Very jerky on acceleration and deacceleration

[Simoncrp]

I have a problem with my bike being very jerky. I'm not sure if it's me or the bike! The main jerkiness occurs when i twist the throttle from the starting point or if i release the throttle completely, however softly i go on it. It's ok if i increase or decrease the acceleration as long as i am still giving it some gas. However if for example i brake and then come on the gas or release the throttle completely, it's very jerky, even if I'm gentle. This happens in any gear and at any rev.
I am still pre my 600 mile service. Any advice?

 

[robodene]

Looks like a trip to the dealer is due.

 

[Ralph]

Mine was a bit that way though yours sounds much worse, at the 600 mile service it's supposed to have
the throttle body synced and on mine they richened up the low speed running it as been fine since so
tell them the problem if they know what they are about they should fix it.

 

[Simoncrp]

Thanks for replies.
Another question. When accelerating in 3rd gear and above, if I accelerate hard from low revs (2500), the engine/bike vibrates softly till it hits approx. 3000/3500 revs. I assume this is normal and is the nature of the MT 07 engine?

 

[Noggie]

Mine was like that before the first service, my chain got pretty slack, and I guess they adjusted the throttle bodies and possibly the throttle cable.
After the first service it was like a different bike. Before the service I had some issues finding the gears too, especially 3rd, that also went away, I guess with the chain being tensioned up.

I did not worry about it and just ran it the first 1000km and took it in for the service, when I got the bike back it was fine.

You could try to tension up your chain, I did not bother as 600miles/1000km is not really that far.
If you have a proper shop do the service you should get back a transformed bike just like me.

 

[Ralph]

To accelerate hard at those revs is not really kind to this sort of engine especially until it's run in
let it rev a little more, but yes the engine as a 270% crank so it fires unevenly like a V twin,
and that's likely what you are feeling, do check the chain as the other poster said they tend to
go slack over the first 600 miles but don't need adjusting very often once it as been adjusted 2 or 3 times.
The 270% crank gives a very long legged low revving lade back feel to this engine even when revving hard.

 

[Yaminator]

Rusty Handlebars maybe..??

 

[ufukgy]

maybe causes loose chains tension... As my bike
my chain tension adjusted in 1000km maintenance and problem solved...
but there is still little bit (actually is not very little) jerkiness when i twist or release the throttle, especially slow ride and low rpm (maybe this is caused by the high torque )
therefore I have to use the clutch while slow and sharp cornering

 

[Simoncrp]

maybe causes loose chains tension... As my bike
my chain tension adjusted in 1000km maintenance and problem solved...
but there is still little bit (actually is not very little) jerkiness when i twist or release the throttle, especially slow ride and low rpm (maybe this is caused by the high torque )
therefore I have to use the clutch while slow and sharp cornering

Exactly what i need to do! But it shouldn't have to be like that. I test rode a Honda CBR650 and it was soooo smooth.
Anyway, we'll see what happens in 200 miles after my first service. Could be that my chain is loose.

 

[robodene]

I always go with the feel of the engine. If it does not like revs below 3000 (this bike, and the TDM of similar ilk) then I will drop down a gear.

 

[ufukgy]

Exactly what i need to do! But it shouldn't have to be like that. I test rode a Honda CBR650 and it was soooo smooth.
Anyway, we'll see what happens in 200 miles after my first service. Could be that my chain is loose.

Cbr be smooth is normal because this is four cylinder

LG-D855 cihazımdan Tapatalk kullanılarak gönderildi

 

[DJP]

...Another question. When accelerating in 3rd gear and above, if I accelerate hard from low revs (2500), the engine/bike vibrates softly till it hits approx. 3000/3500 revs. I assume this is normal and is the nature of the MT 07 engine?

Yeah, low rev lumpiness is normal for a twin. Use a lower gear.

As for the jerkiness, that's probably down to a slack throttle cable - it's easy to adjust just do a search on here.

 

[Noggie]

Like I said, run it to the first service, and see how it is when you get it back.
Im sure it's just a few run in kinks that needs to be ironed out on the first service.
If you still have issues after the service, then make a complaint.
As it sounds like you are using the bike ( unlike mine which is in winter storage), the first service should be right around the corner, so just ignore it for now, and see what it's like after the service.

Also, use a good shop, preferably a Yamaha one, and don't try to save money on it by going somewhere where they might just do an oil change and that's it. My first service was about £250, granted I'm in Norway and things are more expensive.
Make sure you go somewhere that will do everything on the service list ( found in the manual ).
If you get a proper service done hopefully you should get back a bike as smooth as a twin can be. I know I got a completely transformed bike back from my first service.

 

[Simoncrp]

Like I said, run it to the first service, and see how it is when you get it back.
Im sure it's just a few run in kinks that needs to be ironed out on the first service.
If you still have issues after the service, then make a complaint.
As it sounds like you are using the bike ( unlike mine which is in winter storage), the first service should be right around the corner, so just ignore it for now, and see what it's like after the service.

Also, use a good shop, preferably a Yamaha one, and don't try to save money on it by going somewhere where they might just do an oil change and that's it. My first service was about £250, granted I'm in Norway and things are more expensive.
Make sure you go somewhere that will do everything on the service list ( found in the manual ).
If you get a proper service done hopefully you should get back a bike as smooth as a twin can be. I know I got a completely transformed bike back from my first service.

Thanks. The dealer that sold me my bike is quite local to me so I intend to use them for the first service. I think they quoted about £120 or so. Will let you know how we get on....

 

[sdrio]

Seems almost everybody has experienced the slack chain before 1st service issue - and it is always resolved after it is adjusted, and quite a few have sporadic problems with gear selection in the first few hundred miles, and again that always seems to go away.

Haven't heard of the rough running though. A few bikes have had problems with the engine cutting out altogether (something like stalling, but not rider fault). Definitely one to take to the dealer.

Just out of curiosity, do you use standard or 'premium' fuel? The vibration you mentioned could be a bit of preignition, often caused by low octane fuel. Have you tried it with the V-power or whatever your local garage sells as performance fuel? (or vice versa, if you already use that).

This all sounds like stuff the dealer can address at first service, but for the time being, I'd suggest take it easy with the low-rev high gear pulling stuff, that's pretty much exactly what you're not supposed to do during your run in period.

This is my opinion, of course, there is a completely separate school of thought that says running in should be done by spanking the living daylights out of the engine for 100 miles, changing the oil then riding normally. Hmm.

 

[Simoncrp]

Sdrio, it's not so much a rough running. It's more a soft vibration or soft trembling when accelerating in the higher gears at about 2500 revs which i don't think is too low if it's straight after a gear change. I think it's just the nature of the engine rather than something to worry about. I use regular unleaded petrol.
I have had an issue with the gears getting stuck between 1st and 2nd and the gear selector showing a line. I just have to release the clutch slightly and it clicks in to place. A bit annoying!
I've only had the engine cut out once on me though.

 

[Ralph]

What you are feeling is definitely the engine firing pulses these bike are intended to rev a bit
they don't have great big heavy flywheels like big V twins, it does more harm than good especially
with a new engine as for the gears most new bikes are a bit sticky when new but make sure you
are fully realising the gear pedal so it can return to its mid position after every change.
Let it spin up a bit much kinder on the engine.

 

[bobh]

A lot of modern injected engines seem to be this way, probably to get through emission tests. I think the fewer the cylinders, the worse it is.

My MT-03 single is the worst offender I've come across. There are various simple mods available to solve it - basically they bypass the Lambda sensor and fool the ECU into thinking it's still there so it doesn't throw up an error.

But I've got round it by simply trailing a bit of back brake when doing slow turns e.g mini-roundabouts, so there's just a bit of gas on all the time. Doesn't seem to wear the pads out too quickly, fortunately.

That trick works on somewhat faster stuff as well, once you've practiced it. In fact, when pressing on, I've started to notice that the MT-07 doesn't have as much engine braking as I'd expect, compared to other twins of this size. Maybe Yamaha have done something in the mapping to cause this, but it can be a bit disconcerting if you're rolling off into an apex and it makes the bike run wide. So again, the back brake is your friend.