quick jetting question

[chips]

well just got a701 61x stock bore with a 650 case and im gunna be putting my riva red pipe on this motor. its got a 44mm carb with a 125 jet in it i beleive. what size jet should i be using??

 

[chips]

i think i have a 145 and a 150. should i be using one of those??

 

[Matt_E]

There are two jets in that carb (Main and Pilot).
If you have a 125 main jet now, I seriously doubt that a 145 or even 150 would be appropriate.

Check here for a similar setup to yours: http://www.x-h2o.com/threads/19403&highlight=database

 

[chips]

o deng.. so do u think a 125 might be too rich? i havent rode it yet to see how it runs with the 125.

 

[Matt_E]

The pipe will require larger than stock jets.
I would not try to run the engine with the stock jets and the pipe, because it will run too lean, potentially putting your motor at risk.
Just find out what jets you need and do it right.

 

[chips]

ok how exactly do i find out which one i need then?

 

[Cliff]

call riva and see what they recommend. jets are cheap and rebuilding motors isnt

 

[Matt_E]

ok how exactly do i find out which one i need then?

Did you check the thread I linked for a similar setup with jetting suggestions?

 

[Mark44]

Like this
http://www.x-h2o.com/threads/39846

Mark44

 

[chips]

yea i checked out that thread, i think im going to try a 140 and see what happens.

 

[chips]

well i gave the 140 a try and it ran good but on the bottom end it would bog out a little before taking off. top end was very fast. plugs are a little darker then they should be. should i try a 135 or should i change the high/low speed screws? this is my first time tuning a carb so not sure where to start.

 

[wayne]

140 should be your main jet. what are you running on you pilot? should be around 125.

 

[chips]

i beleive its stock.. i didn't even think to look. which i think stock is 100. is that my problem?

 

[kevbo]

I have set up stock carb 6M6/701s with stock and ported cylinders. All of these required a 120-130 pilot depending on popoff and pump load. Its a fairly safe bet to start with a 125 pilot, 65 gram spring, 1.5 (stock) needle, and A 150 main with 2 turns out on the top screw. For best response use a pilot that makes the engine gurgle slightly at 1/4 throttle.

 

[chips]

alright well ill check which pilot jet ive got in there now, and how do i know what gram spring i have??

 

[chips]

mk its got a 120 pilot and a 140 main. so what do i need to fix my problem? adjust the low speed screw?

 

[chips]

anyone??

 

[SUPERTUNE]

I have set up stock carb 6M6/701s with stock and ported cylinders. All of these required a 120-130 pilot depending on popoff and pump load. Its a fairly safe bet to start with a 125 pilot, 65 gram spring, 1.5 (stock) needle, and A 150 main with 2 turns out on the top screw. For best response use a pilot that makes the engine gurgle slightly at 1/4 throttle.

Kevbo gave good advice...Start with what he suggested. Then lean down as needed.

 

[chips]

ok so i shouldnt have to mess with the low speed screw at all then?? how do i know if i should adjust that?

 

[kevbo]

The bottom screw is for idle, you can set that on the trailer. The rpm will change as it is turned. Find the fastest setting and open the screw until the rpm slows and that will usually be perfect. Always readjust this after any pop-off change.