Engine braking (slowing the bike down) is excessive

[Ridgerunner1061]

Good Day Everyone:
A few of my friends got together for a long distance ride to Yosemite. I complained about how hard my bike would slow down when you roll off the throttle. Well a couple of my friends thought I was exaggerating so they tried my bike and they were shocked at how the slightest reduction in throttle brought on the engine (braking) slowing the bike down. So then I rode their 919 and I was right my bike brakes much harder than his when you adjust the throttle. My bike has 20,000 miles on it new tires (inflated properly), new chain (which was installed and adjusted by the shop) and fresh engine oil.

Any ideas of what is going or gone wrong of is this a normal FZ trait?

Thanks for your help.

 

[sxty8goats]

Yes, the throttle seems to cut off too hard. I find that she responds better if I'm higher up in the RPM range. Say from 6,000 to 9,000 she responds 'smoother' to throttle input than down below 5,000 RPM.

A lot of people complain that the clutch is on/off. I've never had a problem with the clutch. I do hate the way the throttle cuts out with a slight roll back.

 

[motopete]

I think that a sign of good compression.

 

[fureinku]

do the airbox mod and open her up, it will help a tad..

 

[Shamus McFeeley]

do the airbox mod and open her up, it will help a tad..

The 919s compression ratio is 10.8:1 the FZ is 12.1:1. This could have something to do with it. You also have to consider that the bikes are probably geared somewhat differently. There's nothing wrong with engine braking, if anything, I'd rather have more than less engine braking.

 

[sxty8goats]

The 919s compression ratio is 10.8:1 the FZ is 12.1:1. This could have something to do with it. You also have to consider that the bikes are probably geared somewhat differently. There's nothing wrong with engine braking, if anything, I'd rather have more than less engine braking.

I agree with that. I just feel the throttle curve is a bit steep. It seems to close a lot faster than I would expect as I roll off below 5000k RPMs.

 

[cap'n]

You could have a sticking brake caliper.

Center stand -> rotate front and rear wheel by hand.

Should have a slight drag, as the pads stay in contact with the rotors, but you should be able to turn it with one hand and not much effort. You wouldn't notice a stuck caliper on acceleration because you'd just give it more gas. But when you let off, you'd notice bigtime.

 

[proline]

I agree, it is a sign of good compression......FZ6 does that

 

[RJ2112]

It's a relative thing..... twins have a lot more engine braking compared to most inline 4's. If your FZ6 is operating 'normally', how much it slows on closed throttle shouldn't be a huge difference. I've ridden a wide variety of bikes; the FZ6 isn't unusual in this department.

If you and others can see a significant difference, something may well be dragging on your bike. Front or rear brakes dragging would contribute as described by another poster. Engine breathing may be a part of it, in the form of a dirty air filter. Or a clogged cat, or muffler.... but that would be unusual with FI keeping things nearly perfect ratio wise.

A rusted chain is another possibility. So are bad wheel bearings.

If you have saddlebags mounted, they will act like an air brake.

 

[paulinus]

My dad has an 07 919. I too noticed the difference in engine braking btwn the two bikes. I like it myself. Not that I dislike the 919. It's just a difference btwn the two bikes. Just my 2cp. Both bikes have a lot more engine braking than his 1980 CB750.

 

[tuningfork]

is the idle speed set too low? you can raise it a tick and this may help.

 

[Kriswithak]

I find it a problem only going from second to first, or starting higher, say third, second then first quickly. Its actually quite easy to lock up the back wheel if its wet or the tyres are cold.

Do you have a stock exhaust? I am inclined to think that might be the problem. The bike is much more on/off on the throttle with the stock exhaust.
Otherwise what others have said, something might be sticking!

 

[RJ2112]

Another factor may be whether the bike is still at the OEM sprocket sizes. -1 f +2 r will increase the engine braking effect by ~10% as well.

 

[TownsendsFJR1300]

Something not noted above, the FZ6, like my FJR, shuts off the fuel injectors in a deceleration situation. Its to save fuel and is part of the problem on the on/off throttle sometime complained about.

Carbs generally have a little bit of fuel being pulled in upon deceleration, the fuel maps on each different bike will make a difference too...

I would check the brake dragging, wheel bearings, chain, tire pressure, etc, just to rule those out for safety reasons.

 

[chuckfz6ryder]

is the idle speed set too low? you can raise it a tick and this may help.

My idle is a little low, always has been. One day I decided to set it to spec, went for a ride and realized I lost a lot of my engine braking. I went back to low idle, I like the way it slows down when you roll off the throttle.

 

[ready2goriding]

Is it possible the 919 has a slipper clutch?