Tricks of the trade

[unit_mx]

Smoothing out the castings improved flow = improves throttle response.
Irk will decrease your engine lifan as the motor is reving out harder however its in balance with reducing the weight placed on the crank.

MORE FREE STUFF:

Check out this article:

Dirt Bike Mods - Pit Bikes, Mini bikes, MX Bikes

Very very good reading!!!

 

[Shroomin]

would i need to tune my bike after these basic mods, i dont see why i would have to.
cheers
p.s great link unit

 

[unit_mx]

No you should be right mate , I didn't need to so it should run fine.
Hope that helps

 

[WyldOne]

Good thread!

 

[jarrah140]

Great thread, some really useful info coming out of the woodwork! I see a few questions related to porting and polishing so I thought I might share this, there's some very helpful info here :

DIY - Basic Cylinder Head Porting -Standard Abrasives Motor Sports

And this other Link is to a general "Bike" Tips page. This place is a great site to have in your Favourites! It's helped me plenty! The Guy who owns it seems a bit odd sprouting religous quotes here and there but all in all a very informative repair / tips guide. Check it out, you'll see what I mean!!

Motorcycle Repair Course

 

[rotn50]

Awesome thread mate, im a tight arse(or broke arse more like it) and these mods are dirt cheap and very useful, hope to be performing these soon Cheers

 

[whitty]

can anyone give me anything indepth in relation to 3)measure the diameter of the engine head inlet and the manifold inlet part of the carby ,write it down as the we will port this out to match the two inlets...or just the whole process am i am a bit confused on what we are matching...

 

[twisties]

whitty im not 100% sure myself, but from what i understand its like this:

get a caliper or something, and measure the diametre of the hole in your engine block that the manifold goes into.
you want that hole to match the size of the pipe between the carby and the engine block itself.
so basically you are sanding it etc to widen it up so that there is no restriction between the carby and the engine block.
hope that helps!

 

[gards]

great tips thanks

 

[DvDRip]

the IRK will make you lose a lot of bottom end torqe, it'll just make you're bike rev faster

 

[headsmess]

whitty im not 100% sure myself, but from what i understand its like this:

get a caliper or something, and measure the diametre of the hole in your engine block that the manifold goes into.
you want that hole to match the size of the pipe between the carby and the engine block itself.
so basically you are sanding it etc to widen it up so that there is no restriction between the carby and the engine block.
hope that helps!

best things using bearing blue or ink on both faces, slip in some paper and screw it on... pull it apart and look thru the paper against the light...
then you can see if the holes are actually in line and what material needs removing from where...

 

[KLR125]

great thread.

what about for the people who are half poor.

if you got 50 bucks lying around, go and buy an aftermarket performance cdi and coil

the cdi will send a larger pump to the coil wich will give a larger spark

match it to a good spark plug and it will make a diff

 

[brap]

sick thread mate
im gonna port and pollish my manifold tomorrow
cheers

 

[gonetopilbara]

I have no idea if this applies or is relevant to the small size of pitbike wheels, but on our motocross bikes we used to cable tie each of the spokes where they crossed over.

 

[dime_megga]

yer top post unit one question though, how do i port the hole in the head with out gettn metal dust in there??

you dont port no head, u port the INTAKE MANIFOLD the thing coming out of the head into the carb.

 

[dafunk]

if your sick of ripping valves out of tubes , and are to tight to get a rim lock .
stick a couple of short self tapping screws thru the rim and into the tyre ,make sure they dont go into tube .
about 4 on the back and 2 on the front

 

[MuddyMini]

Glad to have found this thread

I got a rough looking intake manifold with my new OKO carby today. Well, from what I've read it sounds like they are all rough as guts

So it must be time to make use of that Dremmel Kit I bought years ago!

Here are a few pics to show what a manifold looks like (brand new) and what part of it needs tidying up (ie. the entire inside bit!!)

I'll put some more pics up after the job is done

 

[Motovert Pro]

Believe it or not muddymini that is actually a good manifold.

 

[MuddyMini]

Believe it or not muddymini that is actually a good manifold.

HOLY CRAP! Well I'd hate to see what a really bad one looks like then This manifold actually makes my Mikuni look flawless

 

[GenuineRider]

i gave the porting trick ago on the manifold, turned out alright, all smoothed and polished
ill post pics later