Hey all
So this is going to be a bit of a read, but I'm going to be as in depth while keeping it to the point as I can.
TL;DR: Bike will not accelerate, idles and free revs fine, fires up first kick or so, but under load and past 1/4 throttle acts as tho there is a rev limiter. Have tried multiple approaches to diagnosing problem which range from playing with jetting to swapping parts from a known good bike, and have had very little success
Now before we start, here is the bike and mods/repairs done
96 Banshee
Fresh top and bottom end with all new seals/gaskets, stock bore/stroke, head milled and new jug MX style ported by HJR, welded crank, compression at the moment cold was around 120, which seems very low for a fresh motor with porting/head work, however I haven't even been able to break the motor in, so that may have something to do with it
Jetting WAS set at 330 main, 27.5 pilot and #3 on the needle as per recommendation of Kevin at HJR, temp ATM is 60-75 degrees with elevation at 1200 ft above sea level (Phoenix AZ) I will dive into this below as part of my diag
Running AVGAS with Lucas semi synthetic at 32:1
Toomey T5s
K&N style pod filters with outerwares (at the moment not installed for diag)
Brand new V force 4 Reeds, some generic boost bottle I had lying around (figure'd it couldnt hurt, unless it has a hole in it causing all my problems, then It will become a shooting practice target)
NGK B8ES gapped to .025, stator/flywheel pick up set at .018
No TORS, No parking brake, none of that, I went through the wiring harness to check for problems/continuity and remove all the BS that goes alone with that, there is nothing related to that on this bike aside from a bare, parking brake-less clutch perch.
Timing plate advanced +4
Bike has LED lights on it, two spots and a small bar on the bash guard wired into the stock wiring, no rectifier/battery, etc. I cant see how that would affect anything due to the lighting circuit being separate of the ign circuit, just adding to give as much info as I can
Stock other wise
Ok, so, now onto what I've (attempted) to do to try and figure out this problem. My friend lent me his great running 98 to swap parts from, which is similar to my bike mod wise minus the port/head work, his jetting is 290 on main, 27.5 pilot, and #3 on the needle, just for a base reference, I will refer to this bike as the "Swap Bike". Also, I did all this in steps to try and rule out any issue, I did not swap/change/adjust all at once, just to clarify
Carbs are spotless clean, choke tube is in place between them, synced properly via "peep hole" on side of carb, slides properly installed with angled/swept edge oriented towards rear of bike
Tried riding around with choke popped out on first setting, bike ran worse, so my thinking is too rich on the main. Pulled the plugs just to see, plugs were soaked. I played with the jetting and needle position and leaned the main all the way down to a 280, which is less then the swap bike had in it, it seemed to climb the RPM range a bit better, but still hit that wall and would not accelerate properly/spit sputter etc. Also swapped sliders/needles from swap bike, as my needles looked aftermarket (different color/strange part number then swap bike), no change there. The swap bike had 380 mains in it when we first picked it up years ago, aside from fouling up the plugs and not liking the higher elevations up north, it still screamed like a banshee should, which made me question the jetting on mine
Tested and swapped 3 different stators, and 2 different flywheels, as well as putting timing back to 0, no change
My coil was new, but tested and swapped anyways, no change
I had a Dyna FS CDI kicking around, tried swapping that, no change
Reeds are new, but inspected anyways/checked if installed right, no problem found
Checked and cleaned ground point for harness, as frame was painted recently for strip down, as well as previously stated inspected/cleaned/rewired/tested/ and removed unnecessary tors/parking brake wiring from harness, no change, even added a ground point from head bolt to ign coil bolt, no change
Inspected toomeys for possible clog, no problem found
kicked bike over with plugs out to see if possible coolant leak internally (had an issue with the head leaking first time around putting motor together, turned out to be a bad gasket), no problem found
Kicked bike over with plugs out and installed in caps, have nice blue spark
Im sure I'm forgetting more I've done, but I have searched multiple forums/threads, and checked off as much "common sense" stuff as I could find, with no success
This bike is racking my brains guys, Ive never had a machine give me such a head ache, and I work on VWs for a living! Please, any help would be great, I don't want to, but I'm getting to the point where I'm going to take it to my local bike shop, and as a mechanic, that is about as low as it gets for me
Thanks
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