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Discussion Starter #1
Just got a 2002 M750... I used to have a 1997 M750, but sold it 5 years ago, so its hard for me to remember, but this new one seems to run rough.

I remember the monster having lots of power on tap from down low in the RPM range... this one seems to shudder until it gets to 4000 RPM... still in break-in (160 miles so far) so I have not brought it up past 6000 rpm, but it just seems kinda weak.

Since I dont know jack about this stuff, I am looking to you guys to help me out here... Now here comes the questions...

Where does the power band start? Are my memories just fogged, or do you have to rev it past 4000 to get any power out of it?

Is this a mapping of the EFI issue? Do they have just one map at the factory, and apply it to all bikes, or do they tune it per bike?

If it shudders down low, does that mean that it is rich or poor? What the heck does that mean, rich in fuel or rich in air?

Will the dealer (4 hours away BTW) fix this at the 600 mile service? is it common?

Would slip-ons and a powercommander (or whatever) fix this? I plan on doing it someday, but not until I get up the cash.

Can the dealer re-map the existing chip?

Thanks in advance!
 

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Probably not too much help, but I thought that the bike shuddered at low rpm's too, but I think that i'ts more of a low speed thing, the motorcycle is so high geared that at too low a speed, it seems to shudder, and rich and lean refer to the fuel, rich= too much fuel, lean= too little fuel, someone else can probably answer all the other questions, I just ajusted my riding style, and learned not to lug the motor too much, and it took care of most of the shuddering.
 

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My little 620 is also rough low down. I figure it's probably the lean mix these things have to run to meet emissions and noise requirements. My dealer can remap existing chips and next week at the 600 mile checkup I'll have megaphones and an open airbox for GP to dyno and remap for. I expect that to smooth out the leanness in the midrange, and maybe lower down.

If it persists, I'll see if I can find a bigger rear sprocket as I'm not too keen on having the chain wrap around a smaller front one.

The only real experience I have here is in rejetting a carbed '02 (Brand X) bike for an open pipe and airbox, and once I finally got it right it made a HUGE difference in the low end and midrange.

-Don
 

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It's likely that your 750 is on the leaner side of what is delivered from the factory, which is fairly lean anyway.

The dealer can synchronize the throttles, and can do a limited amount of lower RPM mixture adjustment on the stock ECU. Folks have had this done and reported significantly improved drivability. I recommend you have the dealer do that at your 600 service before you dish out for a PCIII or whatever.

General consensus is that slip-ons don't get you much (if any) horsepower, but you do get to hear the wonderful music a Ducati is capable of. Usually they make it a bit leaner, again it's usually within the adjustment range of the stock ECU. Other benefits are looks and more cornering clearance....

AFAIK, the late model IAW 5.9 ECU is not remappable or rechippable. It is only slightly adjustable in the lower ranges.
The older ECU's are rechippable, but I don't currently know what years they were fitted. Time for some research on my end......

If you're going to run an 'open airbox', you will need some form of help on the ECU. There is the PowerCommander PCIII, a TechLusion(?) or the FIM Ultimap.

I got a PCIII just to gain relatively complete control of the mixture. I've got the equivalent of 'slip-ons' and they made it slightly leaner. The PCIII with one of the maps provided on the CD improved it some. A dyno-tune improved it a bunch.
 

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My wife's '02 620 never had any problems. Riding her bike is pretty fun compared to my S4. I think the biggest problem is with the gearing. Right now you are breaking it in and are probably running pretty low RPM's. I am not sure what the spocket size is on the 750, but I know the 620 is geared in a way that if I changed the size, it would have a very short top end.
Keep breaking it in, don't be afraid always ride in the 4000-5000 RPM range, you might notice a difference. The PCIII and all of that stuff will help a lot and make things really smooth, but you can't tell that untill after the break in. I guess that I really didn't help, but maybe reasured you some what. :p
 

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Go up two teeth in the rear. These bikes are geared to high from the factory to keep the noise levels (rpms) down at highway speeds. This tends to give you chugging at low speeds.
 
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hmm I just order a 14 tooth front sprocket...going down one tooth...so what's wrong with it compare to going up rear sprocket? confusing...
 

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Both have the same effect. Going down one in front is approximately equal to going up four in the back.
 

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Discussion Starter #9
I get chugging at highway speeds when my RPMs are under or at 4000.

I guess I will drop a tooth in the front sprocket after the 600 mile... As well as have the dealer look at the EFI.
 

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I get a snatchy/luggy feeling out of my '02 750 at very low RPMs (don't know how low; the %(^&%* tach is still busted). But it certainly clears up well before 4000rpm. To my ear, it seems like around maybe 2000-2500 where it stops shaking; in steady traffic I'll routinely run it at 50-55mph in fifth gear with no trouble. If you're just getting that luggy feeling, but it's not missing or hesitating, I'd just attribute it to it being a decent-size twin with a light flywheel and a chain drive. I find that the tendency is exacerbated when my chain's real loose; you might want to check that.

BTW, it mystifies me how many people are bothered by the M750 gearing - when it's already running 5500rpm at moderate highway speeds in fifth! I mean, yeah, the ratio spread is narrow and first is pretty tall, but provided you're going more than about 15mph, it's really not an issue... To each his own, I guess. :)

M.
 
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My 2k2 M750 was pretty iffy at low rpm. I took it in for the 600 mile service and it came back a whole new bike. In gears 1-3 it revs like it never did before. I think DNA imports the bikes really loose for break-in!

Dealer adjusted the FI to very nice effect, crisp throttle response now.
 
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