Had the thundermax for about 3 weeks and just put 6600 mile trip from NC to california and back.Ran great no problems and even maintained 40 mpg with every kind of weather and 10% ethanol.
Problem seems to have come about on last part of trip and when getting home.Under hard acceration it stumbles bad from 60 to 70 in 5th when running wot ,after 70 it starts to pull strong a gain and necer quits pulling but the stumble seems to be in fuel delivery.Im thinking maybe lil more fuel right here might help,problem is no tach yet and not shure about rpm,thinking it 2700 to 3100 range.If you know rpm for this speed range for 2006 roadking custom with factory gearing Id appreciate knowing it.If other Ideas to problem that be great too.
Oh yea its 95 ci,11:1.anderws 59g cams,1.90/1.60 valves and ported heads,thunder header and thunder max with auto tune.It ran li8ke bat out of hell till this problem and it been fun busting some bigger inch motors *** but this could limit the fun.Like i said any ideas as to source of stumble would be great

 

Don't know the RPMs for a RK but for my Sporty 3K is about 65MPH.

If the stumble has just started, I'd be looking at an exhaust leak or intake leak. It could be trying hard to autotune to the new leak and can't make the changes fast enough. Just a thought....and my only one....sorry I'm not anymore help.....

 

Not sure it would be the tmax causing it if it just happened after running well for so long. Generally the cause would be too much accel fuel going in, and not lean. In basic module settings drop the accel fuel a couple of points and try it again. Rule out any possible mechanical issues first, like intake and exhaust leak. The intake will make it lean, and a leak in the exhaust will fool the O2 sensors and add more fuel to the engine. Milage will drop if this is the case as the engine will be running too rich. While linked up, do the afr checks on the O2s to see if you get the 19.36 reading on both to varify they are ok. Good luck.
Ron

 

about 3000 rpm at 70 mph.