Power stutter at 45 - 50 MPH

Edbo1960

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Hey everyone, I have a 2014 ES, about 8,000 miles, reflashed with Yoshi. No issues after reflash just started to stutter/stumble around 45 50 MPH in Tour or Sport mode in mainly 4th gear. I bought bike last winter, I run premium gas or non-ethanol don't believe it ever had plugs or carb synch - any ideas?? Thanks, Edbo
 

Jlq1969

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Hey everyone, I have a 2014 ES, about 8,000 miles, reflashed with Yoshi. No issues after reflash just started to stutter/stumble around 45 50 MPH in Tour or Sport mode in mainly 4th gear. I bought bike last winter, I run premium gas or non-ethanol don't believe it ever had plugs or carb synch - any ideas?? Thanks, Edbo
It would have to be discarded from minor to major. Start with the spark plugs. the Synch carb is only for idling
 

EricV

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At 8k miles, you would not normally need spark plugs. Water in the plug well from washing or riding is possible, as Fennellg mentions. Unless someone was pulling on things or moving things around aggressively when doing the flash or removing the ECU, it seems unlikely that the plug wires would have damage.

What's the last thing you did to the bike?

Have you ever checked the air filter?

Has the problem persisted thru more than one tank of gas?

Do you always get gas at the same place?

Air, Fuel, Spark. These are the three things that make our engines run. So your problem is likely related to only one of those.

I would check the air filter and make sure the vent lines to the tank are not crimped and correctly tucked into their retaining clips down low after you are done. (you need to lift the tank and remove 11 screws as I recall. One is hidden under a rubber plug in the center of the air box lid) Use a strap or bungie cord to hold the tank up while you work. You need to pull the two vent lines loose down low in front from the retaining clips so the tank can move up. Just loosen the pivot bolt at the back of the tank, no need to remove it. The other two bolts, one at each side can be accessed by removing the right lower panel and just a few of the upper bolts on the left so you can pull it out and get a wrench in there. It's not necessary to remove the entire left lower panel.

There is a drain in the air box. Check that for oil and clean it out. It has a clear cap over the drain that can be removed from the outside.

If the air filter looks fine, while you are at it would be the time to check the spark plugs. That requires removal of the air box base as well. There are some obvious bolts and a breather hose in the middle under the air box. The breather hose has a hose clamp. Long needle nose pliers work well for that. It's a little fun getting it back on later. :) Pull the breather hose up a bit to help.

Answer the questions and if you feel comfortable, take a look at the air filter and plugs. It may be as simple as bad gas.
 

WJBertrand

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The Tenere has no spark plug wires, at least on the secondary side, since the coils connect directly to the plugs. First thing I would check is to make sure the ECU connectors are fully seated. Maybe one wasn't fully engaged with its retaining clip when the ECU was reinstalled and has started to work loose?
 

Edbo1960

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Thanks for all your help! To answer some questions, I get gas at different places, haven't washed or driven in rain,no major or minor work done recently. I think my next step is to check air filter and plugs....stayed tune.

PS: came over from a FJR, the fueling on that was spot on.....but don't miss the weight.
 

Farbar

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Oct 2, 2017
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Check out the Jumpy Throttle thread. I had the same issue. Replaced TPS with a new one from alibaba for $50 and all is well again.
I think running around the same speed a lot of times , or on cruise around same speeds creates a resistance spot in the TPS and whenever your bike decells or accelerates accross that spot, it can hiccup. TPS is just a fine scale potentiometer. I also changed my accelerator sensor while I was in there (reads the input from your wrist) as that can cause the symptom too. You can spend some time in diagnostics 1 and 14 to check the readings, VERY slowly moving from closed to WOT. Any jumpy or missed numbers, is highly suspect. Plus you get to see the initial settings. 1 should be between 10-20 (15) and 14 should be between 12-22 (17) Rotating them on their mounting screws adjusts the numbers
 

Just Bob

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I had exactly the same thing happen on my latest trip, thought I had gotten some bad gas. tried STP first, helped for about the first 12 miles, then went back to what you described. Then went with Engine Medic from Yamaha, cleared it up after about a thirty miles, it even runs smoother at higher speeds. Other members here have talked about Carbon build up on valves from running lower RPM,s. whatever it does, it sure made a difference. It says on the bottle that it cleans Injectors and carbon build up, figured I would start cheap then work my way up. But all cured. I have had other members recommend an oil change after the first hundred miles running this, dealer and bottle though say to run this all the time ????? Carbon removed has to go somewhere, would rather not have that crap in my oil case. So did oil change just to be safe. Just anecdotal info....grin.
 

Don in Lodi

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I had exactly the same thing happen on my latest trip, thought I had gotten some bad gas. tried STP first, helped for about the first 12 miles, then went back to what you described. Then went with Engine Medic from Yamaha, cleared it up after about a thirty miles, it even runs smoother at higher speeds. Other members here have talked about Carbon build up on valves from running lower RPM,s. whatever it does, it sure made a difference. It says on the bottle that it cleans Injectors and carbon build up, figured I would start cheap then work my way up. But all cured. I have had other members recommend an oil change after the first hundred miles running this, dealer and bottle though say to run this all the time ????? Carbon removed has to go somewhere, would rather not have that crap in my oil case. So did oil change just to be safe. Just anecdotal info....grin.
That's great news Bob.
 

Sierra1

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I'm with Bob. Clean, and then change the oil. No sense leaving it in there.
 

EricV

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I scoped my intake valves at 50k miles. Looked like they had asphalt poured on them. Still runs fine.
Not uncommon for a Super Ten. I was running Yamaha Ring Free in the gas on a regular basis, which helps build up. Need to do that a bit again. SeaFoam and Marvel Mystery oil also have positive effects on build up.

My first S10, when torn down at 83k for repairs had a lot of carbon. I had been running exclusively Rotella full synthetic on that bike, so decided to run only moto oil on the second S10 to see if it made any different over the long term. No clue yet. Really like the Motul synth I put in last time. Mail order thru Walmart, but I've often used what ever I could find at the auto parts store for moto oil in full synth.
 
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