motor has no power - makes a hun-nun-nun sound at WOT.. like its missing?

[FstaRockr Burns]

Makes like a hun-nun-nun sound at full throttle, has half power, takes forever to plane.. ran great in march - now its just a dog, ive tried 3 stators (spares) and similar results.. could the trigger be retarding the firing on one cylinder? I did index the pistons and the trigger doesnt appear to be crossfiring, only lighting up one cyl at a time.. but it did look like the brown trigger wire (cyl 3) was firing btdc and the other 2 atdc - 6 degrees

All 3 plugs jump a half inch gap with blue arc, compression 139,139,137 - although cyl 3 (bottom) looks like it misses every now and then - also - will the 3 cylinders all fire at the same pointer mark for cyl one or will they fire at their own pie marks (120 degrees)?

Starts really easy.. New filter,plugs,fuel lines, pump tested fine, replaced all orings on quick connectors, batt new/charged..

All elec connections cleaned, earth, starter connections, all bolts greased and replaced..


also im not sure if the dva tests should be with wires connected or not connected (stator and trigger)?

when i tried doing the dva test with the motor idling, it cut out when i attached the pos to the blue wire on the switchbox - however when i try the same dva adapter on my battery i get a 12.9v reading indicating it is working?

went from running great like this:





to this - and its worse now:




its even worse now - any ideas? also - do i do dva tests with stator leads disconnected and while cranking?

 

[FstaRockr Burns]

for some reason cant edit first post- here is the motor running GREAT in March:

 

[FstaRockr Burns]

and this is a month later - its even worse now:

 

[faztbullet]

That's a ignition miss...try new plugs first,then switchbox

 

[FstaRockr Burns]

That's a ignition miss...try new plugs first,then switchbox

thanks - plugs are new, im picking upa new switch box in a few days.. seriously hoping its that! just about spent on patience on this thing!

Do i do stator DVA tests with yellow and red and blue disconnected while cranking?

 

[Ed-Mc]

Defintely sounds like ign, besides DVA testing, check your coils for cracks. Sometimes they get so bad you can hear them going 'snap' at idle. Most times you have to pull the coil out of its cover and peel the rubber back to check the body of the coil for cracks (or arcing marks).


If you have an inductive timing light, run without the cowling and check each spark plug for firing. You'll see any misfiring right away.

BTW the first video sounded really good, that's the way they're supposed to run!