Lean carb question

[tothemax93]

I had Danny do a carb scrubbing for me, So all my internal stuff is as it should be. I have a morleys carb kit with marks 4-1. I'm kinda starting over with my adjustments because each carb seemed to have a mind of its own. That why I had Danny go through them. So I put them on a week ago, and got a chance today to run the bike and see how it ran.

This is my current set-up
152.5 mains
stage 7 needles at 4th clip
A/F at 3 1/2 turns out.
air correctors
floats at 17mm
stock springs, 4 coils tied back


So I rode around 20 miles. I Went through all the phases, from hammering to red line, cruising, etc. It felt really strong from 4,000 to red line. I was satisfied with that. Between 2 and 4 thousand it was a bit ruff, and I had some popping on decelaration. I checked the plugs and they showed very lean. I've read and reread the post on carb set ups, and how to tune them. From what I've read, if the A/F needs to be turned out that far I should jump up a jet size. The thing is, it runs really good and strong on top. The way its explained, your supposed to start with mains and work your way down. Also the needle is on the 4th clip I would think would be on the rich side. That doesn't seem to be the case. My instinct is to go up a jet size, but I'm looking for some other opinions. I've talked with a few guys that actually went down a jet size with my similar set up and elevation. I priced an innovate A/f today. $195 from a local dealer. might be next on the list.

 

[06VMAXIMUS]

Are you sure you don't have an intake leak somewhere? Your settings sound pretty good to me...

 

[tothemax93]

All the rubber boots are new. Carb and vboost. All the plugs read exactly the same. I Would think that if I had a leak, a difference would show up on one the plugs. I can double check it though.

 

[adambweird]

Maybe up a jet size and shim the needle to 3.5.

 

[06VMAXIMUS]

New boots kinda rule out an air leak! When you say it is ruff between 2 and 4K, is it at steady throttle or accelerating? I would be interested to see what happens if you take the ties off the slide springs and run them stock? Pretty easy to do, and won't require tearing too deep into the carbs.

 

[sdt354]

Make sure the carbs. are fully seated. I've been burnt by that one. I'd move the needle clip one step toward the pointed end and do another plug read. 3 1/2 is fine.
Steve

 

[tugla]

post a pic of your plug might help.

 

[tothemax93]

New boots kinda rule out an air leak! When you say it is ruff between 2 and 4K, is it at steady throttle or accelerating? I would be interested to see what happens if you take the ties off the slide springs and run them stock? Pretty easy to do, and won't require tearing too deep into the carbs.

It was running ruff at a steady cruise between 2-4. I can take ties off the springs. I was only playing around with them anyway.

 

[[email protected]]

Steady cruise in that range would most likely be the needles. I'd try raising them with a shim and see if it helps. You want to keep the needles as lean as you can while maintaining smooth response.

If it helps a little but not enough, jump up a whole clip.

 

[tothemax93]

post a pic of your plug might help.

 

[tugla]

is that from a wide open cut then pic taken or you been idling first.

id go with what others said try the spring without ties. and either a shim on four or id drop the needle to three and try see It might get better. then fine tune with shim.

 

[Traumahawk]

If I remember right, people have had good luck using the stock springs, instead of stage 7..etc.

 

[tothemax93]

is that from a wide open cut then pic taken or you been idling first.

id go with what others said try the spring without ties. and either a shim on four or id drop the needle to three and try see It might get better. then fine tune with shim.

Pic is from just normal riding. Went for a twenty minute pulled into garage and shut it off. No plug chop of any kind.

 

[tothemax93]

Quick question about needle adjustment. The write ups talk about raising or lowering the needles. Using the blunt end of the needle as a base line. which direction would the clip go to make it richer or leaner. For example if I'm on the 3rd clip from the blunt end and I wanted to go richer. would I go to the 4th or 2nd clip.

 

[donnelly317]

4th clip from blunt end. Look at it as the more away from blunt end you go the more the needle is pulled away from jet... same as putting shim in (which is half the distance between notches ) put the shim in raises needle from jet creating richer results

Sent from my SCH-I535 using Tapatalk

 

[alorio1]

Make sure the air box is well seated and the Y on top of the air box is on.....

 

[tothemax93]

A little update. I had some time the other day so I started from scratch. I pulled the carbs off the bike. I reseated them, made sure of all the vent tubes were correct. All the boots were correct. After it was all together I checked all the connections with my little propane torch. I squeezed the trigger half way for the gas to come out, but not to light. Did this all around the carb boots and no revving up, so all was good. The plugs showed lean, just the same as before. I started testing needle positions. I went through all the clip positions going up, and 2 going down. My goal was just to test and see which position had the very best driveability. I settled on the 3 1/2 clip. Didn't make any sense to go to a leaner position, but it was the best. The plugs are still showing lean. (3500 rpm plug chop) I'll play a little with the A/F next. One thing I did notice is that when I set the clip position to 3 and then ultimately 3 1/2 that I could hear the slides clatter considerably more at the lower RPM's (3000 to 4500), Than when the clip was set higher. 4th clip or above. Is that possible, or am I hearing things. I thought maybe that could also be a clue as to the proper setting on the carbs. Don't get me wrong, the bike runs strong. I am just looking to get the very most out of it.

 

[marsmax85]

It's also one of the best way's to learn about your bike ,,GOOD FOR YOU :clapping::clapping::clapping:

 

[dannymax]

Tim, do you think it would be worth doing a 4K - redline in 4th gear plug chop, just to verify the main is correct? Maybe a 165DJ would be better, it's just a smidge bigger than the 152.5 main according to VMax Outlaw's chart.

 

[sdt354]

If I remember right, people have had good luck using the stock springs, instead of stage 7..etc.

Ditto Eric, if you put them side by side there is a huge difference. I've had good luck tying three stock coils together with small tie wraps.