If you roll off throttle and the bike picks up, then general thoughts would lend themselves to suspect the jetting would be too rich.
Also the 65T rear, is not doing anyone any favors, and by rights, that EV-27 cam wants about 9.8 compression to be truely effective.
Scott

 

I'm really confused now. I have read numerous articles on tuning keihn and mikuni carbs, and from what I gathered, when going at wot, letting it pull for a few seconds, and then letting off an 1/8, if it speeds up your lean, and if it slows down your rich.
I have a mikuni here that I could try on bike, although I'm afraid any more testing may have to wait until spring due to the weather here.
I am going to check compression when time permits or I could bite the bullet and get it on the dealership Dyno to tune.

 

remember, lean it screams, rich it sputters.
if you are wot and the engine sputters, so call it 4 cycling, it is a sign of being rich. you could do plug chops but remember, after the wot, engine is shut down and de-clutched or reading can change.
typically i like to do wot first as it is simple, then mid circuits and lastly idle.
if sputtering and the throttle is rolled back where the mix is leaned out, machine will smooth out. if it is lean then as you roll back, you will get to a point where it will start to accel, but if too lean , temps rise and possible damage.
did you check the accel pump??

 

Loss of power in top gear w/2 different carbs?
Symptoms of scissored crank? (loss of power in top gear) IDK?

 

I definitely mussed that it has a cam in it.. In a stock motor with a 27 cam, cranking pressures are pretty low. If you have a free flowing exhaust and a longer cam with overlap, you can get what I call "over exhausting" The exhaust flow is very slow at TDC since the exhaust flow is so good. When this happens the combustion chamber scavenges poorly which kills TQ. You mention stock head pipes and VnH slip-ons. If the VnH muffs are straight through you may be over exhausting. The 27 cam has 6 degrees later close 36 degrees of overlap and 13 degree earlier exhaust open compared to a stock 98 cam. All of these things can kill low to mid torque.

I would look at the mufflers to see if you can add a restriction. The common ways to increase exhaust velocity are to weld a washer to the of a bolt and hang it at exhaust tip or to add torque cones to the head pipes.

The rich / poor roll off is really bit inaccurate way to get the main jet size close at 65 mph in 5th gear the motor is only spinning at 2500 RPM on a 98 softail. These bikes are geared tall.. You are basically below the power band of the cam with the current pipes.

Also the rich/lean roll off is not that accurate. Sure there are a number of web sites that repeat the same method for setting jetting. I've personally found that after proper jetting is check or done on the dyno, the roll off test shows rich.

Scott's suggestion of increasing compression is another good way to pick up Torque in that RPM range. The compression ratio on a stock 80 ci evo is only about 8.3 to 1. At 2500 RPM it's hard to build cylinder pressure when the volume isn't squeezed hard.

How does the motor run at 65 in 4th? How does it run when you wind it up? I'd guess it scoots along pretty good. Try the roll off test in 3rd at 65 and you get a better idea as to how the main is jetted.

I'd probably mess with exhaust flow, and if that doesn't work install a 30 tooth tranny pulley, or go to a 24/37 primary if you don't want to get into the motor. 30 tooth pulley (or 68 / 70 tooth rear wheel) will mess with the speedo.. Primary change won't.

 

i run a 01 sport with a tad over 10:1 but dynamically probably in the 8:1 range(over-lap). i run retarded camming so my engine really does not come to life till the 4k range. to add to this, i run int'l gearing so at 60mph, i am turning 2500rpm.
now if i roll on, it will scoot along but if i yank on it, it will let me know quickly. on a long pass, it does well but a short pass, will need to drop a gear or two.
a dyno is not in everyone's budget but if you do enough chops, you can get it darn close even if the afr aren't perfect.
on my machine, i have to run on the rich side in order to over come the wot lean out. around town, lite chocolate but running 5k for 50 miles at 120 mph the plugs lighten to normal, even more so if i crank the rpms closer to 7.5 limiter. really need a bigger carb.

 

One would hole that your dynamic compression gets close too 10 to 1 at peak torque.. Hopefully the VEs are close to 100%..

Dyno's and running on them can be pricey fer sure. I've easily spent a few grand on tuning and checking with me doing the tuning and a guy running a dyno.. The thing is with doing only chops is that you really don't know and you can't see how the motor is pulls when the timing changes.. You an advance til it pings and back off but you don't know if you have too much timing and are dumping too much fuel. It's nice to have a sniffer/ recording device. Have done a lot of tuning that way also..

 

I have the original mufflers for this bike that I could put on to see if there is any difference in power. I also have a 98Fatboy that has the same EV 27 cam, stock ignition and same carb set up. Vh long shots. I am very happy with the way it performs, so with the Springer having the same components (except exhaust) and being a few pounds heavier, I find the power in 5th totally different between the two. Day off Friday, so will be checking tranny gearing. And yes, I did buy the bike used 7 years ago. And will do compression test. I do appreciate all the replys.

 

Here is the thing from what I can tell. You have 2 bikes that should have identical gearing and motor except for the exhaust. A 98 Springer and 98 fatboy. Bikes have the same frame and ignition. Before doing anything I try to check the timing on both to make sure they are the same.. Frames are the same so swap the pipes and see if the problem stays with the bike or the pipes. Check compression on both bikes running stays with the bike and not the pipes.

Bike should pull the same at 65 as weight makes less of a difference than frontal area. For instance if one has a windshield and the other not, the windshield will have significant drag requiring more torque.

 

Try 3 full turns out on your mixture screw. That was the spec from Dynojet, IIRC.