Good discussion on this topic, unfortunately for some reason I cannot reply after scott's post so I've started another.

Good points and with my experience yesterday, I have to agree... this seems to be a fuel curve issue.

Running 3rd gear at 45 mph seems just a tad high (overall it's humming just a bit too much). I can live with it but a torquey monster like the 1700 R* should be good to go in 4th gear at 45 mph without sputtering. Oneperfectrun seems to be having the same issue and I can tell you that 5th gear at 50 mph has the same result. This must be an issue with the computer FI.

I do have aftermarket pipes (Cobra) and a BAK, the one with the big V and 102 CU IN on it.

Since I'm new to the FI world, what do we do to try and fix this issue? (Sorry scottw, I got lost between the fuel curve and your discussion about adding a 1/2 step to your needle).

Check out this calculator of speed/rpm. You will see that 50mph in 5th is 1760rpm. These things are torque monsters, but ya gotta get at least a few revs into them. I love short shifting and lugging the engine, and I am never in 5th til 60-65 and that is only on a level road.

fireman922 wrote:
Check out this calculator of speed/rpm. You will see that 50mph in 5th is 1760rpm. These things are torque monsters, but ya gotta get at least a few revs into them. I love short shifting and lugging the engine, and I am never in 5th til 60-65 and that is only on a level road.

My '07 R* isn't happy in 5th gear until about 60 mph. I jokingly say it doesn't like to drive 55, but it's true. I usually don't hit 5th until at least 60mph. 55mph in 4th sounds like I'm winding it out a bit, but in 5th it grumbles....I was surprised once I put a tach on mine just what rpm's the bike seemed to run best at. 2000 rpm's is a good beginning for about any gear, and 2500 rpm's seems like you're starting to wind it out. But let's face it, 2500 rpm's just isn't that many spins for this big old engine. It just 'sounded' a little too fast before I got the tach installed. Now I can drive without the speedo just by looking at the tach and sensing how the engine sounds and responds to the throttle. I almost don't use the speedo anymore. It's hard to read in the glare, anyway, and I usually don't like taking my eyes off the road to check it.
John Scribner

alltimeqb wrote:
Good discussion on this topic, unfortunately for some reason I cannot reply after scott's post so I've started another.

Good points and with my experience yesterday, I have to agree... this seems to be a fuel curve issue.

Running 3rd gear at 45 mph seems just a tad high (overall it's humming just a bit too much). I can live with it but a torquey monster like the 1700 R* should be good to go in 4th gear at 45 mph without sputtering. Oneperfectrun seems to be having the same issue and I can tell you that 5th gear at 50 mph has the same result. This must be an issue with the computer FI.

I do have aftermarket pipes (Cobra) and a BAK, the one with the big V and 102 CU IN on it.

Since I'm new to the FI world, what do we do to try and fix this issue? (Sorry scottw, I got lost between the fuel curve and your discussion about adding a 1/2 step to your needle).

Was just explaining the exp i had with carb'd R*'s tweaking needle adj slightly richer to fix a slight lean issue it had thats the same issue you seem to be having with your FI setup where the fuel curve mapping may be incorrect etc causing the issue on your bike with the aftermarket exhaust & BAK you installed requring fuel enrichment thru the entire fuel curve.

Scott

agree'd on curising at too ow of an rpm esp in 4th & 5th gear.

On flat road with little to no headwind i would not cruise in 4th or 5th gear at anything less then 2100-2,200rpm esp if ridding 2 up.

It's ok to cruise at 2k rpm in slow traffic arround town in 2nd & 3rd gear @ approx 2k rpm or maybe if on a flat country road cruising in 3rd at 2k rpm just looking arround at the surroundings .

But in general 2,100-2,200 rpm would be the minimum cruise rpm i'd run when crusing in higher gears like 4th & 5th on lvl ground . But cruising at 1,700-,1,800 in 4th and esp when in 5th gear is just too low lugging the motor too much IMHO.

To me a sweet cruise rpm for the R* with stock cams is inbetween 2,200-2,500 rpm but even crusing at 2600-2700rpm @ 70mph with 31t pulley also seems like the R* motor is fine with it. That cruise rpm is esp helpfull when hitting lrg mountains on interstate when ridding fully loaded 2up on the interstate with headwinds & tall windscreen where the motor is running in the heart of it's trq/power curve to better handle the steep grades with not much more throttle required to keep it at 70mph.

Scott

Ok, here's the latest.

There is a specific rpm/speed correlation which creates this sputtering point. 50 mph in 4th gear, it happens.

But I now know that the AIS is removed. The O2 sensors are no longer hooked up but there are bungs on the Cobras for them. Wondering if that is what's causing the sputter?

The other thing is that I don't know if this has a PC or anything. How would I find out??

Thanks guys.

alltimeqb wrote:
Ok, here's the latest.

There is a specific rpm/speed correlation which creates this sputtering point. 50 mph in 4th gear, it happens.

But I now know that the AIS is removed. The O2 sensors are no longer hooked up but there are bungs on the Cobras for them. Wondering if that is what's causing the sputter?

The other thing is that I don't know if this has a PC or anything. How would I find out??

Thanks guys.

My 02's are hooked up and it does it also. Don't think thats gonna be it.

Oneperfect,

Are you running the stock program? I think I am but I have no idea.

So is there ANY solution to the issue?

Thanks.

alltimeqb wrote:
Oneperfect,

Are you running the stock program? I think I am but I have no idea.

So is there ANY solution to the issue?

Thanks.

All stock. Pipes are the only thing I've done to it. Oh and I have the AIS disabled.

My AIS is removed as well but a quick run tonight has me concerned...

I was taking a run to the local Wally Mart to see if they had Mobil 1 V Twin when the sputtering got worse than it's ever been.

This was a 10 minute ride there and after a stop about 3/4s of the way home, the bike was idling weird. When I got home it was almost like I had left a spark plug wire off, the idle was not sounding its typical self. I shut it down and the first thing I noticed was that the exhaust didn't smell right.

I am letting it cool off and will take the tank off tomorrow after work, check all the plugs, replace the oil with the M1 V Twin and see what happens.

The only thing I've done to this bike is to change the oil and filter using the drain both bolts, replace filter and fill with 4 quarts method. The only other thing that is different from my prior miles ridden is I put about 2 gals of mid-grade gas in her... wondering if that was a mistake.