Where is my horsepower?

[George S]

I have a 2004 s4r that I bought with 12,400 miles, a full Titanium Arrow exhaust, and a Dyno Jet PC. The bike now has 18K miles and I have changed the oil, plugs, and air filter (k&n), flushed the radiator, and had a valve job done at about 15K miles. and for the record i weigh approx 170 pounds.

Today I rode some back roads and on a open stretch I couldn't get my bike even to 100mph! I was giving it everything i could and it was REALLY struggling. this is my first duc and i've never had it go faster than 80 or so. but today the engine seemed very noisy; sounded like the valves. is that normal?

anyway, any ideas where I should start trouble shooting? I feel like the bike should have more power than that. should I just take it to the local race shop and have them stick it on the dyno and tune it that way?


thanks for the input!
George

[Dirty Duc]

If that bike won't do the ton, there is something wrong with it.

What exactly remains to be determined... and I bow to those with more specific experience.

All I know is that no aircooled monster I have ridden has had a problem with power.  A watercooled bike should have less problems with power. 

[Ddan]

Check that both cylinders are firing

[Slide Panda]

+1 to that, it's my first guess.

That bike should have no issues getting to that speed.

[jerryz]

a dirty fuel filter will give those symptoms

[ducpainter]

Check that both cylinders are firing

yup

...and

a dirty fuel filter will give those symptoms

yup.

[George S]

forgot to mention... I have replaced the fuel filter as well.

[ducatigirl100]

only one or the hole gang !   


Before doing anything check if your clutch plates are all worn down ... from the symptoms it really looks like that's the problem ...


I'm sharing my personal experience .   


if  you fiber plates look like that it's time to change ...    ( after 48000  Km )

[Roaduser]

im sorry but his description didnt say anything about his clutch slipping... it sounds more like a lack of power than a lack of friction/traction.

im leaning towards its running on one cylinder. unless your familiar with the ducatis, it can be deceptive. many ppl will think its running on two when its not and u certainly wont be the first or the last!

did u change the fuel filter before or after the issue?

[George S]

only one or the hole gang !   


Before doing anything check if your clutch plates are all worn down ... from the symptoms it really looks like that's the problem ...


I'm sharing my personal experience .   


if  you fiber plates look like that it's time to change ...    ( after 48000  Km )

I'll take a look at the plates and get back to you. I'd be ecstatic if it was that simple of a fix. I've been suspicious of the clutch slipping anyway. And the drag probably increases exponentially once you get up around 100mph.

[George S]

im sorry but his description didnt say anything about his clutch slipping... it sounds more like a lack of power than a lack of friction/traction.

im leaning towards its running on one cylinder. unless your familiar with the ducatis, it can be deceptive. many ppl will think its running on two when its not and u certainly wont be the first or the last!

did u change the fuel filter before or after the issue?

If this is a possibility, i'll look into it. My only experience with a cylinder misfiring was in a four cylinder car... and the thing ran like crap! I mean it was sputtering and jerking and everything. Not so with the duc. But maybe the engine configuration allows them to run well on only 1 cylinder. How do I check that? Just pull out the individual plugs and make sure they're firing? If i'm going there I should prob check the compression in the cylinders too. Is that number in the service manual? If not do you know what the compression should be?


Thanks!

[zooom]

did u change the fuel filter before or after the issue?

curious about this also....if it was before, perhaps the line is slightly kinked and not allowing proper flow at full tilt boogie?

[Slide Panda]

Get/borrow an infrared thermometer. If one cylinder is not firing, running the bike, and measuring the header temp close to the head will quickly reveal if one is heating up while the other is not.

Or you could use you hand - just be careful. Either way do this checking from start up when the bike was cold before.

Checking for spark is easy to do too. Couple ways to go about that - on my 900 has the wires are easy to get to I'd just pull one and try to fire it up and reverse. If it fires and runs like it has been in one config and not the other... well you've got no spark. There's various spark test tools one can buy w/o much cost - or the old pull the plug, ground it on the head and hit the starter method...

[George S]

curious about this also....if it was before, perhaps the line is slightly kinked and not allowing proper flow at full tilt boogie?

I'll check and see

[George S]

im sorry but his description didnt say anything about his clutch slipping... it sounds more like a lack of power than a lack of friction/traction.

im leaning towards its running on one cylinder. unless your familiar with the ducatis, it can be deceptive. many ppl will think its running on two when its not and u certainly wont be the first or the last!

did u change the fuel filter before or after the issue?

fuel filter was changed before the issue... shortly after i purchased the bike