[warning: way too wordy. the tl;dr summary: replaced spark plug, added speedoDRD,
bike had major high rpm stutter about 10 miles later, but after stopping and turning back
seemed to run fine...any ideas???]
I've just about hit 10,000 miles on the WRR so thought I 'd do some service, and I'd recently
bought a speedoDRD because the 20% +/-high reading of the speedo/odometer were becoming
Drained and removed the tank--used ramz's "levitating fuel tank" method to hold it up while
removing the electrical and fuel connectors--
removed the coil/cap, and extracted the original spark plug. Yuck!
All kinds of corrosion on the hex sided portion and the cap was full of red dust, rusty powder
of some sort. Cleaned the cap with contact cleaner, dried it out carefully, used a small hose
on the end of my shop vac to vacuum out the recessed hole in the cylinder head.
Gapped the new plug, torqued it, and put some dielectric grease in the cap before pushing it
down onto the plug.
The manual also says to "apply silicone hydrate to the sealing point of the ignition coil, and
install the ignition coil..." Have no idea what silicone hydrate is, couldn't find it via google either,
so I didn't do what ever it is you're supposed to do and just made sure the coil was pressed firmly
into the cylinder head surface.
Put everything back together, installed the speedoDRD and went for a little ride this morning...and
now for the reason for the "little freakout."
About 10 miles into the ride I come to a nice uphill sort of expressway section that goes from 35mph
to 55 mph, so I whacked the throttle and as it climbed into high rpms...splut roar splut roar roar splut...
kind of like how it feels when you're just about out of gas and the fuel pump isn't getting enough fuel.
I backed off the throttle and everything seemed fine. Rolled on hard again and same freaky hesitation
again. I've got about 3.6 gallons of gas in the 3.7 g capacity tank. Damn. Then the high temp warning
light came on! I slowed down, the light went off, and for the next few miles my mind was racing with
the possible causes, debating whether this was a real problem or not, finally decided to pull over and
check a few things.
I pulled the fuel tank cap and it didn't seem to be in any pressure (thinking it could be a venting issue),
even blew into the vent hose, seemed OK. Decided to head back rather finish the rest of the ride I'd
First time the WRR had given my ANY reason not to just ride it.
On the way back I tried the whack the throttle game again, but couldn't get it to hesitate! I even took
the long way back via I-680 and it pulled right up to a GPS (and now speedo-corrected!!!) 70 mph with
no problems. I did take my earplugs out for the ride back because I thought I was hearing some odd
sounds, there does seem to be some different kind of fluttery noise as I whack the throttle, but that
could be part of the airbox flapper--everything there is still stock.
So, I'm thinking it could be
1. Some weird artifact of the speedoDRD.
nah, not very likely. Occam's razon and all that...
2. Something wrong with the cap/coil; maybe too overzealous with the dielectric grease, or cleaning,
or maybe a bad plug.
possible, I guess
3. Fuel pump issues, either an impending failure or simply the pump hadn't completely filled yet, or I
didn't get the vacuum line back correctly, or ???
I'm leaning towards this,
but I'm still freaked out a bit by the fact that it went away. It is hot,
probably about 90°F when I was riding and getting hotter by the minute so I wouldn't have expected a
fuel pump failure to go away in those conditions.
I do remember hearing an odd "squeal" from the pump when I first turned the key on after putting
everything back together...
Dang, I do get wordy, but if anyone has experienced and solved something like this I'd appreciate
hearing from you.