Put some miles on yesterday. Seems with the one O2 sensor hooked up I've moved the problem across the mixture curve a bit.

I did speak to a Tech guy as well.... He claims that they haven't had any problems like I mentioned. His advice:

1) put the other O2 sensor on
2) look for any leaks intake/exhaust
3) run a tank of premium through it
4) see if there is a third party ECM on the bike

Oneperfectrun,

Have you solved your sputtering issue yet?

It will be a while before I can get another O2 sensor... until then I'm wondering if this is bad for the bike.

After a 10 minute ride the idle is sounding like there's a miss. I'll have to check the plugs again. If one set has fouled this quickly, I'm not sure I should be riding this beast.

Alltime it's been so hot here the last couple of weeks I havnt much more than looked at my bike. I am gonna remove the ais the first chance I get and see what happens. It's not even unplugged right now. Will let you know if I ever figure out how to solve the problem.

Thanks One. Hope the heat breaks for you real soon.

While I do need to run through those things the service guy mentioned, I've been reading the RS Warrior forum and from what I can tell, there could be a number of things causing this. From one of the sensors to bad electrical connections.

Been running with one O2 sensor for the last two weeks. As expected the front plugs look great while the back (rear does not have the O2 sensor) look way too rich.

What I've noticed over this period of time as well is that if I hit the sputtering point, 4th gear 45 to 50 mph, the bike seems to react like one cyclinder is not running well and at idle it sounds like it.

So, another O2 sensor on the way. We'll see if that takes care of it.

Update.

Waiting for Cheap Cycle Parts to ship the O2 sensor (taking for ever) but in the meantime I've been running a tank of premium with some injector cleaner.

I have noticed during the tank of prem that the sputtering issue doesn't show up unless I do a slight decel - up a grade or I inadvertantly let the grip drop a bit. This only happens in 4th and 5th at different speeds although doing 80 I can't really tell with the wind noise. If I drop the throttle entirely and then roll on to constant speed after dropping a few mph, it doesn't come back until the next slight decel.

It's not the destination, it's the journey getting there. Am I right?

Took the bike for the strongest ride yet. 1/2 hour in stop & go then onto the slab for 1/2 hour of 85 mph, then main road @ 50 mph plus some stop & go for about 45 mins.

The sputtering stopped somewhere along the way. Not sure exactly when but I noticed it during the last leg running in the sweet spot; 4th gear, 45 to 50 mph. One thing though, maybe due to the engine temp, the sound of the bike was a bit different. More of a pop on each cyclinder fire versus a poump...

The only variables that were different here was I had just filled-up with regular after the tank of premium plus injector cleaner. I did make a half-hearted attempt to push the TPS connectors together because the more I ride this bike the more I think that's the problem.

Will document the next ride as I expect the sputtering will be back next time I hop on. One thing is for sure, once I put the other O2 sensor on (Cheap Cycle Parts is not a company I'll be doing business with again) I'm going to focus on that TPS.

As expected, the sputter was back. Following my hunch on the TPS I took the BAK off and found that the wires leading to the TPS were pinched against the top of the cylinder.

I've moved 'em and will see if that had something to do with the sputter. I'll let y'all know... if anyone cares

sounds like ya been thru it..keep us updated.. my only experience with a tps has been on a carbed bike and I'm guessing they are two completely different animals...........

No go... still experiencing the sputter.

I still think this is a TPS problem because it seems as though I can lessen it or stop it for a short period with the throttle.

Anyone know how to get in touch with Yamaha engineering so I can discuss this issue?