The yellow and blue need to be switched the black is a common with to both those two colors. Why are you doing left side mount why not right side mount?

I went ahead and made a right side mount because I was in a rush , I had to go riding this afternoon I was going to do a left side as there is more room ,Erbman said it was blue-black swap for the left side mount.



I also shortened the stock Idle screw ,just tigged it back together.



Back home after a couple hour ride with the new carb, sooo nice Can't weight to fire the stock carb in the trash.. I got the HSR42 off eBay for $103.00 super deal looks like new inside and out.

Good job on the idle screw I was going to do the same with mine but my carbs already had the short screw in them.

L&R from Poland again.
I checked my HSR42. I am schock
Pilot jet: 45
Main jet: 190
Needles jet: 97 and third clip
Nozzles pump: 70
PMS 3,5 turn out

What dou You think about this adjust?

PS Specjally regards from wykrzyknik to DocShadow

Not sure what your elevation is but that sounds kind of rich to me. One of my bikes (the 07) I am at 3 on the needle, 165 main, 25 pilot air screw out 2 1/2 turns, The other one (05) is 3 on the needle, 160 main, 25 pilot, and the air screw out 2 1/4 turns. BUT my carbs are 45's.

choppers_polska wrote:
L&R from Poland again.
I checked my HSR42. I am schock
Pilot jet: 45
Main jet: 190
Needles jet: 97 and third clip
Nozzles pump: 70
PMS 3,5 turn out

What dou You think about this adjust?

PS Specjally regards from wykrzyknik to DocShadow

And what kind of mileage you getting, mid 20mpg?
You are too rich on every ckt, unless you have a huge intake air leak.
You don't need anything bigger than the stock pilot jet (#25) and in some cases can go to a 22.5
Main jet nothing bigger than a 167.5
pump nozzle is also way too big the #50 is more than enough .
and your pilot screw is out of spec as well, would never be more than 2.5 turns out
and as far as the needle, counting from blunt end, 2nd or 3rd groove, and I suggest never using an extra washer, this could cause the needle slide holder to bend slightly, and if you remove the extra washer it would cause the needle to have a little slop, which is no good. Besides, there are other options to tune with to not have to use an extra washer

I've helped to set-up a few dozen 42's

I would start with new plugs as well, good chance they are fouled running that rich.
Always, always start the pilot screw at 2 turns out from a light seat, and the same if ever changing out the pilot jet, the 2 turns out is a baseline start, you can set the idle screw a little rich to start so as to not stall on a cold engine, but after about 15 minutes or so of riding, re-adjust the idle knob to correct idle rpm. Highly suggest you go to the Mikuni site and read the tuning manual for the HSR carb

Curt wrote:
The yellow and blue need to be switched the black is a common with to both those two colors. Why are you doing left side mount why not right side mount?

No Curt, there really is no common. The yellow wire is the center tap. it is because of this wire that determines which side of the potentiometer has the greater or lesser voltage to the ignition module which causes the timing curve from CT to wot. The blue and the black are the end wires, so if mounting on left side, the potentiometer is now turning in reverse, so the end wires need to reverse, not the center tap, center tap has to be the constant.

3 UP wrote:
Which wires are changed for left side TPS mounting? Erbman you out there , I know you know

Thanks for any help

blu and black if mounting on left. yellow is the center tap which remains the constant. since the blu and black are the ends, and now the potentiometer is turning in opposite direction than stock, then it's the end wires that get reversed

s&scustomcycles.com I think is trying to get a kit together for R* with a mikuni 42 carb and shoulds have them soon it's a total kit to bolt on. check into it.

whitegold wrote:
s&scustomcycles.com I think is trying to get a kit together for R* with a mikuni 42 carb and shoulds have them soon it's a total kit to bolt on. check into it.

yup, including the standard 97 needle and the 98 needle, mains, pilots and pump nozzle options and with Yost power tube. Fuel line and filter as well But no TPS mods