genesis/exup hybrid

krazyneil · Post by **krazyneil** » Sat Jun 09, 2018 2:08 pm

I recently bought a genesis 1000 which has been fitted with exup top end ,I had a funeral to go to Monday in Doncaster so had to put her on the road quickish
now bearing in mind the first ride was to mot it Saturday ,then it was stripped and matt blacked sunday ready for early Monday ,I noticed on the trip there that it was hesitant /rough around 3/3.5k rpm ,under or over that it seemed fine and pulled pretty good though I wasn't thrashing it lol
so any thoughts on what could cause this ?
seems odd to be just around that 500rpm mark ,if the jetting was out id have thought you notice it all through the rev range

Post by **Stig** » Sat Jun 09, 2018 3:59 pm

Which cdi you using? Maybe it's looking for Exup servo actuator?

krazyneil · Post by **krazyneil** » Sat Jun 09, 2018 4:31 pm

its all genesis except from the barrel/head ect
so its using genny carbs/cdi ect

Graham Crayon · Post by **Graham Crayon** » Mon Jun 11, 2018 10:39 pm

Genesis engine is very picky when it comes to fitting anything other than standard exhaust & or air filters. If you have after market versions of either it will cause the mentioned flat spot at 3.5-4000 rpm. FZ750 engine is the same. Jets, altering needle heights etc will mask it slightly but the whole reason Yamaha went to the exup was to cure this problem. You can either spend loads of time & money trying to sort it, live with it or fit an exup engine complete with working exhaust valve.