Dave told me the same thing when I had those issues. I have a '95 running k&n air filter, vance & hines, Dyna 3k Ignition module. I installed the 105 jets and one extra shim and ran with the stock filter for awhile. it was pretty good, definately better than origional setup. i added the k&n and then the trouble started. the k&n/vance &hines allows it to flow better, thus leaner. as soon as i put the old filter in, the midrange stumble got better.
i played around with various setups, and finially found a combo that works great for me. i have tried 105,108,110 and finally 112 jets. i upped the pilot two sizes from stock 40 to 42, then to 45. and i am using 3 shims on each needle, and the d screws are at 3 turns out, but it's just a tad rich at idle, i need to back them down to 2.5 or 2.75 turns out. if you need part numbers (acutal kehin/honda parts) letme know and i'll shoot them back to ya. One thing to check before you get crazy into this is to make sure you took out the two rubber o-rings on either side of the air filter box. if these are still in while putting the k&n back, there will be an air leak as the lid would not seal properly to the bottom half. hope this helps. -chad
I'm still trying to get my 96 magna sorted out, and I'm stuck again. I installed Dave Dodge's jet/shim kit along with Vance&Hines pipes and K&N filter. Before
this, the bike ran OK except for the usual stumble around 4k that most stock bikes seem to have. Now, under throttle, the bike goes great, but at light throttle it runs rough and pops both decel and accel. I called Dave Dodge and he said it's a vacuum leak somewhere. I removed and reinstalled carbs making sure everything was tight, and still have the same issue.
Could a small air leak in the airbox cause this much rough running? Also, there
is one hose near the hose that connects to the back of the airbox that is not
connected to anything. It comes off one of the tubes that runs between the carbs. I can't find anywhere that it could go. Maybe just some kind of breather hose?
Any ideas of probable vacuum leak areas would be appreciated. Thanks.