Ok I know this sounds bad, but I have been tunin on my ds and its going really well. ( draggin 450s) . And as anyone would know, once you start going faster you cant stop. I did the omr carb mods and stock intake tube with uni filter (no box). Ported the intake, and put on a 15 tooth front sprocket. Today i got the bright ide to make my own endcap. Worked out pretty good, 3in tip in stock cap. Sounds great. Just took it for a ride and it wouldnt hit the rev limiter in 3 or 4th and i didnt dare try 5th...I figured it was too lean, so i checked and its got a 180 jet in it....And i couldnt wait till 2morrow to get a new jet, so i drilled it to 5/64.....Feels alot better. So if I were to go get some jets, what numbers would be colse to what i need for tuning?......Surely someone has drilled their own jets before!....lol

 

I did see this info. somewhere b4.....the jets are in mm

the formula was like 180jet= 1.8mm x 100

1.8 divide by 25.4= .07086

1.8mm=.0709 of an inch

blahhh, blahh, blahh...here is a chart

 

5/64 is equal to a 195DJ or a 185 mikuni.
If you are running an open airbox, you need to change the air jet to the emulsion tube.

 

Thats weird [img]i/expressions/face-icon-small-confused.gif[/img].....cause the chart put it at a 198 or 200

drills tend to put a bigger hole than the bits actual diameter

 

OMR, please elaborated. What and where is this thing i need to change. Sorry, not an expert at this carb yet. Thanx

 

The main air jet in the DS is a number 120.
The main air jet in a Quest or Traxter is a number 40
Part number 707200187
120 is actually a .037" hole.
40 is a .022" hole

The 40 still supplies all the air needs for the emulsion tube, but maintains the negative pressure to supply the needed fuel for high rpm's with the lid off.

For times that we are riding with the lid-on, jet accordingly, but there is added power at high rpm's also.

With the air snorkel removed from the front of carb, when looking straight into the carb venturi, the air jet is at the 3 o'clock position. Same side as the throttle cable. You will need a small screwdriver to remove the jet. Cost is around $8.00
When reinstalling, do not overtighten, small threads.
This will richen the mainjet by about 3 jet sizes and not allow the top end to lean out.

 

Assuming the drill holds its size in the jet, a 5/64 drill measures .0781".
Multiply that, by 25.4 to get mm.
.0781 x25.4 = 1.984
Move the decimal place over 2 to the right and you end up with 198.4 jet.

 

Ok, so i need to get a 40 jet for the air bleed.....And i need jets somewhere around 190-210....does that sound right?