MPI Apex running lean at cruising rpms

[347strokin]

Hey guys,

Just got back from 3 days of riding in McBride. The sled ran awesome and finally seems to be close to being dialed in.

My only issues were that during 1/2 to 3/4 throttle openings and cruising the A/F #'s would be hitting 13 to 14 and every once in awhile would get close to 15. Anytime I blipped the throttle the A/F's would come around. And WOT the A/F's are about 11.8

Am I going to damage my motor while running these A/F #'s while cruising?

I'm running a Rapidbike 3 with a low and a high elevation fuel map. I'm also running 12 lbs on a Stage 2.

Thanks!

 

[MOUNTY]

I have been observing the same thing with my Nytro, I havent really played with the Gems yet but when in dought call the company that makes them. They will have the most experience out of anyone. I was informed that as long as WOT was not above 12.5 you should be OK but hitting 15 is rediculous no matter what stage of throttle in my books, lean is lean.

 

[347strokin]

I have been observing the same thing with my Nytro, I havent really played with the Gems yet but when in dought call the company that makes them. They will have the most experience out of anyone. I was informed that as long as WOT was not above 12.5 you should be OK but hitting 15 is rediculous no matter what stage of throttle in my books, lean is lean.

I'm sure MPI would confirm that 11.8 is a great A/F number to see across the board.

But I thought I've read some threads here that guys are seeing lean #'s on cruising rpms on the Apexes and are riding them without issues. I realize 15 is way too high but that is only a very small rpm range that I could see that. Most of my cruising is showing 13-14 A/F.

 

[quebecmoutainrider]

If you have a gems..then why not just adjust the setting in the WOT range. this unite has a setting for idle and midrange and then WOT....my sled would choke at idle when I was on the trail ridding or just starting off..as long as it went to idle..it would choke..at G-Force they told me to rich the idle up..#1..which is the green light.on the gems.now it rocks..no more trouble..so why not just adjust the richness of the thing at WOT..this should lower your numbers.I think...but talk to someone who really knows there stuff...I am still in the learning process..send a PM to Jan-o (rxrider ) he should know..
#1 is for idle
#2 is for midrange
#3 is for WOT
these are the things that will make the difference.you must do this when the sled is warm and on idle...you can also change the altitude and the boost with the gems..didnt they give you a manuel..mines in french..so still trying to understand it..lol..13 is ok and even high 13..if you have a shim.my sled is running 13 psi..which is the lowest it will go..and running 92 octain..WOT at 12-13 A|F..learn how to use this gem and you can just turn the key and ride..I have numbers for trail ridding and also change them for when I ride off trail..the load on the track is different.like when you are WOT going up a hill and cant let off.this unite is great..and with my prologger..I have an idiot light that flashes..and it records..so to tell you the truth..the last time I rode,Ididnt even look at the numbers. .lol..

 

[347strokin]

If you have a gems..then why not just adjust the setting in the WOT range. this unite has a setting for idle and midrange and then WOT....my sled would choke at idle when I was on the trail ridding or just starting off..as long as it went to idle..it would choke..at G-Force they told me to rich the idle up..#1..which is the green light.on the gems.now it rocks..no more trouble..so why not just adjust the richness of the thing at WOT..this should lower your numbers.I think...but talk to someone who really knows there stuff...I am still in the learning process..send a PM to Jan-o (rxrider ) he should know..
#1 is for idle
#2 is for midrange
#3 is for WOT
these are the things that will make the difference.you must do this when the sled is warm and on idle...you can also change the altitude and the boost with the gems..didnt they give you a manuel..mines in french..so still trying to understand it..lol..13 is ok and even high 13..if you have a shim.my sled is running 13 psi..which is the lowest it will go..and running 92 octain..WOT at 12-13 A|F..learn how to use this gem and you can just turn the key and ride..I have numbers for trail ridding and also change them for when I ride off trail..the load on the track is different.like when you are WOT going up a hill and cant let off.this unite is great..and with my prologger..I have an idiot light that flashes..and it records..so to tell you the truth..the last time I rode,Ididnt even look at the numbers. .lol..

Thanks for the info but I'm running the RapidBike 3.

 

[tapex_07]

What are you seeing for boost at 1/2 throttle?? Just cruising? If it's not in boost, its ok. Afr's like that would be ok. Because an n/a sled should be 14.7. So if your not seeing ANY boost I would think your ok. I bet the throttle response is great at half throttle cruising, instant. Now if your seeing boost I would adjust and add fuel.

 

[347strokin]

What are you seeing for boost at 1/2 throttle?? Just cruising? If it's not in boost, its ok. Afr's like that would be ok. Because an n/a sled should be 14.7. So if your not seeing ANY boost I would think your ok. I bet the throttle response is great at half throttle cruising, instant. Now if your seeing boost I would adjust and add fuel.

That's one thing was worrying me because I am seeing a pretty constant 5 lbs while just cruising around. And definitely instant throttle response...lol

I might just have to pony up and get the tuning software for the RB 3 and start tuning myself. I did have my fuel maps looking really good but then I installed a cold air snorkel and under tunnel exhaust so this might be why I'm running a bit on the lean side now.

 

[Wildman]

Yep, all you have to do is richen it up in the rpm & boost area your lean at with the RB3. No big deal. You could bump your static fuel pressure up a couple pounds too if your running a adjustable regulator that is.It seems you are still running a little lean through the mid range & 11.8 is about as high as I would go using pump fuel at WOT unless of course your using Meth than its perfectly fine actually a little fat.

 

[347strokin]

Yep, all you have to do is richen it up in the rpm & boost area your lean at with the RB3. No big deal. You could bump your static fuel pressure up a couple pounds too if your running a adjustable regulator that is.It seems you are still running a little lean through the mid range & 11.8 is about as high as I would go using pump fuel at WOT unless of course your using Meth than its perfectly fine actually a little fat.

No meth on the old Apex. I had my last few fuel maps made at E and S Motorsports near Edmonton so I havent had the pleasure of doing it myself. But it looks like it's time to make the plunge. Thanks for all the info. Damn it's good to have a boosted sled that is just turn key finally!