jetting

[mcronson]

Ok heres the deal,I have a 80 xs,and on those carbs the idle air screws are recessed into the carb body,

well one of em seized and I couldn't get it out,

So I bought a set of carbs from a 78,
I also have is a straight pipe exhaust with foams on the individual carbs,and It runs hot(no surprise there)

I am not currently riding it except if it is cool outside(rd400c also in my stable)

I looked at the carb facts and saw what the stock jetting is.
Can anyone give me some advice on which jets I need to replace,

Do I need to replace just the mains and pilots or do I need to replace all of the jets in the carbs.

My plan is to find a used 4 into 1 eventually at a reasonable price.

[mcronson]

jetting

ok I looked up the forum topic about jetting recomendations,It appears all the jets in the 78 carbs are bigger than the 80 models
80 is 115/120 mains and 42.5 pilots.

78 is 137.5 and 45.0

any suggestions on sizes I should be running?

Again individual foams and open header (mostly)

the jetting guide says I should go up 5 sizes minus 1 for this config,

but I am not sure I am reading this right

I am guessing the jet sizes go up in increments but have no idea what those increments are

[John]

The main jet increments are 2.5at a time. ie 135-137.5-140 etc Mikuni has a web site that helps to sort out the jetting. I believe you can find the link in the maintenence tips here.

[mcronson]

Ok thats was what I needed thanks a bunch.