Well I've had an existing problem with my sled for awhile now and have tried everything I can think of short of taking it to the dealer (where it's going on Mon). Starts great, idles great, at wot it's good (not pulling max rpm's but thats a clutching issue separate that I've got parts coming for) and as long as i don't try and hold a steady speed it's fine, like on and off the throttle. The problem comes when I try to maintain a steady speed anywhere around half throttle. After about half a mile it almost sounds like it starts running on one cylinder and turns into a big piece of chit. EGT's will fall about 200 degrees cooler on one side than the other. If I stop let the cylinders balance out or shut it off and restart it away you go again until you try and hold it at a steady speed. Checked all the obvious like power valves, wiring etc. and nothing. When it fires on both it has loads of power but that doesn't happen very often. Sled specs are 2005 M7 with a speedwerx 800 big bore, speedwerx pipe, v-force reeds, the thing can, sno pro intake, and boondocker. I have a feeling its fuel related but not familiar enough with the box to know where to take/add fuel. Anybody have any ideas before it goes to dealer?? Sorry for the long post and thanx
Almost had enough of my M7!!!!!
- Thread starter blackt
- Start date
try putting your stock can back on. I know of a m7 and a m1000 that would run like crap right around were the exhaust valves open up. Changed the can and it would run fine.
maybe your mid range is a lil fat?? try droping a few numbers in your boondocker in the 5000, 6700 rpm settings, and remember 3 numbers is one jet size... see if that helps
Last edited:
Maybe a stupid question but, have you checked the reeds? What about a fuel pressure regulator. I read on here alot that with certain pipe combo's if you don't have the fuel pressure set the same as what the parts were tested at that it can affect how the engine responds to said modifications. Some say that a fuel pressure regulator is not the tool too use when tuning, but no two fuel pressures will be the same, I know this because it's like hydraulics, out of the box every pump is a little different I don't care what kind of pump it is. Why do you see pressure regulators on drag car nitrous set ups...................? So, a regulator is good, I feel to establish a base line pressure. I'm no rocket scientist but having consistent pressure makes sense.
Last edited:
To help KMMAC out a bit, remember guys that he has one side that drops 200 degrees while the other maintains proper temperature.........
Funny you have this issue, I have been battling this problem for a while on my modded Yamaha Banshee.....bought complete electrical system, rebuilt the engine, and several other tries to never get it to run for an extended period on both cylinders.
Funny you have this issue, I have been battling this problem for a while on my modded Yamaha Banshee.....bought complete electrical system, rebuilt the engine, and several other tries to never get it to run for an extended period on both cylinders.
does the m7 have a det sensor...??..if ya holding throttle steady and not varing it at all...is the det sensor kicking in to save burndown on one cyl..etc..limp mode.....my m8 has det sensor...and i know stock there was l lean area if held steady that i know it would activate the det sensor but i always just feathered threw that rpm range...approx 5500
Wow thanx for all the quick responses. I'll try and answer all the questions so we can keep this going. G Force you asked about my temps at a steady rpm of anywhere from 5500 to 6800 they will hover around 900-1000, they don't get much higher because it starts fartin around before it can run long enough to heat it up. Kittycat I am on the same page as you I think it's a fuel issue but like I said not up to snuff on my knowledge with the boondocker to start doing a whole bunch of messing around, that and I'm fed up after fighting with it for this long. Treebender did you ever figure the issue out on your banshee or is the problem still exist???? Thanx again for everyones responses. Hopefully with the new info I gave we can come up with some other ideas.
Thanx for all the responses. To answer a few of the questions the rpm range that it craps out in is anywhere from 5000-6800 temps nver get above 1000 just because it doesn't run good enough for long enough to get them up. Personally i think its a fuel issue but I don't have the know how to play wit my boondocker confidently. I wanna get the thing running good so anybody can get on it and ride and doesn't have to worry about the egt's (my wife doesn't know what egt's are for so explaining it would be harder than getting it running right).The 05-06 M7's don't have a det sensor. It's seems ok as long as I'm on and off the throttle burping it from half to wot pulls but just for short bursts at wot. To hold it wot it won't act up just doesn't rev right up to 8000 only about 7300 but thats to do with my weights. Held it on a lake for 2 miles and never burped or anything my egt's stayed around 1080-1125 in that area but never climbed.
What do the plugs look like after it happens? Which side is sputtering, PTO or MAG? I've had my fair share of boondocker headaches and this sounds like something I may have had issues with on a previous sled.
Plugs are a tad on the rich side but not slobbering wet. Problem is on the mag side just about everytime once i think it happened on the pto.
First thing, make sure your boondocker connections at the injectors are good. Could be some harmonic vibration happening at those RPM's causing them to loose their solid connection. Try some dielectric grease on the connections.
You can add or take fuel from one cylinder at a time, I'd say it is loading up and running to rich. Your egts numbers are pretty conservative going off of you sayingt the plugs look on the rich side. Take some fuel away at the rpm its cutting out at. most sleds when you run under 6100 before the power valves open will run pretty hot on the egts. When the P/V are closed the extra fuel can't get out and fouls the plug, thus the need for higher temps in that range to burn off the extra fuel. On the bd box there is a setting in each rpm range called (tr) for trim what it does is it takes or adds fuel on the mags side only (I think its the mag side any way), so if your dropping the mag cylinder, at what ever rpm its dropping set the tr at -3 and see how it does. do you have a single or dual egt.
You don't need a regulator with a bd box, it does everything you need
You don't need a regulator with a bd box, it does everything you need
Last edited:
What are your BD #'s blackt? Sounds like it may be rich. Your 05 was a fairly rich stock map, assuming you never had it re-flashed? I would start pulling fuel on the 5000 and 6800 range on the low and med ranges first, and watch your temps/plugs, I would leave the hi setting in those ranges alone, but that's me. I think the trim function works on either cylinder, no? That's more of a fine tune deal for twins and or NOS from what I can gather.
G.
G.
i used to have an old ext 580 efi that did the same thing you are talking about. it ended up being the throttle position sensor. in saying that, i now have a 06 m6 that does this from time to time exactly as you describe. but i dont have to shut mine down to get it to clear up. i feather the throttle and away it goes. mine is totally stock. either i am running rich there and it starts to foul a plug or i am loosing spark for a moment, i dont know but like you said i know how to live with and ride it accordingly. hope you find the answer.
did it start doing it after a certain time period? how about stock? can you put on the stock can?
clarence
did it start doing it after a certain time period? how about stock? can you put on the stock can?
clarence
Sounds rich to me
Or possibly an injector problem?
On my 06 M7, midrange temps could get pretty high,1050-1150 being pretty normal. But, if you ran it richer, you lost a lot of mid range snap and throttle response, especially when getting off the trail and playing in the powder.
I would try taking away a few #s in the mid and definitely double check all connections
Or possibly an injector problem?
On my 06 M7, midrange temps could get pretty high,1050-1150 being pretty normal. But, if you ran it richer, you lost a lot of mid range snap and throttle response, especially when getting off the trail and playing in the powder.
I would try taking away a few #s in the mid and definitely double check all connections
Agree with the low/mid setting, I'm pretty sure its just the mag sid it tells you in the directions.
Last edited:
My #'s from speedwerx are as follows 3000 0-0-0-0, 5000 3-0-0-0, 6700 10-0-0-0, 7800 0-2-9-0, 8100 0-2-9-0. From these #'s I went 3 #'s above their settings so at 5000 I went 6-0-0-0 etc. So I know I may be a bit rich but I didn't think I was that bad. I have been reflashed to an 06 ecu sorry never mentioned that. The reason I went above the speewrx #'s is just to be safe but in your guy's opinion am I running high compared to similar sleds??? So if I do need to pull some fuel away from the midrange is it possible to tune this sled so that my wife can ride it if she needs to and not have to worry about my egt's if she's cruising along dumdeedum at 6000 rpm??? (you know how wives sometimes ride they can't grasp the thought of burping the throttle, she can ride but sometimes the simple things can confuse her) thanx again for the help.
Last edited:
#s definitely seem rich
My 06 M7 with Speedwerx single, Thing can, STM valves and RKT head at around 8-9k
Can't remember exact #s but,
my 6700 #s were only like plus 2 or so and 5000 was plus 3 or 4
I believe I was at -8 or -10 at 7800 and 8100 RPM
I would think +13 might cause a problem
My EGTs were in the 1050-1150 in the midrange. 1225-1275 on a long, very long pull in deep powder. Plugs always looked good. Despite this, I still ran out of gas at 58 miles once
When I put the stock head on, wash was spot on
My 06 M7 with Speedwerx single, Thing can, STM valves and RKT head at around 8-9k
Can't remember exact #s but,
my 6700 #s were only like plus 2 or so and 5000 was plus 3 or 4
I believe I was at -8 or -10 at 7800 and 8100 RPM
I would think +13 might cause a problem
My EGTs were in the 1050-1150 in the midrange. 1225-1275 on a long, very long pull in deep powder. Plugs always looked good. Despite this, I still ran out of gas at 58 miles once
When I put the stock head on, wash was spot on
Last edited:
Glennrmk thank you soo much I have never been able to find anybody with any actual #'s to compare too. Keep in mind I am running a big bore 800 so I'll need a bit more fuel than you but yeah if you were running -8 on the top end and I'm at +13 thats a huge difference, like almost 7 jet sizes if 3 #'s equals one jet. I'll do some digging tomorrow as well one fellow here posted he reran the clear tube from straight down to back towards the gas tank and his bog he'd been fighting for the last year dissappeared. That said mine is running straight down as well, at this point I'll try anything. Thank you.
