need help with jeting

[RivaCrB23]

I opened up my carb today and saw my main jet had the numbers 052 on it. Does this mean this is the stock 230 main jet? The jet i pulled out is the one that the needle slides in and out of. It sits right in the middle of the carb. The reason I am trying to determine my jet is because I have a full fmf exhaust, k&n air filter, vforce reeds with spacer. I also just discovered the bike i bought was ported it has auxillary holes and a larger intake. what jet should i be running for this bike? I alos have the air box lid off. Thanks

 

[nofxfan125]

Well, what does your plug look like?

 

[RivaCrB23]

The piston is blown on the bike so the plug looks like Hell. I just dont understand what size main jet I have since the number 052 doesnt mean anything to me. I bought the bike wiht all these mods done to it so I dont know what carb work has been done. Like I said I didnt even know it was ported lol. The end result is My piston did blow up due to being lean so I guess if I throw a larger jet in it would not hurt?

 

[burnin'_oil_2001]

that sounds like a pilot jet number. wow i am stumped- this came out of the stock carb- from the main jet area? are you sure that you did not take the needle jet out?

 

[RivaCrB23]

It is listed as number 9 on the diagram for yamaha parts under carb. It is the jet that the main throttle need slides down into from above. It has that number stamped on the front where the gas would flow into. It also has the mukuni logo stamped there

 

[burnin'_oil_2001]

my research leads me to believe that you have the main air jet as it is stock a .5 for the vm26-74, here are a couple of links for you to look at:

Mikuni ATV Carburetors
VM  ROUND SLIDE STANDARD SPECIFICATIONS
Mikuni Tuning Components
Mikuni Tuning Info
http://www.carbparts.com/mikuni/vm20_44.gif ----- exploded view of carb

 

[Awk08]

your not looking at the main jet, it's the first thing you see when ya pull the bowl, its a hex jet, takes a 6mm socket to get it out, and has the platic baffle thingy slid over it, see what size it says on it, and get back to us

 

[luxuriespremier]

Thats the exact one we are talking about. Needs a 6mm it has a plastic baffle looking thing around it and its the only hex jet in there lol. I have no idea why it has that number on it?

 

[245stroker]

Try to take a clear pic of it and post it up. That may help some of us out and determine what it is

 

[gonzo]

the person that set the machine up at Mikuni did 052 (backwards) instead of 250 you need to measure the dia. of the hole or like they said post a clear pic.