2008 PitPro Lifan 125

[my67xr]

nah it's not a factory built in rev limiter, lol

yeah, the soft/weak valve springs let it get valve bounce
everything is moving so fast that the valves bounce off their seats due to inertia etc

[video=youtube;_REQ1PUM0rY]http://www.youtube.com/watch?v=_REQ1PUM0rY[/video]


you can upgrade the Zongshen heads by using some YX160 springs with a 1mm shim under them
or buy an Akunar upgrade set

 

[stoozo]

So that would theoretically create more power too if the springs aren't going all over the place! is that correct?

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[stoozo]

Hmmm next time go down to see Chad will grab that head down there...

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[my67xr]

i'm not sure what springs the YX150 head have, if they're the same rate as the YX160 springs

 

[stoozo]

Right will have a look at akunar!

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[stoozo]

95% done bash plate and rear wheel adjustment and mixtures and its done! Got it through all gears just now :thumbup: Craig is posting up a vid in a second!!

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[my67xr]

and a quick video of it running untuned atm,
with some flames from being over rich, or exhaust gasket leak at the head
click on it to view-

 

[xLOCOx]

LOOKS pretty hot now stu!!!!
+reps mate top job!

 

[Rikchick]

It's a dark video but shows the flames nicely hahaha, doesn't sound too bad except for the pops.... Sort that out and it'll be sweet as


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[Blender]

Looks sweet, are you going to upgade the carb?

 

[my67xr]

It's a dark video but shows the flames nicely hahaha, doesn't sound too bad except for the pops.... Sort that out and it'll be sweet as

it was taken just at dusk, the flames weren't as visible during daylight.

i reckon the China 22mm Mikuni is the perfect size for a 150, and it would make the bike very usable anywhere you want to take it.
but then again a tuned 24mm OKO could give it a little more punch too

 

[Blender]

I would think the 22 would be a tad small for the 150? I always thought they were best suited to the 125-140cc engines? I reckon go the 24 OKO, cant have enough power, lol

 

[my67xr]

a standard 125 is happy with a China Mikuni 19mm, they give you quick throttle response, and rev out pretty well, the 22mm are a bit big, best suited for top end use.

and don't forget that the Braaap 190's come with a 22mm

 

[my67xr]

a standard 125 is happy with a China Mikuni 19mm, they give you quick throttle response, and rev out pretty well, the 22mm are a bit big, best suited for top end use.
they are a bit harder to find though, the Mikuni 22/26 's are everywhere

and don't forget that the Braaap 190's come with a 22mm

 

[Blender]

Yeah, I have a 19mm carb sitting here in pieces, I might swap it over, and see how it runs. It'll help with bottom end right ?

 

[my67xr]

yeah the smaller bore carbys will increase velocity, and also help with the fuel/air atomisation

the worst thing about the smaller china carbs is they aren't machined too well, check all the mounting faces are flat

 

[stoozo]

Lol lol....yeah but with the clearance issues with this carb and bore hence the fins missing....might be able to fit a 24mm oko but will have to remove the fuel tank and head and bore!!! Sorry its upside down stupid phone! Not to keen on looking for the right shaped manifold

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[my67xr]

the pic is the right way up
need another one from the front/side to show the clearance issue better

 

[Blender]

I would just get a plastic spacer like what you use for the carb, and just use it as a spacer in between the head if you need it for the OKO

 

[my67xr]

raising it would give the top of the carby clearance issues to the tank
it almost would need to have the carby hanging out at 90° to the engine