POWER LOSS

Hey,

Out for a equipment check ride and seem to have loss top end. I have the usual mods AIS,Flapper, Open airbox, FMF Power bomb and Q4 muffler, and FMF programmer set @ 3.3.(1.5).8.4.4. The engine check light came on for about 5 minutes and I seem to have no W.O.T. I have it geared @ 13/43 Stock and can barely get up to 70-71mph and 8500rpm max I've had it gear up to 13/47 and have had it up to mid 80's previously. I'm suspecting a problem with the FMF fuel programmer (only 2 months old).
Anyone have any Ideas or similar problem that was corrected?

It's been noted numerous times in multiple threads here that the FmF programmer has a glitch in the 5th number.

Take it to 6, or higher and see if that fixes your problem.

I do not know, but it should be relatively easy to check.

At least I know it'd be easy to check on my Attitude Industries programmer which is almost exactly like the FmF unit.

There should be a mode selection that allows you to cycle through each setting to see what number has been selected.

motokid wrote:

I do not know, but it should be relatively easy to check.

At least I know it'd be easy to check on my Attitude Industries programmer which is almost exactly like the FmF unit.

There should be a mode selection that allows you to cycle through each setting to see what number has been selected.

Hey motokid;

Just got back from running 2 test runs on the WRR. First test was I upped the 5th place digit from 4 to 6 as you suggested. No difference what so ever from my limited 15 mile loop which included curves, hills and straights. Only when I got going down a long steep hill could I even briefly see 84mph and 10,000rpm. On the flats I had trouble maintaining 69-71mph @ around 78-8100rpm. I even looked at the filter as suggested over on the ADVrider forum; (it was fairly clean) so I removed it for 2nd run, and was able to get it to rev a little freer, but not much more W.O.T. response. Tomorrow I will have to remove the programmer and try another run to see what effect it has. Do you have any other suggestions to try, I don't want to have the bike down for any length of time as this is a primo time of the year for me for riding.

If you recently had the fuel tank off, check for a kinked/pinched fuel line.

Check to see if something is blocking the airbox air inlet.

So strange.

Can you hit rev limiter in lower gears?

2,3, and 4th gears?

motokid wrote:

So strange.

Can you hit rev limiter in lower gears?

2,3, and 4th gears?

Motokid,

I think I can, I put it in 4th and got it up to 10,500rpm which should be near the rev limit. Just doesn't want to go in top gear. I could test it in all lower gears if you think it would help. But it will have to wait until after the rain storm (East Tennessee); possiblly late this afternoon (EST zone).

Paul

How do you know what rev you're in? Are you running in CO mode all the time?

motokid wrote:

How do you know what rev you're in? Are you running in CO mode all the time?

No I'm running the TTO RPM/Hr meter gauge. It is only reading every other crankshaft rotation...so I have to just mentally double the reading to get the correct RPM.

ps. I'm beginning to suspect that part of the problem may just be an over tall gearing problem and my wind resistance (240lb) except for that engine check light coming on for 5 minutes during the original ride (previously mentioned), and that nothing seems to happen for the last 1/2 inch of throttle twist up to WOT. I may switch back to 13/47 gearing and try it before pulling out the programmer. I assume that your EFI programmers don't have the acceleration (5th digit) parameter problem.
http://www.trailtech.net/tto.html

No. The Attitude Industries efi tuner does not have issues with the fifth number setting.

I'd be surprised is gearing is your issue. I guess it's possible, but I struggle to understand it appearing like that.

I've never hit rev limiter in 6th gear with 13/48 gearing. I top out around 85mph with that gearing. (I have a corrected speedo for the gearing I'm running)

How long have you had the FMF programmer added in relation to the loss of power? Did you change anything immediately before the power loss? You mentioned being loaded up with luggage... its amazing how much drag panniers (as well as any other luggage that sticks out in to the wind stream) adds and therefore how much power it robs.

You should try dropping the WOT fuel number (3rd setting) to 0.5 instead of 1.5 imo, the bike runs rich enough at WOT. Or, just disconnect the programmer and go for a ride. If your power comes back, its the programmer, if not its something else. You'll be fine without the programmer, I ran without one with the same mods for nearly 10k miles.

pfy50 wrote:

I have it geared @ 13/43 Stock and can barely get up to 70-71mph and 8500rpm max

I'm not so much questioning the 6th gear top speed as I am the part I quoted above.

70 mph with stock gearing, regardless of size (unless you weigh over 400 pounds - which you don't) should be easily attainable in 5th gear, let alone 6th gear.


With stock gearing, most adults males can pull 90 to 95 mph. I assume most of those people don't weigh 110 pounds.

Something is not right if you can't get past 70 mph in stock trim.

The next time I ride my X I'll check to see where I hit rev limiter in 5th gear. I'm pretty sure it's around 70 mph

click me <-- check here.....

How could drag be an issue if you can get to 87 mph in 5th, but slower in 6th?

I think drag is an issue on these bikes with anybody above 90 mph anyway though.

87mph in 5th gear MUST be with stock gearing right? No way your doing that with 13/47.

motokid wrote:

How could drag be an issue if you can get to 87 mph in 5th, but slower in 6th?

87mph in 5th gear MUST be with stock gearing right? No way your doing that with 13/47.

Nope 13/47, but I only got that once with a long run with a down hill grade to get started.
Drag always effects top speed just less if you have the proper gearing to overcome it better. (As in direct drive = or > 1.0 to 1.0 ratio as opposed to overdrive with<1 to 1.0; currently 0.888 for 5th and 0.786 for 6th gear). You only feel the drag at the higher speeds with the wind in your face and chest, but it is there at ALL speeds. It is a law of aerodynamics. I'm sure the bike would get in the 88mph area if it were on a dynamometer with no wind resistance(Drag) in 5th; theoretical top speed is 98.7mph for 13/47 at rev limit 11,500, but not likely to ever see it in overdrive.
See http://www.gearingcommander.com/

I don't care what gearing commander says.

I know real world what I've seen with 13/48 gearing.

There's not a snowballs chance in hell I could see anything above 80mph in 5th gear.

I will find out this weekend where 5th gear hits rev limiter.

But I'm gonna say your speedo was way off, or your gps or whatever you were using was off, or you misread it to see 87 mph in 5th gear with 13/47.


Something is surely off or the grade of the hill you were going down was quite steep and very long.


When I do "top speed runs" I do them on flat ground with no help from cars or trucks or drafting or anything.


Since the gearing is so short in the last two gears I see no way hitting rev limiter in 5th, then shifting to 6th would result in a loss of speed regardless of your size and weight. I can see not gaining much in speed, but I can't see losing it regardless of gearing.


Which comes back to your power loss title.


Something surely can't be right.

2008 wr250x
speedo corrector - 12 o'clocklabs unit
13/48 gearing
Attitude Industries EFI programmer
AIS removed
Airbox door removed
FmF Q4 exhaust slip-on
Stock header
Distanzias that are well worn

I weigh 155 pounds - 5'7" tall

5th gear top speed at rev limiter today

76 mph

I did this on three separate occasions today with different road conditions, and not really tucking in for minimum drag.



All I can say is - I don't believe you.
No way you got over 85 mph in 5th gear with 13/47 gearing.

One of us has serious problems.
I was able to shift into 6th gear and keep climbing in speed past 76 mph before I had to back off.

I've know I've never seen anything north of 85mph in 6th, with the above setup, and a mile-long run in 6th gear with no letting off.

Which pretty much coincides with what many other people say who have similar gearing.

Stock gearing should get you well into the mid to upper 90 mph range.

Going up 5 or 6 teeth in rear is going to drop that top speed by 10 mph.