|09-27-2013, 09:15 PM||#1|
Joined: Sep 2006
950SE CPR Rottweiler Jetting problem
I am having a problem with my 08 950se and wondering anyone has any insight. I had a 2 into 1 exhaust system with original airbox and wanted a bit more performance. So went back to a 2 into 2 with a new set of wings and put on a CPR Rottweiler intake system on as well as the cj racer / adv machines jetting kit.
Wings 2into 2, w decibel killers.
Adv machines CPR jetting kit
Air Screws, 2 1/2 turns out.
Floats, 3 mm ish
Needles, 3 position
The problem is that it's very lean with lots of popping off idle as well as deceleration. It's also hard to start. The basics are done, carbs clean, seated properly, etc. So I am thinking the floats, but is there anything else that it could be?
|09-27-2013, 10:07 PM||#3|
will work for tires
Joined: Sep 2011
Location: KC, KS... flat&boringville
When I installed this system on my SE (CPR w/ 2 into 1), my original starting point was much like yours. After some tweaking, I've found another setup that works better for the 1000' elevation I'm at & gives better mileage too. To be fair, this "find" was through the help of several inmates on here. I'm no expert... just sharing my experiences. YMMV.
I'd be willing to bet you are not lean w/ that jetting, unless that 2into2 exhaust is flowing a ton more air than most. Those are pretty salty numbers. I would recommend to go leaner.
Do you have any intake manifold caps, bolts, sas plates, etc. possibly leaking? Cracked vacuum cap anywhere? Double check all spots, cc breather hole, hose, etc.
1.) Lean floats to exactly 4mm... exactly!
2.) 50 (stock) IAJ's. Get the 60, 65, or 70's out of there
3.) Play w/ position #2 & #3 on needles (FP needles, I assume)
4.) Come down on your mains 5ish %
5.) 42 Pilots if above 5000' consistently
6.) 2-3 out on IMS
#1 & #2 helped my bottom end & partial throttle smoothness. Leaning out the top end, it seems happier. I have no AFR data to prove it, but others do. It rips. Only the stupid in me wants for more. Needle & IMS settings are so bike specific, so just tinker with those settings. Be picky.
Search HERE for lots if jetting experiences & examples.
Tinker away & you'll find it. How 'bout that carb access, eh! Have fun.
"Never let the things you want make you forget the things you have"
|09-27-2013, 11:07 PM||#4|
Joined: Jul 2004
Location: Pickwick Lake, Tennessippi
+1. I've had nearly exactly the same experience as JRod. I'm running one of the original 2-1 prototype collectors with a 2.5" core muffler. IMHO, assuming your are running the FP needles, my bike is happiest with the floats at 4mm. Take the time to get them right, when running the air box free environment LC8.
gaspipe [the original]
Hair of the dog....
|09-28-2013, 05:05 AM||#5|
Joined: Apr 2007
Location: West Des Moines, IA
FWIW, I have a pretty stock carb setup on my 950 ADV and could not get the bike to run the passes in Colorado. The floats were off when we checked, but the solution was to move the floats to 4mm. Even with the floats at 4 and otherwise stock setup with 160/165 mains, we had to fully close my FlexJets to make the bike run at the high passes. When I came back down to 900' elevation, I just opened the Flex Jets up to a pretty standard 2.5 turns out, and the bike runs great.
I would definitely recommend moving your floats up to 4mm and then work from there to find the a mix that works well for your bike.
"I'd like to meet the joker who had the nerve to call this a road!" -- Walter Sigmann
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|09-28-2013, 09:19 PM||#6|
Joined: Sep 2006
Thanks for the replies. A few things I forgot to mention I am at sea level and I have looked through multiple forums about jetting. It seems that changing the idle air jets back to the stock 50's is the general consensus which would narrow the idle air circuit. Also going to 4 mm float height has a few supporters as well. The only problem I have with rising the float levels is that it also seems that there is a fuel starvation issue with the hard starting. So won't raising the floats worsen the fuel issue?
|09-28-2013, 09:52 PM||#7|
Trusting my Cape...
Joined: Mar 2006
Location: Where the hell is Truckee, CA?
First of all, you say the air screws are set at 2 1/2 turns. These are actually FUEL screws, not air. so more turns out means MORE FUEL and less turns means less fuel. Using these, and the choke (which is also a fuel/richening circuit), you can experiment to see if you are rich or lean at start-up/low rpm.
Run the screws at 5 turns out and 1 turn out. If the bike prefers 5 turns, then it is currently lean and vice-versa. What about the choke? If it starts better with FULL choke regardless of temp, you are lean at start-up. Knowing this, you can then decide which way to go with other jetting.
07 Yamaha R6
07 KTM 950 Super Enduro
04 KTM 250exc- plated two-stroke
01 Kawasaki KE100
74 Honda MR50
|09-28-2013, 11:21 PM||#8|
Joined: Feb 2010
Location: ESCONDIDO, CA
I don't run a rottweiler setup but similar.
Here's my setup for reference:
2008 950SE runs perfect at sea level with my aluminum plate and itg jc30/65s sausage style air filter, slightly butchered carb intake bells and the following carb settings:
stock pilot jets (42)
stock air jets (50)
floats at 4mm
factory pro needles with clip at 2nd position from top
2 turns out on fuel screws
I rode to big bear (7000 feet elevation) and had to turn fuel screws in 1 turn..... (Easy with the extensions)
I checked spark plugs after about 1000 to 1500 miles of running with the above setup and they looked brand new. So I think if anything, I may be running on the lean side. I can probably go up to 178 or 180 main jets. But the thing is I will possibly be too rich if I climb to 10000 feet or so... I am going to leave it alone. I get 36 mpg avg.
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