Hesitation/Rough Idle Problem

[mattvt15]

Hi All,

Just bought a 2007 FZ6 a few weeks ago and the bike ran great....until the other day. Was out riding for 5-10 minutes and was stopped at a light. As I start to go, the bike hesitated for what seemed like 10 seconds (even though I'm sure it was only a second or two), then it took off. I was down to 1 bar of fuel so I thought I was running out of gas, rode to the nearest station and filled up. However, this was not it, it continued to hesitated every time from a stop, and sometimes as soon as I shifted into 2nd gear and let off the clutch. At a stop, the idle was also bouncing around. I was an auto mechanic for 6 years and it almost felt like a miss, but it wasn't consistent.

I've searched the forums and read all about the TPS issues, ran the diagnostics and it read 16 closed and 100 WOT, which is on the money. So I'd like to think its not that. The guy I bought the bike from said he had a similar issue before (can't remember how long ago), and the dealer tried a lot, but finally determined there was carbon build up. It sounds like this could be the same problem, no?

If so, what is causing it? My guess is that it is running rich, but I'm not 100% sure. The only mod the bike has are Leo Vince SBK exhaust. Could the exhaust be the problem? The previous owner did not remap it.

Any feedback would be much appreciated as I don't want to damage the bike and would like to get this resolved before it happens again.

-Matt

 

[RJ2112]

My first guess would be something that passes through the bike, as it comes and goes and leaves no identifiable signature...... bad fuel? If you ran it right down to the blinking light, it's near the bottom of the tank -- whatever sludge may have built up in there would then get sent through the motor.

Try running some injection cleaner through it for a couple of tanks, and see if it improves.

 

[TownsendsFJR1300]

When checking the TPS did you check to see the numbers go up without skipping/jumping and back down, again without any skipping?

If the TPS is good, try some chevron techtron, it works very good at cleaning the fuel system. Seafoam also works well at cleaning the fuel system and helping to remove carbon from the combustion chamber.... Both are cheap enough and won't hurt anything...

You didn't mention how many miles on the bike, when/if was the intake system sync'ed?

I have Scorpions on my 07 with the cat and didn't re-map (stock ecu), no problems, runs very strong. I don't know about the Leo's but the Scorp's are about staright thru....

 

[deeptekkie]

There are others far smarter than I on this board but in my own personal experience I would first look at the fuel. Once an idiot truck driver put his load of diesel into the regular grade gasoline tank at a local station. (Naturally my tank was nearly empty so I bought a full tank of the vial mix!) When my van would run, it ran exactly as you describe here. Just a thought. Good luck!

 

[mattvt15]

It could be bad fuel, but I doubt it because I ran it 100+ miles. When I filled back up again, I used the top stuff, 91 octane I think.

I did watch the TPS values up and down and there wasn't any skipping of numbers, it all looked good. I bought some Seafoam yesterday and added it to the tank. I let it run for 10 minutes but couldn't ride it as it just snowed up here!! (at the end of April!!!!).

The bike has about 8400 miles on it currently. As for the intake sync, i don't believe it has ever been done. Is this something that has to be done? How does it help?

I'd like to think it was just bad fuel (and maybe I just only put regular in it the first time.....it was just after I bought it, so my mind was more on how awesome this bike was then paying attention to the gas I bought). I'm a little worried of just riding it with the new gas and Seafoam as I don't want to damage the pistons or anything because of it running badly.

But seeing as the previous owner already had a problem like this before, I feel there must be some other underlying problem that hasn't been discovered.

 

[TownsendsFJR1300]

I run regular fuel and don't have a problem with it.

The throttle sync should be done however unless its out alot, it doesn't sound like your problem. An out of sync engine tends to vibrate more at lower RPM's, just not run strong.

Your symptoms sound fuel related.

Chevron Tectron also makes an excellent fuel system cleaner (as does Seafoam). I use both on occassion in all my machines as well as an additive for ethenol.

Hope this helps...

 

[Mancolt]

Chevron Tectron also makes an excellent fuel system cleaner (as does Seafoam). I use both on occassion in all my machines as well as an additive for ethenol.

Where can you pick either of these up? I'd just like to keep some on hand. And do you add some to each tank when you fill up, or do you do it every couple of fill-ups? Is the additive for ethanol a separate product for the Chevron Tectron and Seafoam or is it already added in to them?

Thanks!

 

[Sparky10]

I am far from a mechanic, but my old ninja 250 was acting very similar last summer. I ran a can of fuel system cleaner (conklin 4-power) through it and the tank of gas that I treated seemed to run better. But as soon as I filled it up again, it would sometimes dies at idle and would hesitate when starting from a stop.

I took my tank off and dumped ALL the gas out of it, and then refilled it. That fixed the problem. I think some water had just gotten in my gas tank. You may want to try that next time you are close to empty if running some fuel system cleaner through it doesn't help.

 

[RJ2112]

I am far from a mechanic, but my old ninja 250 was acting very similar last summer. I ran a can of fuel system cleaner (conklin 4-power) through it and the tank of gas that I treated seemed to run better. But as soon as I filled it up again, it would sometimes dies at idle and would hesitate when starting from a stop.

I took my tank off and dumped ALL the gas out of it, and then refilled it. That fixed the problem. I think some water had just gotten in my gas tank. You may want to try that next time you are close to empty if running some fuel system cleaner through it doesn't help.

Gas line drier will also help with this sort of thing..... it's mainly Isopropyl alcohol, which chemically binds with the water in the tank. doesn't magically make it disappear, but it does give it some degree of flammability.

At least that way, when it gets sucked through the injectors, there's something that will burn in the cylinder...

I like the idea of dumping the contents altogether.

 

[TownsendsFJR1300]

I agree, I would dump the tank altogether and blow it out with air making sure
all the gas/water is out. Seafoam and tectron are sold at most automotive stores, I get both at Walmart.

I fill several 5 gallon containers at a time and mix all my additives at one time. Keeps me from guessing on how much to put in.

The Tectron basically (per the bottle) cleans the combustion chamber, fuel systems, fuel injectors, etc.

The Seafoam does basically the same as the tectron except that its a fuel stabilizer, dries fuel and oil.

Neither products address (not noted at least) the problems with ethanol (fuel separation/break down. Fuel now adays breaks down in as quickly as a month).

What I've found and have been using for that is a product called "Gas-Shok". "It is a water absorber and fuel stabilizer. It dramatically reduces phase separation in ethanol fuels". I found this at the local marina as it was highly recommended. My Yamaha 4 stroke 150 HP outboard sips fuel, literally, and the 50 gallon gas tank will allow fuel to go stale quickly. The Gas-Shok alleviates this. Its not cheap however 1 oz treats 10 gallons for normal use. 2 oz for 10 gallons for marine use. The marina I frequent carries it, I would think most marina's would either carry it or a variant of it.

As stated earlier, I mix up fuel in 5 gallon containers and mix it exactly however adding more won't hurt anything....

 

[champion221elite]

I like Seafoam, or Stabil Marine formula. Both products stabilize fuel, clean injectors and carbon from engine components.

Stabil Marine goes one step further and prevents a condition called Phase Separation that can happen with Ethanol laced fuel. Ethanol is hydroscopic and will absorb water much in the same way as brake fluid will.

Once the Ethanol molecules are saturated with water, they will separate from the gasoline and settle to the bottom of your fuel tank. Once this happens, your motor will be sucking straight Ethanol/water instead of gasoline since most fuel pickup lines are at the bottom of your tank.

I use Stabil Marine in every gallon of fuel that gets burned in my Mercury 225 EFI outboard. Water and 2 stroke engines are a VERY bad combination.

 

[mattvt15]

Hey guys, been away from a computer for a little bit, but wanted to thank you for your help.

Weather up here in VT finally turned nice and I was able to get some miles with Seafoam in the fuel tank. I think between that, and riding her like your supposed to once in a while (not shifting until at least 10k once in a while) helped clean her out. She is back to running great!

Thanks for all your help

-Matt