bengo

Thanks for the warm welcome. Im not much chop on the computor and only a one finger typer. I placed stickers over the 400 on the rd so the cops couldnt tell the capacity while on L plates. Kat is short for suzuki katana. T-rex is nickname for a yamaha trx. Bush means off road,its probably clear as mud now lol.

No there was none fitted on disassembly and the crappy clymer manual does not show one. It was burning heaps of oil before so I pulled the sleeve back out and smeared silastic between inside of sleeve and crank this slowed usage of oil somewhat but not completly. where does "o"ring go crank side or gear side and would burning the oil be the cause of the rough running and poor performance?

Just found this site and joined yesterday. Im dobbo but on here Im bengo (dobbo was taken) Im 50 and been riding bikes since I was a boy. I started riding in the bush on bultacos and huskys my first roadie was a rd400 with stickers over the 400 (learners are restricted to 250). My next roadie was a rickman honda followed by a suzuki katana 1100. Wrote the kat off and then done up a rd350lc sold that for a trx850 and also got back into dirt bikes with a yz125h and a ty250a still got the yamy dirt bikes but sold the t-rex for a bmw r1100s. Looking forward to converse with you all regards bengo.

Thanks for the welcome and rapid reply oldgitonabike. I should have been more descriptive,I have cleaned out the jets and all passageways ect the slide does raise when the Idle screw is wound in and will idle if you open the throttle slightly. Under no load it revs cleanly to full revs,however when riding it has no power from 1/4 to 3/4 throttle run rough (splutters and surges) but it clears up at full throttle and then it really flies. It is also consuming a slight amount of gearbox oil,I have replaced the crank seals however had to reuse the sleeve the seal runs on as they are no longer available from yamaha anymore. It has new bore piston and rings and starts easily it has got me stumped.

Ive restored a 1981 yz125h and cant get it to run properly. It runs fine flat out at full throttle however it has no power and runs rough in the midrange and will not idle no matter how I ajust the idle and air screws. I have fully rebuilt the motor. Also can anyone tell me the slide and needle sizes thanks in advance bengo new member. PS its an Australian model with a 32mm mikuni carb.