spray25
TY 4 Stroke God
have you pulled the plugs to confirm the reading you are getting on the a/f gauge?
I have been running rich and it shows. They have been dark and sometimes black. Seeing readings of 10-11.
For the first time I have seen 12.5 constant was Sunday. I changed out the charge tube jet from a 500 to a 700. I ran it out from ideal to wot back to ideal then to wot and shut it down, pulled the plugs and they cleaned right up and looked good. Then on the way back to the garage I blew the intercooler off the carbs. (then broke the clip and now waiting for parts).
So I think I am getting it! We will see when I get the carb parts in.
For the first time I have seen 12.5 constant was Sunday. I changed out the charge tube jet from a 500 to a 700. I ran it out from ideal to wot back to ideal then to wot and shut it down, pulled the plugs and they cleaned right up and looked good. Then on the way back to the garage I blew the intercooler off the carbs. (then broke the clip and now waiting for parts).
So I think I am getting it! We will see when I get the carb parts in.
spray25
TY 4 Stroke God
Checking the plugs is something I was suggesting to the OP. It might help him decide if the new placement of his o2 sensor is the problem or if he truely is lean in the midrange.
BigDog05
VIP Member
Spray25: I didn't check the plugs until I got home. They were a little on the rich side, but my last run was aprrox 1000-1200 ft at WOT, at 6 lbs and a 600 in the pitot.
Last season I could run 10lbs with a 600 and be right at 11.7-11.8 at WOT.
12 lbs with a 500 in the pitot.
Conditions were so bad on Sunday that we only put about 35 mi on, so everytime it would start to run lean I would just grab some throttle and as soon as it spooled it would be a little rich with the 600.
We are geting snow up the mountains right now. To me 2900 ft is a mountain.
Tomorrow I'm going to put some 103 unleaded in it and get the WOT to
where it was last year.
Were I ride there is a 6 mile joint use road that if the conditions are good you can cruise 55-70 MPH easily.
Once I get the boost dialed in, then I'll start pulling plugs in the midrange.
Ted: My new quiet muffler is like the Camaros used to be. One inlet on the left side and two outlets out in the stock locations. So you don't actually have 18" of pipe. That is why I was thinking bad readings. I ran the sled on an engine hoist with the old exhaust and sensor in front of the turbo, and in the new location about 15 minutes apart the day I put the new muffler on. Reading from idle to 60MPH track speeds where the same at every 5 mph increase.
That is why I was thinking with the sled moving and and only light throttle that I'm possibly getting some sort of reversion in the muffler.
Thanks guys
Last season I could run 10lbs with a 600 and be right at 11.7-11.8 at WOT.
12 lbs with a 500 in the pitot.
Conditions were so bad on Sunday that we only put about 35 mi on, so everytime it would start to run lean I would just grab some throttle and as soon as it spooled it would be a little rich with the 600.
We are geting snow up the mountains right now. To me 2900 ft is a mountain.
Tomorrow I'm going to put some 103 unleaded in it and get the WOT to
where it was last year.
Were I ride there is a 6 mile joint use road that if the conditions are good you can cruise 55-70 MPH easily.
Once I get the boost dialed in, then I'll start pulling plugs in the midrange.
Ted: My new quiet muffler is like the Camaros used to be. One inlet on the left side and two outlets out in the stock locations. So you don't actually have 18" of pipe. That is why I was thinking bad readings. I ran the sled on an engine hoist with the old exhaust and sensor in front of the turbo, and in the new location about 15 minutes apart the day I put the new muffler on. Reading from idle to 60MPH track speeds where the same at every 5 mph increase.
That is why I was thinking with the sled moving and and only light throttle that I'm possibly getting some sort of reversion in the muffler.
Thanks guys
BigDog, have you figured out your problem?
Run it right at the lean spot, shut it down and pull the plugs. That should tell you weather its lean or not. If the plugs are fine put the sensor back....that is the first step I would do IMO.
By the way..everyone said 500 or 600 on the charge tube jet. I am at a 700 and stock carbs. Seeing wot readings around 11.5-12 at 11lbs of boost
Run it right at the lean spot, shut it down and pull the plugs. That should tell you weather its lean or not. If the plugs are fine put the sensor back....that is the first step I would do IMO.
By the way..everyone said 500 or 600 on the charge tube jet. I am at a 700 and stock carbs. Seeing wot readings around 11.5-12 at 11lbs of boost
BigDog05
VIP Member
FAMILYMAN: Pulled the intercooler and checked all connections etc. I watched everything really close while I was taking it apart and everything seemed fine. Nothing looked out of order.
While I was doing that I changed the springs back to stock just to get it closer to the way it was last year. I don't think that will do anything.
Problems at work today, so I probably won't make it to the mountains until Friday. It is finally snowing though. Calling for 5-7 inches by Friday in the mountains.
I plan on doing what you suggested.
The thing that confuses me the most is it feels great.
While I was doing that I changed the springs back to stock just to get it closer to the way it was last year. I don't think that will do anything.
Problems at work today, so I probably won't make it to the mountains until Friday. It is finally snowing though. Calling for 5-7 inches by Friday in the mountains.
I plan on doing what you suggested.
The thing that confuses me the most is it feels great.
rxrider
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BigDog05 - What did you do to correct your lean spot?
woodsrider
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In answer to the guy that suggested you not use the petit tube jet, IMO that is one of the features that sets the Bender unit apart from the others. It allows you to make fine tuning adjustments (do to temp, altitude) in a matter of seconds. I guess if you ride at a constant elevation then it may notbe as critical. In the west you can have a 4,000-ft elevation change very easily from where you unload to where you ride.
BigDog05
VIP Member
rxrider: I never did get rid of it. I'm running the same jetting as you except I have my needles one notch rich.
I'll be cruising along at 55-70mph under very low boost or no boost and I'll hit a 16- 17.5 or so reading. Never any problems at 3 or more pounds of boost. I have stopped and pulled the plugs at least 10 times and they look great. If anything a little rich for unleaded gas.
I can get rid of it by moving the throttle a 1/16 of an inch up or down.
I think I'm going to try a different A/F guage this year. I have an Innovative. Ever since I put that guage on I have been wrestling with idle and no boost jetting.
When I originally put the guage on I was running 17.5 pilots at 2 turns and had a reading of 16.7-17.2 or so at idle. Went to 20 pilots at 2 turns and it was reading 14.4-15.7 or so depending how cold the engine was.
This was all in the driveway at around 950 ft elevation.
Two weeks later and I'd start the sled to put it and the trailer and I'd be getting readings of 13-14 depending on engine temp.
I have since gone back to the 17.5 pilots at 2 turns.
The last day I rode was 3/8/07. At home that morning it was 27F and my idle was 16.5-17.2. I had just put the 17.5 pilots back in the night before.
Got to the mountains and it was about 21F at 2200-2900 ft elevation.
Sled was idling at 14.2- 15.2 all day. Got it home that evening and when unloading around dark it was about 27F again. The sled was idling around 14.5-15.5.
Started the sled last week and ran on the stand, and it was 14-14.5 at about 45F.
I'm going to try an AEM guage this year.
I was running a mix of 110 sunoco racing and 93 unleaded last year. This year I ran a mix of 93 unleaded and VP 103 unleaded race gas. I have two sensors and both were free air calibrated numerous times. One sensor has never seen lead.
I'll be cruising along at 55-70mph under very low boost or no boost and I'll hit a 16- 17.5 or so reading. Never any problems at 3 or more pounds of boost. I have stopped and pulled the plugs at least 10 times and they look great. If anything a little rich for unleaded gas.
I can get rid of it by moving the throttle a 1/16 of an inch up or down.
I think I'm going to try a different A/F guage this year. I have an Innovative. Ever since I put that guage on I have been wrestling with idle and no boost jetting.
When I originally put the guage on I was running 17.5 pilots at 2 turns and had a reading of 16.7-17.2 or so at idle. Went to 20 pilots at 2 turns and it was reading 14.4-15.7 or so depending how cold the engine was.
This was all in the driveway at around 950 ft elevation.
Two weeks later and I'd start the sled to put it and the trailer and I'd be getting readings of 13-14 depending on engine temp.
I have since gone back to the 17.5 pilots at 2 turns.
The last day I rode was 3/8/07. At home that morning it was 27F and my idle was 16.5-17.2. I had just put the 17.5 pilots back in the night before.
Got to the mountains and it was about 21F at 2200-2900 ft elevation.
Sled was idling at 14.2- 15.2 all day. Got it home that evening and when unloading around dark it was about 27F again. The sled was idling around 14.5-15.5.
Started the sled last week and ran on the stand, and it was 14-14.5 at about 45F.
I'm going to try an AEM guage this year.
I was running a mix of 110 sunoco racing and 93 unleaded last year. This year I ran a mix of 93 unleaded and VP 103 unleaded race gas. I have two sensors and both were free air calibrated numerous times. One sensor has never seen lead.
woodsrider
TY 4 Stroke Junkie
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Here's my 2-cents worth. Verify your AFR readings by checking your plugs. If that checks out raise your needle jet (lower the clip) if that helps but you cann't quite get to where you want to be change to a richer needle jet (not sure if one is available thru aftermarket or not) and start in the middle clip position on the new needle jet. Keep adjusting as req'd. If there is not an after market needle try using the Mikuni nylon spacers (washers) under the clip. This will raise the needle about half a clip position per spacer.
