ZRX1200 Carb Conversion

[IanDMacDonald]

Wouldn't adding a steel make it worse?

I'm not sure, Mike. I DO know that originally upon acquiring the bike, the owner had an extra steel in there. All I know is that I cannot adjust this thing to get it from lurching, when putting it into gear.

[Schming]

Ian, is the cable streching upon use ? Maybe go an 1/8 turn at the arm ?

[IanDMacDonald]

Ian, is the cable streching upon use ? Maybe go an 1/8 turn at the arm ?

Nah. Brand new cable. Not a cable issue.

On another note: I pulled the plugs, and certainly FAR from running rich. Very lean. I'm at 140 mains. I may need to go up.

[Bonz]

Yes and no going up on the mains.
-What position/groove is the clip on the needle.
- How does it pull/feel once you're up on the main accelerating hard above 6,000 or 7,000 rpm. Reading your previous post today, appears it's running well throughout the power band.

If it pulls good at high RPM acceleration, richen up the needle first, IMO/IME.

[IanDMacDonald]

Yes and no going up on the mains.
-What position/groove is the clip on the needle.
- How does it pull/feel once you're up on the main accelerating hard above 6,000 or 7,000 rpm. Reading your previous post today, appears it's running well throughout the power band.

If it pulls good at high RPM acceleration, richen up the needle first, IMO/IME.

I think I'm in the 3rd position down from the top. From memory of your previous post, I want to lower the clip (#4 slot down from the top) to richen it.

I think I'll go one more turn on the A/F screw, and drop the clip, and report back.

[Bonz]

Excellent information. The bike is 2.5 turns on the pilots, if it's idling well, my move would be to leave those alone for the moment. Definitely a good next change is going to the fourth clip position.

The AFR gauge change at idle on the ZRX 1200 shows .5 to .7 of a point richer or leaner with a half turn on the pilots. For what it's worth I've run 40 and 38 pilots in those carbs, and the change amount is basically the same with a half turn.

My thought ia a full turn on the pilots and a clip position richer at the same time would take a bigger swing at it then may be expected.

Main thing is you know what you're looking for on the plugs. If it's telling you to do a full turn along with the clip position adjustment, by means go with what it's telling you. Either you undo some richening because it was too big of a swing, or if you don't adjust as much and it's not enough, you're doing another adjustment either way. Kind of the beauty of doing all this isn't it, lol.

[IanDMacDonald]

Excellent information. The bike is 2.5 turns on the pilots, if it's idling well, my move would be to leave those alone for the moment. Definitely a good next change is going to the fourth clip position.

The AFR gauge change at idle on the ZRX 1200 shows .5 to .7 of a point richer or leaner with a half turn on the pilots. For what it's worth I've run 40 and 38 pilots in those carbs, and the change amount is basically the same with a half turn.

My thought ia a full turn on the pilots and a clip position richer at the same time would take a bigger swing at it then may be expected.

Main thing is you know what you're looking for on the plugs. If it's telling you to do a full turn along with the clip position adjustment, by means go with what it's telling you. Either you undo some richening because it was too big of a swing, or if you don't adjust as much and it's not enough, you're doing another adjustment either way. Kind of the beauty of doing all this isn't it, lol.

Yeah, I was looking super-lean, at 2.5 turns on the A/F screws, and 3rd clip position down from the top. I think I'll go half a turn out, as the A/F screws are starting to feel loose at 3 turns. Anything more, and I'd be concerned. And, I'm dropping the clip to the #4 position from the top.

[Bonz]

Sounds good.

[Bonz]

Sounds good. Good call on going up on the pilots if three or three and a half turn starts to feel loose. No choice but to do that. 40's will make a difference in cruise mixture. 40p's flow 11% more fuel vs 38's. Since that's one of the main contributors to cruise, you should see some improvement with those on top of going richer on the clip.