running in a 300cc motor

corky · Post by **corky** » Wed Feb 27, 2008 4:23 pm

just got myself a fully rebuilt brand new 300cc motor for the hybrid

BUT
how should i run it in?
how many laps?
got trackdays coming up, thinking i will have to use a trackday just to run the engine in

The carbs are 29.5mm and are running 142.5 jets
i may fit my 35mm carbs to them but what jets should i start with?

any help appreciated

mgtkr1 · Post by **mgtkr1** » Wed Feb 27, 2008 5:40 pm

to play safe i would run the 35mm carbs with 160 mj seen as your running in, assuming you have std airbox. this SHOULD be pl;enty big enough for a start and you should end up around the 150-155 mark i think. elf or mj advised me a bit back and the 150 mj seems to ting a bell. i have been testing some bits out with 35mm carbs (without airbox atm) and running 165 mj with a dark electrode though i havent done a proper plug chop. i can tell the motor is a bit rich on this jetting. running in, dont load the motor, keep revs up/lower gears careful warm up, genourous oil ratio,rich side of jetting and gently add more revs. two twenty mile runs or equivelant should be suffice.

the-elf · Post by **the-elf** » Thu Feb 28, 2008 6:22 pm

Best place to run it in is on a dyno. 10-20 mins and its done then you can get a power curve for it and get the jetting spot on. Are you going to run Lomas exhausts with the 35mm carbs?

corky · Post by **corky** » Fri Feb 29, 2008 10:49 am

a bit skint at the moment spent a fortune over the last month on the hybrid

got a choice of nikkons or gutted kr1s pipes with DEP cans (short ones)

think zeeltronic ignition next at the end of the month....

got to enlarge airbox as well

so may run engine that is in it until i have got all the mods ready then stick them in together with the the 300motor and run her on a dyno.

at this rate may have to sell my road KR1s as the hybrid is absorbing money