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running in a 300cc motor

Posted: Wed Feb 27, 2008 4:23 pm
by corky
:D just got myself a fully rebuilt brand new 300cc motor for the hybrid :)
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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 :cry:

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 :)

Posted: Wed Feb 27, 2008 5:40 pm
by mgtkr1
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.

Posted: Thu Feb 28, 2008 6:22 pm
by the-elf
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?

Posted: Fri Feb 29, 2008 10:49 am
by corky
a bit skint at the moment spent a fortune over the last month on the hybrid :(
:D

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

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 :(