Besides coughing or backfiring (which mine does NOT do) what would a lean condition sound like? Bike starts and runs great. But I notice on decel a bit of a stumble, especially at higher RPMs. I have a K&N filter and Supertrapp pipes, so she's wide open. I did not rejet when I put those on. Thoughts?

 

It would not accelerate freely if too lean and would feel like you were being held back

 

I keep saying I need to rebuild the carb, just haven't had the time yet. Have all the parts. Brand new petcock, fuel line and Super E rebuild kit. Just seems to stumble a bit on decel, and even high RPM slow cruising thru town and such. Also seems that 1st and 2nd gear run out of oomph way too soon. Winding out and no power. It doesn't build any real power until I get on it in 3rd gear.

Was running with a few buddies over last weekend. One of them was on a '88 or '89 Tour Glide. Basically the same motor, only he had a stock carb. Him and other guy were hot ******* it off the line as I followed. I couldn't have kept up with them if I tried. Leads me to believe I have an issue. Until now I had nothing to compare it to as no one else I know has an EVO. I am now wondering if I have enough gas getting to both jugs?

Ignition cover is still riveted so that is stock an unmolested.

 

Want to get around your buddies?
Andrews 3 or Wood 6.
Re-surface .060" from heads(or better yet a Wiseco piston) with a GOOD valve job, and have it tuned.
They'll think there is something wrong with their engines.
Scott

 

I do plan on an EV13 cam install next year. Funds are tight at the moment. Not sure how much further I will take it.

Think I am going to try and get a sound clip of what mine sounds like when its acting out and stumbling. Maybe then someone with a good ear can say for sure what they think my issue is.

I did have some issues last year with my carb. Cleaned it all up and readjusted everything then, haven't touched it since. I am fairly certain this is all carb related, just don't have much experience with it, yet!

 

Air/idle screw should settle in at/near, 1 1/2 turns out if the pilot jet is right, with a comfortable idle at about 1000 rpms at full operating temps.
Set the accel pump 3 turns out from bottom, for starters.
Scott

 

Your Super E has a larger throat ID than stock and should get more air through the motor. You said it is not coughing and I don't read that it is backfiring so you must be close. Just curious, what color is the chrome on your head pipes? Gold is lean and blue is rich, I prefer blue over gold.

It takes time to do this without a dyno and O2 sense but it was done that way for years so it can be done. Just be patient and document your opinions for each jet change. All the fuel goes through the main jet 1st. If you don't get the main jet right the rest hardly matters. I would pull the bowl and remove your main jet, right down the jet size stamped then purchase a couple jets above and below that baseline. When you get your new jets, install the next bigger, tune and ride it. You will know when you went too big when it starts backfiring through the exhaust at WOT. You can do the same going smaller and when you get too lean it will start sneezing or coughing through the air cleaner.

 

From S&S
http://www.sscycle.com/files/7913/70...stallation.pdf

High Speed (Main) Jetting Procedure:
1- Drag strip/dynamometer procedure
a- Sufficiently warm engine to begin testing.
b- Make run noting engine rpm and final speed or horsepower.
c- Richen main jet by increasing jet size .004" and make second run. Again, note rpm and final speed or horsepower.
d- Continue procedure until mph/horsepower falls off.
e- Decrease or lean main jet size by .002" to gain best rpm and mph. When making runs on drag strip, strive for consistent miles per
hour, not lowest ET.
2- Street Procedure - S&S uses "rpm" method to determine main jet size. Under racing conditions this level is where horsepower peaks
and begins to taper off and is where gear shifts occur. Main jet that makes engine accelerate strongest or rpm through gears quickest
is correct.
NOTE: Placing engine under load by accelerating uphill may make result of jet change more pronounced and easier to interpret.
a- Warm engine to operating temperature.
b- Accelerate rapidly through gears noting how quickly and smoothly engine reaches rpm level where pull of engine begins to fade
and gear shift occurs.
c- If engine backfires in carburetor and sputters or "breaks up"and/or dies during acceleration, increase or richen main jet size .004"
larger and road test again. Note engine smoothness and how easily engine reaches rpm where gear shift occurs.
Picture 43
21
d- If engine runs flat and sluggish or "blubbers" or will not take throttle, decrease or lean main jet size .004" smaller and road test
again. Note engine smoothness and how easily engine reaches rpm where gear shift occurs.
e- Continue changing main jets until jet which makes engine accelerate or rpm through gears quickest and smoothest is identified.
S&S'sŪ experience is that jetting about .006" smaller (leaner) than correct will make engine break up and quit. Jetting about .006"
larger (richer) will make engine blubber and miss.

 

http://www.sscycle.com/files/2113/58...uningGuide.pdf

 

Thanks guys! This is the feedback I was looking for. I have all those docs in hand already.

To start with I have a set of Supertrapp SE pipes and True Duals I put on last year, along with a new K&N filter this year. I did not rejet when I put the pipes on. Honestly not sure what jets are even in there. I can only assume they have what should be the stock jets that carb came with. That I need to verify yet.

Symptoms I notice are:

1) 90% of the time I need to pull the enrichener when starting. otherwise I get what I call a sneeze out of the carb if I just try to start without the enrichener pulled. That's one reason I think it's running lean. Always pops right off with the enrichener pulled, and no sneeze. After its warmed up idles settles in at 950-1000 RPM's.
2) No backfiring or coughing when running, only that sneeze at start sometimes.
3) Seems to run out of power quickly 1st and 2nd gears. Comfortable shifting 3000 RPM's and above. When I hit 3rd it then start pulling in some power. No misfire or stumble under acceleration (that's the issue I had last year). Just seems to stumble like it's out of time at high RPM's when slow cruising thru town and such. Hard to run at 25mph as 2nd gear seems too low and 3rd gear seems too high.
4) I don't hear other bikes doing this. Has to be carb related IMO. Thinking I don't have even flow to both jugs.

Getting ready to do a few things to it, as it needs a rear tire right now and will not be getting a lot of miles until she gets new shoes. So 1st order of business will be the new Pringel petcock, new fuel line from that to carb, and a full carb rebuild. Will verify jets at that time (or might drop the bowl now before I do the rebuild to check jets). Any suggestions or recommendations as to jet size for my set up?

Haven't noticed the coloring on the head pipes, will check that too. I should also check the plugs too, I have a new set of wires and plugs for it I believe.