[Mpatera]

Hi all. Just traded my RT for LT. Putting on some miles, after tire pressures checked, oil changed, brakes bled and otherwise given her the once over. 2 things.

First, when cold and warming, I have a significant miss. Can go away or significantly diminish when at operating temperature. What should I look at besides the injectors, if anything?

Second, on concrete at 70 to 80 mph, I get a howl like a banshee from what seems like to front end. seems to go away or diminish on tarmac. More pronounced after 1/2 hour or so continuous riding 2 up. I assume the Metzlers are singing but should I look at other sources?

Thanks!

 

[Mpatera]

Should have clarified, the "miss fire" seems to go away under throttle. I sense a miss when at speed but off throttle, but that could be me overthinking this. Thanks.

 

[Voyager]

Hi all. Just traded my RT for LT. Putting on some miles, after tire pressures checked, oil changed, brakes bled and otherwise given her the once over. 2 things.

First, when cold and warming, I have a significant miss. Can go away or significantly diminish when at operating temperature. What should I look at besides the injectors, if anything?

Second, on concrete at 70 to 80 mph, I get a howl like a banshee from what seems like to front end. seems to go away or diminish on tarmac. More pronounced after 1/2 hour or so continuous riding 2 up. I assume the Metzlers are singing but should I look at other sources?

Thanks!

The miss fire could be many things. How many miles on the bike? Any idea when the spark plugs and O2 sensor were last changed? Could be a lean condition due to a bad O2 sensor or could be a vacuum leak as manifold vacuum is highest as closed throttle positions. Often a miss fire that disappears as the throttle is opened is due to a vacuum leak. I would first suspect a cracked crankcase vent manifold and then next suspect one of the rubber intakes isn’t attached to the throttle body correctly.

The howl is likely a cupped tire. Does the noise change when you lean into a corner? I have found that tire noise generally changes significantly with lean angle. If the noise does NOT change with lean angle, then I begin to suspect the source is a bearing or something other than tires.

 

[CaliCruiser]

M.
Can't say that I have an answwer to your first inquiry, and believe that someone with more information may jump in later. As for the second seeing that you specified that the road noise is noticed on "Concrete" would leave me to believe that this noise is coming from the tire tread and road surface, more specifically the tire and the drainage lines, it may be something else? I have noticed the some noise from my front wheel when on Concrete, seems to change based on surface treatment and speed.

 

[Mpatera]

The bike is an '06 with 78K on the clock. So not out of question that bearings are getting worn out. If I am correct in believing a bad bearing would grind and/or scream at low speeds as well, this isn't the first choice. No such feel/noise.

As far as the tires are concerned, sure seems like tire profile is the issue Really howls when I lean the bike on concrete. Tires are relatively new (2-3 years) with approx 5K on them. I understand the weight of the bike eats up the tires pretty quickly. Added to the mix is the bike has been mostly sitting the past 2 years. Through 1-3 Minnesota winters and summers. Tough on tires.

I will change the O2 sensor and sleuth according to Voyagers suggestions for the miss fire issue. I will post the results when I am through.

Thanks to you both, Voyager and Cali.

 

[jzeiler]

It is tire noise, by the time a rear bearing CAN be heard your oil seal will be destroyed and oil will be all over your wheel. My very first trip back in 2004 when I bought my new LT I had about 5 K on her and heard the howl in the corners and thought the worst but it was just tire noise. I now have over 116K on here and no rear drive issues.

 

[Mpatera]

Thanks for the vote of confidence jzeiler.

 

[Mpatera]

OK. Replaced the O2 sensor with some improvement. Went for the vacuum hoses. Light tug on first and last hoses, attached to manifold, and they came off. Easily. Some abrasion evident on #1 as well. Nothing else loose or evident. A cannisterectomy had been done. Fired her up and she purred. Thanks Voyager for the tips.

As an aside, the previous owner had apparently removed the O2 sensor and sanded down the probe. Inexpensive effort, I guess. Not sure that works, as plenty of soot accumulated inside the probe and its holes.

Thanks again to all who responded. Most helpful and encouraging.

 

[Voyager]

OK. Replaced the O2 sensor with some improvement. Went for the vacuum hoses. Light tug on first and last hoses, attached to manifold, and they came off. Easily. Some abrasion evident on #1 as well. Nothing else loose or evident. A cannisterectomy had been done. Fired her up and she purred. Thanks Voyager for the tips.

As an aside, the previous owner had apparently removed the O2 sensor and sanded down the probe. Inexpensive effort, I guess. Not sure that works, as plenty of soot accumulated inside the probe and its holes.

Thanks again to all who responded. Most helpful and encouraging.

Sanding the metal shield over the probe will do nothing beneficial unless there is so much carbon that the vent holes in the shield are plugged. And if the debris from sanding gets inside on the probe I am not sure what that would do, but it likely isn’t beneficial.