get at, just need to take the flywheel cover off, have a look at it, to see if any rust has formed on the head of the pickup, or even small metal fillings. Give it a good clean. other than that it is starving of fuel. that could be many reasons. Float level, flow, jets/needle position..bla bla bla.. Link to comment Share on other sites More sharing options...
Guest yamahadt50R Posted May 1, 2010 Share Posted May 1, 2010 Cheers Sate, I took the rear silencer off and errrrr was it a mess because the person who had pipe before (my mate) was running premix so as you can imagine the mess and splutter of oil took it all out cleaned the pipe up and re packed it and WOW !!! she goes quick ! like very quick BUT.... it runs alot better if the choke is left on it runs an absolute dream though and that is the main thing I am going to try upjetting it now but I really want a standard front pipe sounds alot better and now im convinced on getting a 2ml overbore from Stan Stephens ! that will be fun to see. Link to comment Share on other sites More sharing options...
gaterade0 Posted June 1, 2010 Share Posted June 1, 2010 hello i can get my dt125r to rev past 12k and it pulls like a train through all gears beats my friends nsr125 and its not restricted and beats my friends aprilia 125mx it can do 80mph all ive done to mine is bigone front pipe pipercross panel filter with 8 motorcross 1 inch round filters put into the airbox to de-restrict it sounds great and i customised a vforce3 reed block off a yamaha 200cc blaster valve quad i still need to upjet as yet to a 250 or a 260 as i no it needs it but my power valve isnt fully open till 9k revs is the power valve wrong cheers Link to comment Share on other sites More sharing options...
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