M1000 low end stumble - anyone taking fuel out at 3500-4500?

[1badhusky]

I've got y-pipe, intake and a can on a 09 M1000, it's always had a low-end stumble since I bought it. Got worse last weekend when it was warm.

So, I'd already been at -1 at low throttle 5, 10, and 20% from 3500-4500 where the stumble is, but thinking about going to -3.

Anyone else have map numbers down there at those rpms? I don't have an egt or af sensor, so flying blind - I know, need to get something, but won't have it before my next ride.

Any advice?

 

[mphfreak]

I've got y-pipe, intake and a can on a 09 M1000, it's always had a low-end stumble since I bought it. Got worse last weekend when it was warm.

So, I'd already been at -1 at low throttle 5, 10, and 20% from 3500-4500 where the stumble is, but thinking about going to -3.

Anyone else have map numbers down there at those rpms? I don't have an egt or af sensor, so flying blind - I know, need to get something, but won't have it before my next ride.

Any advice?

Check out the thread " m1000 running strong with BD #`s " The lower numbers for 3000, 5000, and 6500 will work for you.

 

[1badhusky]

yeah, i looked at those numbers, and i was already at -1 at low rpm, so now I'm going to try -3, but that's what's got me a little worried - taking out that much fuel - but not sure what else to do.

 

[mphfreak]

I tried -3 at the 3000 range and found my sled stumbled. As i went up the sled ran better. You may have to try a little higher. You will not hurt your sled running lean at those ranges. You cant possibly hold 3000 rpm for long enough to burn down and you cant make enough heat at that rpm. The most ive seen is 1000 degrees between that and 5000 rpm. Now different story at 6500 rpm I will see numbers up to 1230 degrees if i can hold the rpm there for a stretch. Dont be scared to play with your boondocker at 5000 and less.

What can do you have? My slp can works great but I have heard there are a few (MBRP) have gave trouble at bottem end. Try putting your stock one on and try the numbers you are running. May just be that? Just a suggestion.

 

[moyiesledhead]

I'm at -7 at 3000 with an SLP single set. Still pig rich when it's cold but seems to clean it out when it warms up. Pretty sure I've got a broken reed though. Summer project. Might wanna check yours if it seems to be getting worse.

Like freak said....pretty hard to hurt it at that rpm. If you go too lean it just won't start or stay running at idle. I've been there and that's what happened.

 

[1badhusky]

I'm at -7 at 3000 with an SLP single set. Still pig rich when it's cold but seems to clean it out when it warms up. Pretty sure I've got a broken reed though. Summer project. Might wanna check yours if it seems to be getting worse.

Like freak said....pretty hard to hurt it at that rpm. If you go too lean it just won't start or stay running at idle. I've been there and that's what happened.

Thanks - good to know I'm not the only one going way negative down low - rode it today at -3 to -4 from 3k-4.5k and it ran better but still some stumble, gonna go -4 and -5 next time.

Mine seems to do opposite - runs good cold but as day goes on it gets worse.

 

[Uturn]

My 08 (still has 08 map) is -5 across the board at at 5000, still a bit rich at -5 with EGT's and plugs. I'm going to add a fuel pressure regulator this summer to see if I can get better control. I have full SLP pipe and intake.

I bought the sled not knowing the reeds were screwed, and changing them helped a lot to cleaning up the bottom end.

If you've never done reeds on a laydown engine, it's about a 10 hour job!! A 10mm ignition wrench makes it way easier to get the bottom bolts out of the reed cages. You also need to pull off the bellypan.

 

[killerrf]

on my m1 with full slp, open intake, pc3 i had to add like 5% more fuel at idle... there is 10% more fuel from 2000 to 4250 rpm at 10% throttle
and 6% more fuel from 2000 to 3750 rpm at 20% throttle. then 2000 to 6000 rpm there is no fuel added from 40% to 100% throttle.

from idle to WOT mine runs perfect. no bog or hesitation.

14% to 15% more fuel at WOT

 

[1badhusky]

on my m1 with full slp, open intake, pc3 i had to add like 5% more fuel at idle... there is 10% more fuel from 2000 to 4250 rpm at 10% throttle
and 6% more fuel from 2000 to 3750 rpm at 20% throttle. then 2000 to 6000 rpm there is no fuel added from 40% to 100% throttle.

from idle to WOT mine runs perfect. no bog or hesitation.

14% to 15% more fuel at WOT

What year? I'm adding up to +5 (that's 50% I believe) around WOT. Crazy that some sleds need to add fuel where others have to take so much away in the same spot.

I went to -5 at 3750 (2,5&10%), where the worst stumble is and it helped, but it's still there, so going -6 and reducing to -3 to -5 all around that area.

 

[0neoldfart]

The M1 produces a lot of engine heat, and at low speeds you are preheating the intake air, not to mention they are mapped rich from factory - those who are adding fuel at lower rpm's likely have less fuel pressure. On mine, with 43 psi at idle, screen hood, and open airbox the sled runs crisp all the way through the rpm range - plug color, piston wash, EGT's and seat of the pants verify this - but I did remove fuel with a PCV and laptop. This is an 07 with 09 mapping. The 08 map (recall item), was the worst thing done to the sled - I spent most of the winter trying to tune around it. Get the 09 flash, vent the crap out of your hood, and let the machine breathe. Tune your BD box based on plug color and piston wash, don't rely on EGT's alone.