PWK/OKO Carb modifications

[oakerz]

Hi all,

I seem to remember reading on the forum about some modifications involving opening up, via drilling, various holes in the carb body of PWK/OKO variants. Can anybody send me a link or an explanation as I haven't had any luck locating the thread.

Many Thanks,

Mark

[Danger]

is this an old carb or a new one as i had the same issue with mine only to find that the newer ones are already done i have an email about it that i will try an put up, also your float need to be between 19 an 22 mm remove float bowl place carb on it side an tilt it back abit then measure from bootm of carb body to end of float if i cant get it printed off i will write it out then post

[Danger]

as luck would have it was talking to Harry Barlow about the work he is doing for me..... he asked if i'd done the mods to the carb to stop fuel starvation..... It's a real common problem.

anyway here's what you need to do!


Strip the carb and put all the pieces on a clean cloth.

Remove the float and remove the float needle.

The Chamber the float needle sits in has two holes that run across it, one pointing towards the bellmouth and the other towards the inlet

run a 2.0mm drill through them to open them up and let the fuel through fully.

Next, and this is more tricky, if you look into the body of the carb with the slide removed, you will see a brass tube protruding where the needle goes in. Just behind this on the manifold side is a very small hole, almost like a pin prick. This needs to be drilled out with a 1mm drill. You can remove this middle section of the carb by removing the two cross-head screws accessed from the float chamber, BE CAREFUL THEY ARE SOFT AND CAN BE DAMAGED EASILY.

I did this as well as removing the lug in the float bowl. Together with correct jetting it then worked perfectly. hope this helps

[Danger]

i got this sent to me an hope it helps you , like i said mine was already done an goodluck

[soosh]

Are all the BGM ones allready done then now do you know? I had this grief and nipped my engine up due to this.

[Danger]

im not sure m8 , was just told that my oko may of needed this done but it was already done not that it mattered to me as i couldnt for the life of me get it set up anyway now sold it

[oakerz]

Excellent thanks for the responses.

It's an oldish carb, ScootRS 2001/2 vintage if my memory serves correctly. It's always been a poor starter and languished on the shelf for a long time. The rest of the jetting seems fairly good once running on this particular motor and I have never suffered the hot starting issues others seem to have so I am thinking of having another at go at getting this working better, nothing ventured nothing gained!

Many Thanks.

Mark

[dapper]

Excellent advice given here

http://www.miniriders.com/tech-talk/268 ... -mods.html

[soosh]

Mine was never good at starting from cold either,guess the choke jet maybe small. Starts perfect with dellorto. When had it dyno`d,it kicked out 2hp at 6000rpm than the dellorto.Chucked out twice as much fuel on the runner boards too though! Good carbs when you get them sorted.

[minotaur]

i did all of what is written on the miniriders forum as posted earlier and it helped but my float heights made me either too rich or i would run out of fuel at full wack, i them ground off the float stop at the bottom of the float bowl and all is well now