test ride rebuilt yx150

[sean01]

this is my sons bike, i just rebuilt the engine with new rings, 160 barrel and 160 gearbox.
only mods are it has slightly more compression, OKO 28mm carb, china power pipe and an IRK(which i hate).
its running 14/37 gearing and feels pretty strong.

so this is pretty much a test run and quick run in ride...

after this ride i will be rechecking the valve clearances, checking the cam bolts and retarding the IRK pickup timing a little(try and broaden the power band)

and if youve seen some of my posts about a carb im having trouble with, this is it.
youll notice sometimes it has a hesitation, well thts the best i can get it...
its running a 52 pilot, any lower and it gets worse.

oh and dont mind my young fella, he just loves the sound of bikes..haha

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[DvDRip]

sounds good man, what is this china power pipe?
does the young lad ride yet?

 

[sean01]

yeah my son in the video is only 4, iv got him one of those 49cc quads to learn on.
my son that owns the bike is 13... its just a bush rider, no racing...

the exhaust is like this 1 32mm BIG BORE EXHAUST FIT CN KLX110 SDG PIT Dirt BIKE :eBay Motors (item 160375542194 end time Nov-07-09 18:38:17 PST)

 

[thump*140]

my 140 sounds just like that... you running a H-bomb pipe on it??
man, 52 pilot is HUGE!!! Mine has similar symptoms at moderate throttle settings... kinda pops and farts without picking up at all.... all it takes to clear it is a very minor flick of the clutch and it's gone and your outta there... I've tried everything i can think of, and even the mob who dynoed it couldnt tune out the dead spot at moderate throttle...
it's a weird one, cause if you stage with a few revs, then hold the sucker past half throttle, it revs cleanly from idle to red line... anything from about 1/2 throttle to WOT, it pulls fine... anything under half throttle, or perhaps a little closer to 1/4 throttle, the dead spot appears and doesnt go anyway until you flick the clutch... Just a theory, but i think the needle jet cavitates when it does it... (ie slaps around inside the main jet, and the fuel delivery is intermittent, and meters in different quantities as the needle "pendulums"... It literally only does it when your pootling about... get up it, and the dead spot doesnt exist... tis a weird one, and i cant find a way to tune out an "intermittent" problem that is only related to light throttle settings... normally it's the other way round... so i'm thinking jetting is ok, it's actually a physical affliction or defect within the carby itself...
i also havent tried doing something with the vent on the choke side of the carby... wondering if tapping a tube/line from a valve cap breather into it, will work like an old boost bottle on the old yamahas....
it may also be the fact the OKO's dont have enough holes in the emulsion tube, and cant generate enough of a "spray" at light throttle settings, but can do so, at heavier throttle...
NFI mate, 28's irrit me unless they're on WOT, then they're worth every cent.

 

[sean01]

well can you do me a favor and try a pilot at least larger than 42 in yrs, be interesting to see what yrs does...
the 28mm oko we have on the 196 now is spot on, not bog spots anywhere.. its running a 48 pilot and 115 main and i think its a JJF needle. still needs to go higher in the pilot tho as the mix screw is only out about .5 of a turn...

my carb is no where near as bad as it was with the 42 pilot... you can hear in the vid sometimes id flick the clutch, thts where the bog spot is but funny thing is its not there all the time.....

also wat needle is in yr 28mm

oh forgot to add, does yrs idle like is has a big cam in it? mine does and im guessing its because of an internal vacuum leak... im really sus on the choke circuit

 

[sean01]

ok just redone the valve clearance and retarded the timing...
seems heaps better...

also theres not much clutch work in this vid its all just throttle, just to show that the bog spot is almost not there compared to before these vids with a smaller pilot...

haha, my son is going to need to man up now, because it aint the same bike to ride as before...

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[themountain]

...haha, my son is going to need to man up now, because it aint the same bike to ride as before...

he get used to it quicker then you think...hahaha...my lad did, he`s now running circles around his poor father

Engine sounds great...nice rev!!