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

Yamaha FJR Motorcycle Forum

Help Support Yamaha FJR Motorcycle Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
If heavy rain is the issue, please let us know.
Please let us all know.

As I mentioned in my prior post, I checked the error codes that night when I arrived at my accommodation.

There were none, and like yourself was somewhat concerned by the event.

I did find a few similar cases on other bike forums a few weeks later.

I've ridden through a lot of rain events and nothing similar has ever happened.

Be interesting to hear what Yamaha's tool will tell you.
additional items to state would be, I had washed my bike by the car washing shop, they used jet spray to wash my bike. after that, i did rest awhile as it was raining after the wash, when i set off, it was normal, then a heavy rain pour, and i got that issue. update you all on sat evening.
What can happen is pooled water somewhere inside can be evaporated by engine heat, the vapour spreads everywhere and condenses anywhere you don't want it to, like around spark plugs.
Personally, I'd never let anyone else jetwash my bike, if they put too much water pressure near wheel bearings, the water can get through the seals. Electrical connectors are also vulnerable. I have jet washed my own on occasion, but I am careful where I use a lot of pressure. Car-wash personnel are unlikely to take that care.

 
Last edited by a moderator:
The tech told me is due to my TCS activation. Hence I am experiencing the jerking feeling. Hmmmm....

 
The tech told me is due to my TCS activation. Hence I am experiencing the jerking feeling. Hmmmm....
I'd call total BS. Unless you are on an extremely slippery road, there's no way the TCS would operate under low-rpm (as you apparently were) conditions. The only time I've known mine happen is under hard acceleration, typically overtaking and going over a wet tar snake in the road, I feel the back end step out a bit then it recovers, I barely notice any power change - probably because I'm already reducing power at the same time as the TCS is operating.

If it was damp on your plugs, I don't think the ECU would notice the problem, after all, the spark is still happening, just not where it should be. The only thing it might pick up on is the exhaust gas oxygen sensor that would probably give unusual signals, but whether it would flag this as an error code or merely seek to adjust the air-fuel ratio, who knows?

 
I am quite disappointed with them. I thought they will do a 100% check, but no. Gosh... they are supposed to be the best person to know about the bikes of Yamaha!!!

 
Well, the fact that you let someone pressure wash your bike changes the whole deal. As stated above, NEVER let someone near your bike with a pressure washer. My bet is they forced water into something that should not have been wet. I've ridden my '07 in thousands of miles of rain, and never a stumble. Freaking out after being pressure washed doesn't surprise me.

Most likely, if you never do that again, you'll never have that problem again.

 
The FJR ECU is a fairly crude device compared to automotive ECUs. For instance, it does not have any adaptive ability to "learn" how the bike runs. It just runs off of the real time sensors and static look up tables.

I know that the 2016 models now have OBD2 compliant interfaces, but I suspect they still do not store anything that doesn't result in a check engine code.

As for riding through heavy rain, I did that in the first months of ownership with no problems, and many times since. How about heavy snow? Just did that today in Vermont while trying to get over the mountains to Rutland for a tag. Bad idea and I turned around, but the bike ran flawlessly. :thumbsup:

 
Cool79,

Can you make a video with audio in first gear, say maneuvering in a parking lot?

Even someone else doing the recording.. That would be a big help...

My old 04 FJR and current FZ6, I can easily let the clutch out at idle (slowly) and both would / will pull easily W/O

bucking/jerking. It'll idle in gear (flat ground), as long as you ask it to, and that engine doesn't have nearly the torque of the FJR..

 
Cool79,
Can you make a video with audio in first gear, say maneuvering in a parking lot?

Even someone else doing the recording.. That would be a big help...

My old 04 FJR and current FZ6, I can easily let the clutch out at idle (slowly) and both would / will pull easily W/O

bucking/jerking. It'll idle in gear (flat ground), as long as you ask it to, and that engine doesn't have nearly the torque of the FJR..
I only got it once. Now it is fine. I had also done another wash and it's fine till now. Just installed the Yamaha slider on my bike yesterday by the agent and they exposed the wire out.

I just dismantle the side fairing and put the wire back in. Woh.... it's a lot of job!!! and I realised that I only need to dismantle just the internal black panel and job was done! Damn!!! Now I got a quick connector stuck within my bike and I do not know where it is. Got to go back to the agent to buy the quick connector and get them to check if I have installed back the fairing correctly a not.

 
damn, today i rode in the heavy rain and it happened again! I had brought it back to the agent and made him to test the bike in the rain and he did experience lost of power. I had placed my bike with them again. As I would be going overseas for holiday, I hope they will really do a full test and check what has happened. This time, I had not pressure jet wash my bike.

 
tested out in med to small rain, bike is ok after the side stand sensor replacement. yet to try in heavy rain. Will test it when there is a heavy rain pour.

 
damn... it's still the same, does all the gen 4 got this issue? one of my friend who is riding gen 4 also face this issue!!!

 
How does the bike operate when you ride it normally: with rpm at 3k or above? Maybe you should just stop lugging it. It wasn't designed to run at such a low rpm.

 
How does the bike operate when you ride it normally: with rpm at 3k or above? Maybe you should just stop lugging it. It wasn't designed to run at such a low rpm.
Come on, Fred, if it runs differently when wet than when dry, then there is something wrong.
I totally disagree that "It wasn't designed to run at such a low rpm". The FJR will pull smoothly and without distress from tick-over if you want it to. Wet or dry. As I've stated more than once, running under 3000 rpm is not necessarily "lugging".

All three I've had would run very happily below 3000, in fact about town that is certainly their "normal" running, and none were any different in the wet. Also, all have survived proper Scottish all-day downpours with no difference in performance. Me, yes (picture a drowned rat), but not the FJR. Very often on my Gen 2 bikes I would deliberately use low rpm because of the lack of traction control under wet slippery conditions, that is still my habit with my Gen 3.

Now, my pre-FJR Trophy really didn't like the rain, until all the plug leads were replaced. I think it was made with left-over Lucas leads.

 
My old 04 FJR, on level ground, would idle in first gear with me on board at 1100, no problem.

My current FZ6 the same, 1100 RPM, no chugging, etc... And that's with much less torque down below (14K red line)

 
normal dry condition, i am also riding ard 3000rpm. more than that will be above the speed limit and burning more petrol.

regardless dry or wet, it should be running smooth even below rpm 3000.

 
How does the bike operate when you ride it normally: with rpm at 3k or above? Maybe you should just stop lugging it. It wasn't designed to run at such a low rpm.
Come on, Fred, if it runs differently when wet than when dry, then there is something wrong.
I totally disagree that "It wasn't designed to run at such a low rpm". The FJR will pull smoothly and without distress from tick-over if you want it to. Wet or dry. As I've stated more than once, running under 3000 rpm is not necessarily "lugging".

All three I've had would run very happily below 3000, in fact about town that is certainly their "normal" running, and none were any different in the wet. Also, all have survived proper Scottish all-day downpours with no difference in performance. Me, yes (picture a drowned rat), but not the FJR. Very often on my Gen 2 bikes I would deliberately use low rpm because of the lack of traction control under wet slippery conditions, that is still my habit with my Gen 3.

Now, my pre-FJR Trophy really didn't like the rain, until all the plug leads were replaced. I think it was made with left-over Lucas leads.
mine is a new bike, possible that the plug lead is faulty? It just hit 2,000 km.

 
...
mine is a new bike, possible that the plug lead is faulty? It just hit 2,000 km.
The leads I was referring to are the high tension ones going between the ignition coil and the plug. Your bike doesn't have them, the coil is directly over the plug (often referred to as "COP", Coil Over Plug). It is normally the plug circuit that is most vulnerable to moisture, if your problem is in that area then it might be a bad coil or whatever sealing there is between it and the cylinder head (I've not seen mine, so I can't be specific). If not there, it could be in any of the ignition wiring leading to the coils.
I suppose it could even be water somehow being sucked into the cylinder(s), but if that was possible I'd expect other symptoms of poor running even in the dry. Missing air filter allowing water from the air intakes?

 
...
mine is a new bike, possible that the plug lead is faulty? It just hit 2,000 km.
The leads I was referring to are the high tension ones going between the ignition coil and the plug. Your bike doesn't have them, the coil is directly over the plug (often referred to as "COP", Coil Over Plug). It is normally the plug circuit that is most vulnerable to moisture, if your problem is in that area then it might be a bad coil or whatever sealing there is between it and the cylinder head (I've not seen mine, so I can't be specific). If not there, it could be in any of the ignition wiring leading to the coils.
I suppose it could even be water somehow being sucked into the cylinder(s), but if that was possible I'd expect other symptoms of poor running even in the dry. Missing air filter allowing water from the air intakes?
checked on the air filter, everything is in placed. only the plug area, I didn't open up and check. let's see tomorrow after they have installed the logging system on my bike and see what would be the outcome. hopefully that would pick up the issue, as currently, here is a raining season for these few months.

 

Latest posts

Top