Vibration/pulsing at 50 - 55 MPH in 6th

[Thomasec]

Dave you are definitely one of the best voices of reason on here and I almost always agree with your opinions. However this "problem" is real and I am guessing you are not experiencing it. I only wish you were closer so that I could let you try mine. Might change your thinking.

 

[Thomasec]

Greg, I would recommend you try yours at 55-65 mph in 6th just to see. It won't hurt it. (BTW - It feels unlike anything else I've ever felt. Very strange.)

 

[Beemerphile]

Dave you are definitely one of the best voices of reason on here and I almost always agree with your opinions. However this "problem" is real and I am guessing you are not experiencing it. I only wish you were closer so that I could let you try mine. Might change your thinking.

I wish I could ride one with the "problem". Not own one with the problem, just ride one to see if I could figure it out. I may try to ride the othe one that my dealer has when I go in for my freebie chain.

 

[Beemerphile]

Dave you are definitely one of the best voices of reason on here and I almost always agree with your opinions. However this "problem" is real and I am guessing you are not experiencing it. I only wish you were closer so that I could let you try mine. Might change your thinking.

I wish I could ride one with the "problem". Not own one with the problem, just ride one to see if I could figure it out. I may try to ride the other one that my dealer has when I go in for my freebie chain.

 

[mike5100]

I wish I could ride one with the "problem". Not own one with the problem, just ride one to see if I could figure it out. I may try to ride the other one that my dealer has when I go in for my freebie chain.

Sorry for posting without introducing myself but I HAVE ridden a bike with the problem whilst my own does not have it. While my NC700X was in for its first service the dealer let me take out their identical demonstrator (I wanted to see what mpg I got on it). I noticed the pulsing straightaway - and didn't like it. To me it proves they don't have to do it, and it's got nothing to do with the way the rider rides the bike. Both bikes were/are the DCT
Mike
PS - I got the same 'crap' mpg on both bikes so I guess that is down to me

 

[Little Ed]

Beemerphile- I just broke 2000 miles on my bike, and it appears that the pulsation has actually worsened some. It is now being felt in 4th gear and appears to be a bit worse in 5th and 6th gear. Possibly I am just being being ultra sensitive to the problem. ( I clearly feel this is a problem) Anyway, I believe earlier that you mentioned that you also had the same pulsastion. If so, have you noticed any difference over time/mileage?

I am planning to pull my plugs again to check them for buildup and would also like to check the compression this time. (At about 800 miles they looked the same). One question I have---> when running the compression test, should I pull the fuel pump fuse and start the engine to relieve the fuel pressure prior to pulling my plugs for the compression test. My concern is having the two injectors pumping fuel into the cylinder while checking the compression? My hopes are to determine if there is any noticable difference between the two cylinders possibly leading to valve adjustments, etc.

 

[mike5100]

On another bike forum, one of the cures for a vibration problem is to slacken off all the engine bolts and retighten them to the correct torque - in a particular order.
Mike

 

[mike5100]

Beemerphile- I just broke 2000 miles on my bike, and it appears that the pulsation has actually worsened some. It is now being felt in 4th gear and appears to be a bit worse in 5th and 6th gear. Possibly I am just being being ultra sensitive to the problem. ( I clearly feel this is a problem) Anyway, I believe earlier that you mentioned that you also had the same pulsastion. If so, have you noticed any difference over time/mileage?

I am planning to pull my plugs again to check them for buildup and would also like to check the compression this time. (At about 800 miles they looked the same). One question I have---> when running the compression test, should I pull the fuel pump fuse and start the engine to relieve the fuel pressure prior to pulling my plugs for the compression test. My concern is having the two injectors pumping fuel into the cylinder while checking the compression? My hopes are to determine if there is any noticable difference between the two cylinders possibly leading to valve adjustments, etc.

Ed - since it was apparent on a demo bike with zero miles on the clock, it's very unlikely that it could be anything to do with the plugs
Mike

 

[duk2n]

On another bike forum, one of the cures for a vibration problem is to slacken off all the engine bolts and retighten them to the correct torque - in a particular order.
Mike

Please, give us more info about this

 

[mike5100]

Please, give us more info about this

Well the forum I'm talking about is the Triumph Rocket 3 owners. It's a big lump of an engine and according to the service manual, the engine bolts (4 or 6 I can't remember) have to be tightened in a particular order and (obviously) to the correct torque. If this ain't done it's known to cause vibration problems - though I can't say anyone has reported a pulsing problem.
Mike

 

[Beemerphile]

Beemerphile- ... Anyway, I believe earlier that you mentioned that you also had the same pulsastion. If so, have you noticed any difference over time/mileage?

No, believing Thomasec that anyone who has it, knows it, I'd say I do not have it.

I am planning to pull my plugs again to check them for buildup and would also like to check the compression this time. (At about 800 miles they looked the same). One question I have---> when running the compression test, should I pull the fuel pump fuse and start the engine to relieve the fuel pressure prior to pulling my plugs for the compression test. My concern is having the two injectors pumping fuel into the cylinder while checking the compression? My hopes are to determine if there is any noticable difference between the two cylinders possibly leading to valve adjustments, etc.

That is the normal way to do it, but the NC does not have a separate fuse for the fuel pump. You would need to unplug the fuel pump. It is a black 2-wire plug located on the left side of the bike on the side of the metal bracket that holds the front mount for the front seat. You would have to remove the left lower cowl to access it. The test should be done on a warmed up engine with both plugs removed.

 

[670cc]

Greg, I would recommend you try yours at 55-65 mph in 6th just to see. It won't hurt it. (BTW - It feels unlike anything else I've ever felt. Very strange.)

Thomasec,
On my manual NC700X in sixth gear: At 2000 RPM, the engine is a little thumpy and pulls weakly but does not vibrate abnormally. When the RPM hits around 2500, the mild thumping gets rougher. Midway between 2500 and 3000 RPM there is also a throbbing, pulsation component (about a 1.5 Hz frequency) that appears mildly, although with my ear plugs I can't hear it so much as feel it a little. This seems to have improved with bike age. As I near 3000 RPM and an indicated 55 MPH the engine begins to smooth out again. At 3100 RPM and above it smooths out and purrs. Does that also describe your bike?

I keep my RPMs as low as possible to maximize MPG. My current average is 78.6 MPG(US), about the best on Fuelly. I ride it in this 2000-3000 RPM range only when I'm rolling with no load just for economy's sake. Otherwise I just ride in fifth gear until I hit 56-58 MPH and the bike is smooth. The area where I ride requires constant shifting and speed changes due to the nature of the roads and what I feel like doing at the time, but speeds average about 50 mph.

Greg

 

[duk2n]

Well the forum I'm talking about is the Triumph Rocket 3 owners. It's a big lump of an engine and according to the service manual, the engine bolts (4 or 6 I can't remember) have to be tightened in a particular order and (obviously) to the correct torque. If this ain't done it's known to cause vibration problems - though I can't say anyone has reported a pulsing problem.
Mike

Well, this could be a track to follow...

I didn't have any vibration nor pulse issue, but since I fitted my Givi crash bars (use 4 of the engine mounting bolts) I'm noticing some vibration at around 70mph. I'm pretty sure the bolts are at the correct torque (double checked), but I didn't follow any particular order.

@Beemerphile, if you're reading this, you also fitted the Givi bars, did you noticed something similar to what I'm describing? Did you follow any particular order when tightening the engine bolts?

 

[mike5100]

Thomasec,
On my manual NC700X in sixth gear: At 2000 RPM, the engine is a little thumpy and pulls weakly but does not vibrate abnormally. When the RPM hits around 2500, the mild thumping gets rougher. Midway between 2500 and 3000 RPM there is also a throbbing, pulsation component (about a 1.5 Hz frequency) that appears mildly, although with my ear plugs I can't hear it so much as feel it a little. This seems to have improved with bike age. As I near 3000 RPM and an indicated 55 MPH the engine begins to smooth out again. At 3100 RPM and above it smooths out and purrs. Does that also describe your bike?

I keep my RPMs as low as possible to maximize MPG. My current average is 78.6 MPG(US), about the best on Fuelly. I ride it in this 2000-3000 RPM range only when I'm rolling with no load just for economy's sake. Otherwise I just ride in fifth gear until I hit 56-58 MPH and the bike is smooth. The area where I ride requires constant shifting and speed changes due to the nature of the roads and what I feel like doing at the time, but speeds average about 50 mph.

Greg

Greg - do you ever ride at 70-80mph which seems mandatory on UK main dual carriageways if you don't want to get trampled over?
Mike

 

[Beemerphile]

@Beemerphile, if you're reading this, you also fitted the Givi bars, did you noticed something similar to what I'm describing? Did you follow any particular order when tightening the engine bolts?

No I didn't notice anything.I torqued the top first and then the bottom. I do it in three increments (even thirds) instead of just one. I don't know how much, if any, it matters. Are you sure it was not the aerodynamic effect that you felt? I am making some fairings for the front of mine out of impact modified acrylic sheet.

 

[670cc]

Greg - do you ever ride at 70-80mph which seems mandatory on UK main dual carriageways if you don't want to get trampled over?
Mike

Very rarely. I assume you mean what we might call the "Interstate", the "Superslab", or technically, "a divided multi-lane limited access highway." I ride my NC strictly for pleasure, not really to get anywhere, so I avoid those types of roads. I ride a short spell at 75 MPH just to open her up, but it's only 3% of my riding on that bike. If I need to ride big highways to actually get somewhere I take the Goldwing 1800.

Are you asking because of fuel economy concerns? Lower speeds is likely the main reason for my decent mileage numbers. That seems to be true of most any vehicle.

 

[Little Ed]

Mike- I agree. I don't suspect the plugs being bad however if there is any inefficiency in the combustion of one of the pistons, for whatever reason, it might be evident with some carbon deposits, etc on the combustion surface of the plug itself (quick and easy check). The compression test should indicate any valve issues

 

[mike5100]

Mike- I agree. I don't suspect the plugs being bad however if there is any inefficiency in the combustion of one of the pistons, for whatever reason, it might be evident with some carbon deposits, etc on the combustion surface of the plug itself (quick and easy check). The compression test should indicate any valve issues

I hadn't realised that the plugs were so accessible. On a Rocket or Versys, lots of stuff has to come off to get at the plugs. Can you use an ordinary compression tester, and just take off the HT leads and crank the starter?
Mike

 

[mike5100]

Very rarely. I assume you mean what we might call the "Interstate", the "Superslab", or technically, "a divided multi-lane limited access highway." I ride my NC strictly for pleasure, not really to get anywhere, so I avoid those types of roads. I ride a short spell at 75 MPH just to open her up, but it's only 3% of my riding on that bike. If I need to ride big highways to actually get somewhere I take the Goldwing 1800.

Are you asking because of fuel economy concerns? Lower speeds is likely the main reason for my decent mileage numbers. That seems to be true of most any vehicle.

Yes but there seems to be lots of people over here claiming to ride at 'normal motorway speeds' who are getting 80mpg UK when I am getting 67. I got better figures round Scotland last week (75mpg) and top speed on those roads was about 60-65. Didn't seem to matter whether I put it in S or D mode
Mike

 

[gkgeiger]

Without going back and re-reading this thread, has anyone reported this to their dealer and had their dealer report it to Honda? I'm just wondering if Honda is aware?