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sass34

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G'day everyone, im new to the fourm and have started my first pit bike build and just wanted some tips and info if you have any on my plans and progress. (pics soon to come)

Im starting with a PitPro (i think) with Lifan 4sd manual 125 motor in it.
At the moment i have taken the top end apart and decided to start with a fresh TB High Comp piston (52.4mm with 13mm Pin) with gasket kit and 'moderate lift' race cam, High Rev CDI, re ground the valves and polished and ported the head with new stem seals. I bought a new carby kit http://www.dhz.com.au/buy/mikuni-26mm-racing-carburetor-kit-90cc-110cc-125cc/CARB-001 and will take to the inlet manifold with a dremal to tidy it up and help with better air flow. Would this carby suit my setup??
I will be repainting the frame and adding new graphics and plastics soon with ProTaper bars and new brake/clutch levers also alloy throttle and new grips.
Not wanting to spend alot at the moment on a Big Bore Kit, Bigger head or and other crazy engine mods just a little bit extra power. I only paid $50 for the complete bike so im ahead in the budget already! :)

Cheers for reading!:cool:
 
Nice one mate, seems like you know what your doing. Keep us posted regularly, that carb will suit but might be better going a keihin pe24 later on. Defiantly put some pics up everyone here loves pics, will watch this space for sure.


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hey mate and welcome to miniriders

sounds like you will have the lifan 125 moving along ok and for 50 buck what a bargin

get some pics up so we can check it out

cheers...
 
i probably would not reccomend that carby if your looking for more power maybe a http://www.dhz.com.au/buy/oko-26mm-flateslide-race-carby-kit/CARB-05-26-KIT
but then again maybe thats too much of off and on power for your liking


maybe 26mm is too big? (you need a smaller carb to increase air speed over the carb and jets to get it to work correctly) maybe you will need a 24mm http://www.dhz.com.au/buy/oko-24mm-flateslide-race-carby-kit/CARB-05-24-KIT

anyway the carb you linked to is annoying to work with because the air fuel adjustment is on the bottom where you cant get to it
 
Oko 26mm I reckon is to big and for ease with tuning the mikuni you could grab a flex jet.


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Oko 26mm I reckon is to big and for ease with tuning the mikuni you could grab a flex jet.


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yeah but $70 for the carb and then 30 +postage for the flexijet
may aswell get a oko carb and have better top end power

also what cam are you gonna run? make sure you have matching valve springs
 
I have a stock TB V2 cam for sale if your interested :)
 
Yeah i thought 26mm seemed too big but with the race cam and high comp piston i thought it would be alright considering it came with a 26mm but had broken bits left right and centre.
how is the OKO different? (not really switched on with carbys)
 
yeah but $70 for the carb and then 30 +postage for the flexijet
may aswell get a oko carb and have better top end power

also what cam are you gonna run? make sure you have matching valve springs

Its TB411 Race cam. it says theres no need to change out stock valve springs as it dosn't have real aggressive lift
 
Yeah i thought 26mm seemed too big but with the race cam and high comp piston i thought it would be alright considering it came with a 26mm but had broken bits left right and centre.
how is the OKO different? (not really switched on with carbys)

There a flat slide, so instead of the round slide like they have in the mikunis they are just flat..
makes for a slightly harder to tune (slightly) a little less power in the bottom range but a increase in power for the top end
 
Ok then well what would be best for low to mid range power?

if i go 24mm would that suit if i wanted to add engine mods later?
 
Someone correct me if I'm wrong but the 26mm is actually an oval bore so really is a 22mm at heart and the oko 26mm is round and a true 26mm carb, the flat slide actually gives you better bottom end power, its more on and off as opposed to a round slide which is a smoother power delivery.
I've used both the 24mm & 26mm oko's and different sized Mikuni's. I'm currently running a 24mm oko on a 140 and it works great on that.


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Last edited:
Someone correct me if I'm wrong but the 26mm is actually an oval bore so really is a 22mm at heart and the oko 26mm is round and a true 26mm carb, the flat slide actually gives you better bottom end power, its more on and off as opposed to a round slide which is a smoother power delivery.
I've used both the 24mm & 26mm oko's and different sized Mikuni's. I'm currently running a 24mm oko on a 140 and it works great on that.


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Spot on dude.
 
Righto thanks for the info!

Ill see how I go with the 26mm as its already on its way from DHZ an if its not what I want ill go for the 24mm OKO for sure. Any good exhausts that would work well with what I have or is that just wasting money?
 
Ok great news!

I got a full refund for the 26mm carb I ordered (Thanks DHZ!)
Will be looking around for a better option so if anyone knows of a good
priced 24mm carb kit let me know please!

Cheers :)
 
Hi sass34 Welcome to Miniriders i have used the Oko 24mm flatslide on a lifan 125 as it was said the power is on or off with power delivery. I have also used a Mikuni VM24 roundslide carby on this engine it worked very well with that. This engine was not standard it had a 7mm lift cam the head was ported and polished, hi comp piston and bigbore exhaust. It worked well with a 20 pilot jet and a 97main jet with the needle clip in the middle groove with a uni-filter airfilter.
 

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