Is this a norm? Jerky at low RPM (1-2 rpm)

[cool79]

is this normal? Yesterday, there was a huge downpour and I was riding in the jam, I was traveling on a speed of 50kmh in gear 3 or 4, it's feel very jerky like there isn't any enough petrol pumping in.

After a while, I change to sport mode, it got slightly better, but I still feel the jerk.

is this normal? I am riding a new 2016 model for just 2 weeks. I used to ride a ST1100 and I didn't experience before.

 

[graler]

50 kmh is about 32 mph. I would be in higher rev 2nd or just into 3rd. I would think 4th gear would be very jerky - almost no throttle.

 

[cool79]

50 kmh is about 32 mph. I would be in higher rev 2nd or just into 3rd. I would think 4th gear would be very jerky - almost no throttle.

it's ard rpm 1.5 to 2. very very jerky. it shouldnt be this case right?

 

[Surly]

Could be throttle body sync. ???

Dropping a gear should also help.

 

[Donal]

For me 2500 RPM is just about minimum (in any gear).

2500 RPM in third gear equates to ~ 30 MPH (48 KPH).

This bike will do 90 MPH (140 KPH) in second gear so if it's lugging (jerky) drop a gear..............

 

[rbentnail]

50 kmh is about 32 mph. I would be in higher rev 2nd or just into 3rd. I would think 4th gear would be very jerky - almost no throttle.

it's ard rpm 1.5 to 2. very very jerky. it shouldnt be this case right?

You wouldn't think so but it is. 4th gear is too high. 3rd gear is barely manageable at 1.5-2 unless on flat streets with stable speed. Any acceleration or deceleration will feel jerky. Better to be in 2nd gear for traffic areas.

So to answer your original question-- yes, it is normal to be jerky as you describe.

 

[Surly]

I would like a throttle body sync to be done to be sure.

 

[cool79]

50 kmh is about 32 mph. I would be in higher rev 2nd or just into 3rd. I would think 4th gear would be very jerky - almost no throttle.

it's ard rpm 1.5 to 2. very very jerky. it shouldnt be this case right?

You wouldn't think so but it is. 4th gear is too high. 3rd gear is barely manageable at 1.5-2 unless on flat streets with stable speed. Any acceleration or deceleration will feel jerky. Better to be in 2nd gear for traffic areas.

So to answer your original question-- yes, it is normal to be jerky as you describe.

Thanks. mean the min rpm should be 2.5rpm? I think after my run in, I can increase the RPM

Finally I can wack the beast very soon!!!

I would like a throttle body sync to be done to be sure.

It's a brand new bike, is it possible to be out of sync? Will be sending to Yamaha next weekend for my 1st 1000km servicing. will get them to check.

 

[mcatrophy]

Don't believe it should be jerky. Mine will pull cleanly at 30 in 5th (don't have a 6th on my '14) so long as I don't try to accelerate significantly. The Gen 3 fuelling is a smooth as you want down to tickover.

Check for TBS, also make sure it's not just some bad fuel.

 

[cool79]

Don't believe it should be jerky. Mine will pull cleanly at 30 in 5th (don't have a 6th on my '14) so long as I don't try to accelerate significantly. The Gen 3 fuelling is a smooth as you want down to tickover.
Check for TBS, also make sure it's not just some bad fuel.

so in short, there is only 1 possible issue? which is the TBS? will get it checked this weekend. thanks

 

[Queensland Ken]

No

 

[mcatrophy]

QKen is right, there are many possible causes.

Questions to ask, is this the first time it has been jerky? Does it behave better in the dry after this wet session? Does it change with throttle setting - how hard the engine is pulling at a given speed?

The first thing I would check would be the battery connections.

 

[cool79]

QKen is right, there are many possible causes. Questions to ask, is this the first time it has been jerky? Does it behave better in the dry after this wet session? Does it change with throttle setting - how hard the engine is pulling at a given speed? The first thing I would check would be the battery connections.

This is the 1st time i felt it. But also my 1st time going through a jam for a period of time.

But there's a few time, when I was starting off to work from the car park, I was in gear 1 and 2, I did felt a bit of jerk, but after i had exited the car park, it rode normal.

my normal cruising speed was 90-110km on 6th gear, which i didn't feel any jerk.

 

[Queensland Ken]

The one and only time my 2006 played up was during & after riding through a HUGE mega thunder storm, downpour, many years ago.

It eventually came good but ran like crap for a few hours.

I put it down to the HV Corana effect (look it up) + the water caused high voltage shorting (High voltage discharging) on the plugs / leads.

In your cast the discharge would be the spark plug boots, being a COP.

Strewth the bike is under warranty , go the a stealer, and being a 2016 ya buggered trying to get the error codes or testing.

Maybe water on the ECU plug / socket, the coil over plugs are driven straight off the ECU, a very simple circuit.

 

[Fjr doc]

Am no expert, in fact a newborn to fjr, but just asking a doubt. Could it be the simple TC ? Is it that intrusive? After the downpour was the road all wet and stuff? Could that be the reason why it improved a bit with sport mod?

 

[Hotboot]

Why are you riding at 2500 rpm ? That is just off idle and there is no throttle control or air moving down there. Lower engine speed and higher gear selection will usually produce some driveline jumping. I do not think TB service will do much on an engine designed to run between 4 and 8000 RPM. I personally use second gear when it's wet and I'm in traffic, throttle control and engine braking for me.

 

[mcatrophy]

Whether or not 2500 is "too low" (which IMHO depends entirely on what the rider feels at the time), the bike shouldn't be jerky. The issue needs fixing. Depending on what it is, it could develop into something a lot worse.

 

[flyfisher]

Brand new bike? Less than 600 miles? Put fresh gas in and run the **** out of it....it's not even broken in yet...2cents....ff

 

[Fjr doc]

Just FYI saw couple more posts online regarding 2016 with issues post rain, some thing to do with air box cover / hole problems. I don't think I can't post link from the "other " forums here. Just search for it and see if it applies to yours