edge Posted March 15, 2008 Share Posted March 15, 2008 I blagged a replacement CDI but it wouldnt start (wrong year aparently) stuck the old one back in runs OK but still holding back at 4000 could it be the Throttle Position gizmo on the carbs changing the timimg as the carbs open? Im going now to beat it with a big stick CLEESE STYLE and reread the Haynes to see if that sheds any light. Link to comment Share on other sites More sharing options...
billa65t Posted March 15, 2008 Share Posted March 15, 2008 I blagged a replacement CDI but it wouldnt start (wrong year aparently) stuck the old one back in runs OK but still holding back at 4000 could it be the Throttle Position gizmo on the carbs changing the timimg as the carbs open? Im going now to beat it with a big stick CLEESE STYLE and reread the Haynes to see if that sheds any light. Hi if the carbs are clean and you have checked that the emulsion tubes are clear and the main jets are also clean and the right size check your needle position and try moving the clip down or up one position from where it is now. Link to comment Share on other sites More sharing options...
mickyprrn Posted March 18, 2008 Share Posted March 18, 2008 I've already posted this in your original thread added here in case you missed it don't know if you're sorted but i had very similar fault with my '93 yzf750 tried all the things mentioned in this post & more. I ended up taking mine to the Dyno Centre in Northallerton. Stuart the guy who runs it used to race yzf750's in BSB is very helpful & pretty much knows everything there is to know. I'm sure if you give him a ring he'll be able to help. if it helps when speaking to him my bike was the YZF750 with vance & hines paint job i'm sure he'll remember it.... www.dyno-centre.co.uk Workshop: 01609 760466 Mobile: 07932 493766 Link to comment Share on other sites More sharing options...
jones2007 Posted May 28, 2008 Share Posted May 28, 2008 h just wandered if you have checked the exup valve ? common fault on these apparently they wont rev past 4000 Link to comment Share on other sites More sharing options...
SNIFFER Posted June 21, 2008 Share Posted June 21, 2008 h just wandered if you have checked the exup valve ? common fault on these apparently they wont rev past 4000 Hi, Just wondered if you rectified the flat spot in the end ? My YZF750R has developed the same problem after an engine rebuild at the dealer. ( pistons , rings , valve stem seals etc ) So sent it back and they replaced the carb needles but it still does it. Bearing in mind the bike did not have this problem before going in for engine rebuild. I dont think they know whats wrong to be honest Link to comment Share on other sites More sharing options...
mr benn Posted June 26, 2008 Share Posted June 26, 2008 sounds very much like Exup needs stripping, cleaning, greasing and setting up Link to comment Share on other sites More sharing options...
Moderator Beezkneez Posted June 27, 2008 Moderator Share Posted June 27, 2008 would hedge a bet at emulsion tubes or exup valve Link to comment Share on other sites More sharing options...
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