Misfire

[edgarjessop12]

Hi, I have posted this problem on my 2018 Tracer 900 GT before, but have had no joy.

The bike very slightly hunts at only fixed throttle, as soon as you accelerate or ride fast 8000 revs plus perfect.

It is worse at low revs 3000 revs in 1st and second gears and 4000 revs in 3rd and 5000 revs in the higher gears

only when cruising at a fixed speed. Fitted new plugs and Air filter, just so annoying. I have had the bike 3 years 

and done 14000 miles. It has been a brilliant bike, until now. So took it to a Yamaha Main Dealer they had it for a 

hour and road tested it as well, result Nothing wrong , yes it does have a slight misfire now and again, but MOST

Tracer 900 GT's suffer just the same. We could spend hour's on it and still find no fault. 

I know it is a fueling problem, so the only answer I think is to junk the standard exhaust and fit a sports exhaust

then get the E.C.U. set up on a Dyno Rolling Road. But at 76 years old, and on my 39th bike I want to just ride now

my days of spannering are coming to a end. And being retired for 10 years I only have a pension. 

So it looks like bye bye Tracer and back to Honda's

Sorry about moaning just wanted to get this off my chest.

Cheers Edgar Jessop.   

[KrustyKush]

My 2021GT will “misfire” from time to time but only at idle. It seems to “miss a beat” here and there. I don’t usually pay much attention to what any engine is doing at idle since idle isn’t what I bought it to do. I can’t say what other Tracers act like ‘cause mine is the only one I’ve encountered so far. I do believe the occasional unloaded missed beat is normal.

As far as rpm “hunting” goes, my 2021 absolutely does not do this. However, like a couple other bikes I’ve owned, especially my 2014 FJR, as the bike moves over road undulations my throttle hand will also move. This will cause small throttle variations. A rider may not be aware of the throttle pipe movements they are so tiny. Is it possible that this is the cause of the OP’s rpm hunting at cruise speed?

 

[Skidood]

I bet if you run some Sea Foam thru it, it will help.

[Grumpy Goat]

3 hours ago, edgarjessop12 said:

Hi, I have posted this problem on my 2018 Tracer 900 GT before, but have had no joy.

...

I noticed no mention of throttle body synchronization having been performed (or not). This, according to my user manual, needs to be done every 4000 miles. 🙄  Was this ever done on your bike?

[Skidood]

2 hours ago, Grumpy Goat said:

I noticed no mention of throttle body synchronization having been performed (or not). This, according to my user manual, needs to be done every 4000 miles. 🙄  Was this ever done on your bike?

Being an electronics-ey guy, I'd be more suspicious of a bad TPS at the grip, only because  I can't see how TB sync would have anything to do with the fluctuations in RPM at steady throttle.

[Skidood]

OP's post going to be subject to lots of different responses, since "hunting" and "misfire"  are kinda sorta 2 different things.

[Ride365]

TB sync, and install one of these......and Honda's are not immune to running issues either.  

 

https://www.boosterplug.com/shop/boosterplug-yamaha-mt-09-569p.html

Edited May 5, 2022 by Ride365

[edgarjessop12]

On 5/4/2022 at 6:09 PM, Grumpy Goat said:

I noticed no mention of throttle body synchronization having been performed (or not). This, according to my user manual, needs to be done every 4000 miles. 🙄  Was this ever done on your bike?

Cheers Grumpy, But yes I have already had this synchronization done.

[edgarjessop12]

On 5/4/2022 at 8:43 PM, Skidood said:

OP's post going to be subject to lots of different responses, since "hunting" and "misfire"  are kinda sorta 2 different things.

I was a old school mechanic for 25 years and have had 39 bikes. without being rude to the Yamaha Main dealer Workshop

Manager, he is wrong the hunting is definitely a FUEL problem. I know nothing about modern electronics, but to me it is the 

ECU that is the problem, ditch the catalytic exhaust, and fit a sports exhaust and get the ECU flashed or remapped.

 

[edgarjessop12]

On 5/5/2022 at 2:22 PM, Ride365 said:

TB sync, and install one of these......and Honda's are not immune to running issues either.  

 

https://www.boosterplug.com/shop/boosterplug-yamaha-mt-09-569p.html

Cheers Ride365, That sounds interesting. Will get in touch with booster plug. Although I am sure it is a fuel problem that

is making the bike hunt, but worth a look thank you. Was going to take off the catalytic standard exhaust, fit a sports 

exhaust and get the ECU flashed or remapped.????

[Wintersdark]

On 5/6/2022 at 11:50 AM, edgarjessop12 said:

Cheers Ride365, That sounds interesting. Will get in touch with booster plug. Although I am sure it is a fuel problem that

is making the bike hunt, but worth a look thank you. Was going to take off the catalytic standard exhaust, fit a sports 

exhaust and get the ECU flashed or remapped.????

The booster plug adjusts the fueling, when at low rpm and under heavy acceleration when the bike is in open loop mode.  

It tells the ECU the air temp is 10 degrees lower than it is, causing the ECU to enrichen the mixture whenever it's using the fuel map to adjust fueling (vs. steady state cruising where it's using the O2 sensor).  This SIGNFICANTLY improves low speed throttle, and throttle response under hard acceleration.  

Flashing the ECU goes further, of course, and is more effective overall, but for most use cases IMHO the booster plug is great.  I ran one for quite a while and really loved it - only removed it as I'm replacing the exhaust this year, and flashing, because I want a pretty new exhaust more than anything else.  

While the booster plug does make a big difference when you first rip open the throttle (though no appreciable difference afterwards) the improvement to low speed/low rpm riding is outstanding.  Very substantial.  

And it's comparatively very cheap ($150usd shipped, IIRC) very non-invasive to install/remove.  

 

[Cogswell]

On 5/4/2022 at 9:11 AM, edgarjessop12 said:

Hi, I have posted this problem on my 2018 Tracer 900 GT before, but have had no joy.

The bike very slightly hunts at only fixed throttle, as soon as you accelerate or ride fast 8000 revs plus perfect.

It is worse at low revs 3000 revs in 1st and second gears and 4000 revs in 3rd and 5000 revs in the higher gears

only when cruising at a fixed speed. Fitted new plugs and Air filter, just so annoying. I have had the bike 3 years 

and done 14000 miles. It has been a brilliant bike, until now. So took it to a Yamaha Main Dealer they had it for a 

hour and road tested it as well, result Nothing wrong , yes it does have a slight misfire now and again, but MOST

Tracer 900 GT's suffer just the same. We could spend hour's on it and still find no fault. 

I know it is a fueling problem, so the only answer I think is to junk the standard exhaust and fit a sports exhaust

then get the E.C.U. set up on a Dyno Rolling Road. But at 76 years old, and on my 39th bike I want to just ride now

my days of spannering are coming to a end. And being retired for 10 years I only have a pension. 

So it looks like bye bye Tracer and back to Honda's

Sorry about moaning just wanted to get this off my chest.

Cheers Edgar Jessop.   

Which ride mode are you in ?  Does it do the same thing in all three ride modes ?

[Grumpy Goat]

9 hours ago, Wintersdark said:

The booster plug adjusts the fueling, when at low rpm and under heavy acceleration when the bike is in open loop mode.  

It tells the ECU the air temp is 10 degrees lower than it is, causing the ECU to enrichen the mixture whenever it's using the fuel map to adjust fueling (vs. steady state cruising where it's using the O2 sensor).  This SIGNFICANTLY improves low speed throttle, and throttle response under hard acceleration.  

...

And it's comparatively very cheap ($150usd shipped, IIRC) very non-invasive to install/remove.  

 

What is the effect of the booster plug on fuel economy? I would expect that since the mixture is enriched (more gas is used) the consumption is increased.

[Wintersdark]

47 minutes ago, Grumpy Goat said:

What is the effect of the booster plug on fuel economy? I would expect that since the mixture is enriched (more gas is used) the consumption is increased.

Nothing measurable.  The changes only happen in open loop mode: low speed low rpm and hard acceleration.  

At low speed/low rpm you're using very little fuel so a bit more doesn't matter, and you're not spending much time under hard acceleration.  

Because when it's in closed loop mode using the O2 sensor, it doesn't use the air temperature calculation anymore and instead adjusts based on the O2 sensor result.  

So you do use a little more fuel, but it doesn't impact cruising fuel use and that's where the lion's share of your consumption comes from.  There was no change to my overall average fuel usage before/after according to the dash display or my overall range. 

You'd only really notice if you took it to a track or where riding stop light to stop light doing hard pulls at each light (guilty, occasionally) at which point you'd use up to 8% more fuel.

Obviously don't use it with a flashed ecu as that will already run richer, so it'll compound the result. 

[Ride365]

Just wanted to give my impression so far on the booster plug I installed Friday. Took a 130 mile spirted ride yesterday, and I am left pretty damn impressed overall. It idles better, low speed running is more smooth and not as jerky, more instant acceleration when on the boil, and the biggest change.......the on/off abrupt throttle transition is all but gone. Engine is simply so much smoother overall and I even believe that some vibes are a bit reduced, hell I even feel the quick-shifter is smoother.