Bogging down at 2 - 2.5k

[Jacobien]

Heya!

I hate posting on engine issues, as it saddens me...

In the mornings, when it is cold [17 degrees C] the engine idles a bit below the idle setting when warm of 1,300RPM.

When I pull out and rev the bike to 2,000RPM it seems sluggish. As I ride it, it is fine, but as soon as I have to pull away from a Stop it feels slow to respond up to 2,500RPM and then flies off.

Even when the enigne is later at temp 80 degrees C, it still does not respond well when pulling from a stop.

What I have noticed is that when I gun it to above 8k, it feels fine afterwards and idles nicely at 1,300RPM and pulls from a stop nicely too.

Here's what I've done so far, with little effect:

1) New plugs
2) Fuel cleaner [ 2 tanks now already ]

Bike has 44,000km

Peace

 

[ChevyFazer]

Have you checked you air filter?

 

[Jacobien]

Well, I check the air filter once every 6 months and it is usually very clean. The problems I have are at low revs, where the air filter will have the least effect. The bike runs fine at higher RPMs where any air filter problems will be evident. (Due to higher air flow needed)

 

[greg]

maybe you need to rev it a bit more 2k is barely idle speed

 

[CanadianFZ6]

Are you using different fuel for your last fill up?

 

[Jacobien]

I do not ride it at 2,000RPM but for me to ride it at 8,000RPM I first need to pass 2,000RPM. During that "pass" it bogs down.

I have been using the same fuel since 2008. And I am on my 2nd tank now from a different vendor.

 

[04fizzer]

How do your plugs look?

I'd also think about running some GOOD injector cleaner through for a couple tanks.

 

[Jacobien]

I replaced the plugs last night as well as cleaned the connectors. Plug one had a filthy connector.

I have been runnning fuel/injector cleaner for 2 tanks now.

My 2nd guess was that my CO settings were too rich, but at 18 they are way below the norm for a set of Leo Vince cans.

My next guess is now moving towards valve clearances...

 

[FinalImpact]

If it changes all the time I might opt for checking all of the connections, plug-ins for corrosion. TPS and air pressure sensor come to the top for me. Also go into diagnostic mode and confirm the repeatability of the TPS. Snap the throttle closed and slow roll it closed to confirm the sensor reads the same value.
You might also check your throttle cables. A gummy cable or one thats too tight with no free play could cause strange idle issues.

If all of that checks out -
It's probably a good time for TB sync and confirm the idle is 1300 warm. Curious - is that regular or premium fuel?

Some fuel simple burns better than others and could easily lead to this condition. Don't hesitate to burn some higher grade fuel through it.

That all comes to mind based on what you've said thus far. . .

 

[ChevyFazer]

I replaced the plugs last night as well as cleaned the connectors. Plug one had a filthy connector.

I have been runnning fuel/injector cleaner for 2 tanks now.

My 2nd guess was that my CO settings were too rich, but at 18 they are way below the norm for a set of Leo Vince cans.

My next guess is now moving towards valve clearances...

I know the co settings are different on every bike, mine was -27 -13, I moved them up I think 13 points a piece, so I your at 18 you might be WAY to rich!!! Especially if you said one of the plugs were real nasty. Do you remember what the stock setting was?

 

[FinalImpact]

I replaced the plugs last night as well as cleaned the connectors. Plug one had a filthy connector.

I have been runnning fuel/injector cleaner for 2 tanks now.

My 2nd guess was that my CO settings were too rich, but at 18 they are way below the norm for a set of Leo Vince cans.

My next guess is now moving towards valve clearances...

What does this mean? (Plug one had a filthy connector) between the cap and the plug was corroded? What are you saying here? If it was misfiring from a bad connection and the connection is still bad, the most likely time to be noticed is just off idle under the loads of acceleration. If this connection compromised; the plug may not be firing = problem!!!! That would make the idle variable as described. . .

Not Likely >> next guess is now moving towards valve clearances. . .

 

[Jacobien]

I also thought that the Co may be rich, as the bike runs bad especially when cold - when the rich mixture will be at it's hardest to ignite. I actually bumped it up to 21 yesterday, just to see if it will make it worse...

Stock was C1=5 and C2=5, so I will revert to those settings for a bit.

 

[mellofelow]

Glad I've found this thread. You know, I'm having similar problem. Interestingly, I'm running Leo cans as well. I just had my valve serviced at 18k. Although the engine block seems to be smoother, the fuel system problem remained the same. I'm going to send the injectors off to Witch Hunter performance and see if that will resolve some issues.

WitchHunter Performance - Injector Cleaning & Flow Testing Services

 

[04fizzer]

Glad I've found this thread. You know, I'm having similar problem. Interestingly, I'm running Leo cans as well. I just had my valve serviced at 18k. Although the engine block seems to be smoother, the fuel system problem remained the same. I'm going to send the injectors off to Witch Hunter performance and see if that will resolve some issues.

WitchHunter Performance - Injector Cleaning & Flow Testing Services

Or you could try fresh gas and a couple tanks of sea foam first. Cheaper options first.

 

[ChevyFazer]

Or just bottle feed that baby and never worry about it bogging again!!!!

 

[mellofelow]

Or you could try fresh gas and a couple tanks of sea foam first. Cheaper options first.

I have already run a couple of tanks of Yamaha's Ring Free, which is much better product than Seafoam (MHO). Although it has improved some but the stubborn problem is still there. I have a sneaky feeling that I may have leaky injectors.

 

[Jacobien]

I found the problem. One of the HT leads (spark plug leads) is shorting on the frame. I waited till dark, then disconnected the headlights and covered up all other lights. Started the bike up and saw little flashes (sparks) from one of the HT leads.

So cylinder 4 is getting a weak spark, which leads to misfires. So that I may be of help to the next guy, here are the symptoms you may look for:

1) The bike idles lumpy
2) When hot (200+) the bike will be very choppy on the throttle
3) When cold and at idle, you will smell unburnt fuel from the pipes
4) When cold/warm and occasionally, the bike will bog down when trying to pull away slowly

I now have to buy new HT leads and possibly new ignition coils. One HT lead is $ 57 and a coil is $ 98.

Thanks for the advice guys, helped me narrow down the culprit.

Peace

 

[FinalImpact]

I found the problem. One of the HT leads (spark plug leads) is shorting on the frame. I waited till dark, then disconnected the headlights and covered up all other lights. Started the bike up and saw little flashes (sparks) from one of the HT leads.

So cylinder 4 is getting a weak spark, which leads to misfires. So that I may be of help to the next guy, here are the symptoms you may look for:

1) The bike idles lumpy
2) When hot (200+) the bike will be very choppy on the throttle
3) When cold and at idle, you will smell unburnt fuel from the pipes
4) When cold/warm and occasionally, the bike will bog down when trying to pull away slowly

I now have to buy new HT leads and possibly new ignition coils. One HT lead is $ 57 and a coil is $ 98.

Thanks for the advice guys, helped me narrow down the culprit.

Peace

Thanks for following up! You could do a fleebay and roll the dice??? Glad you peaked! Also an empty tube to the ear helps block other sounds and funnel arc-cover when this needs done in the day light. Or as my brave and foolish uncle used to do, just run your hands over the wires! :thumbdown: (Don't do that it hurts when they're bad).