Technical Discussion Topics related to Technical Issues

I got problems!

Thread Tools
 
Search this Thread
 
Old Jul 25, 2007 | 08:52 PM
  #1  
autoteach's Avatar
Thread Starter
Senior Member
SuperBike
 
Joined: Mar 2007
Posts: 1,611
From: Belgium, WI
autoteach is on a distinguished road
I got problems!

So, it doesn't concern me greatly, but... After doing my undertail exhaust, I have been having what appears like a rich (or ignition misfire) stumble on hard throttle at 6500rpms. Why I say its rich is that the dyno sheet shows a remarkable drop in power and a dip in air fuel ratio. My question is if anyone else has had this problem???

I have run through the scenarios in my head, coil would continue to suck ***, same with spark plugs. I just can't think of a possible solution as of right now, that doesn't cost me of course.
Old Jul 26, 2007 | 11:18 AM
  #2  
RPV-Hawk's Avatar
Senior Member
Superstock
 
Joined: Sep 2006
Posts: 308
RPV-Hawk is on a distinguished road
Post Dyno with A/F curve?
17/43 gearing?
Old Jul 26, 2007 | 06:34 PM
  #3  
SuperHawkins's Avatar
Senior Member
Back Marker
 
Joined: Dec 2006
Posts: 247
From: Palm Bay, FL
SuperHawkins is on a distinguished road
6500 is a strange place to have a hiccup.... I see you have a drop-in.....stock airbox? Don't see why you'd have a rich dip at that particular rpm though there's something funny going on in the airbox like it's losing pressure
Old Jul 26, 2007 | 07:18 PM
  #4  
Hawkrider's Avatar
Administrator
World Champion
 
Joined: Dec 2004
Posts: 105,287
From: Fulton, MO
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
The airbox isn't pressurized.

6500 is when the mains start playing into the jetting equation. It's mainly the needle height and profile though. Maybe drop the needles a bit?
Old Jul 26, 2007 | 10:30 PM
  #5  
Thumper's Avatar
Senior Member
SuperBike
 
Joined: Jul 2004
Posts: 1,015
Thumper is an unknown quantity at this point
Originally Posted by Hawkrider
The airbox isn't pressurized.

6500 is when the mains start playing into the jetting equation. It's mainly the needle height and profile though. Maybe drop the needles a bit?
+1
Old Jul 27, 2007 | 05:01 PM
  #6  
autoteach's Avatar
Thread Starter
Senior Member
SuperBike
 
Joined: Mar 2007
Posts: 1,611
From: Belgium, WI
autoteach is on a distinguished road
I know what you are thinking, 17/43 gearin???? Yeah, so I could only get the sidewinder tri-metal in a 43 tooth and didn't want to loose the highway attitude so I bumped up the front a tooth. The ratio is a tidbit shorter, but hardly noticeable. Less wheelie happy, for sure. I shoulda done a 520. Oh well,
As for the jetting. Ok on the needles coming in at the point, but the problem is that we have it dialed in right no for AFR and don't want to dick with it. I just didn't know if anyone had experienced this problem. Also, i have a goofy undertail I built myself, so I think that may be part of the problem.
thanks,
Bill
Old Jul 29, 2007 | 04:16 PM
  #7  
Hawkrider's Avatar
Administrator
World Champion
 
Joined: Dec 2004
Posts: 105,287
From: Fulton, MO
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
How would the undertail have anything to do with the jettting? I'm cornfused!
Old Jul 30, 2007 | 03:28 PM
  #8  
autoteach's Avatar
Thread Starter
Senior Member
SuperBike
 
Joined: Mar 2007
Posts: 1,611
From: Belgium, WI
autoteach is on a distinguished road
the lengths of the exhaust will play a role in the wave tuning and could definitely cause hiccups in a carbed bike. Oh well, I think I am going to just keep beating it like a bad dog.
Old Jul 30, 2007 | 04:13 PM
  #9  
Hawkrider's Avatar
Administrator
World Champion
 
Joined: Dec 2004
Posts: 105,287
From: Fulton, MO
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
Aha! Undertail EXHAUST! Got it. I was thinking undertail, as in fairing.
Old Sep 12, 2007 | 11:43 AM
  #10  
autoteach's Avatar
Thread Starter
Senior Member
SuperBike
 
Joined: Mar 2007
Posts: 1,611
From: Belgium, WI
autoteach is on a distinguished road
Thought that this may shed some light on recent tuning questions. I lost one of my homemade endcaps to my homemade exhaust. This pretty much sucks, but the shop i was working at had a shifter cart exhaust end that would work with my diameter, yeaaaaah. But wait, it only had a 1" outlet, so I tried it and it completely fixed all my carb problems. The first time I went out I hit the rev limiter in first because it didn't hiccup at 6500 and lose power. NOT ENOUGH BACK PRESSURE, i say, so its getting equal sized outputs to help this, and quiet the bike overall. Boy I am happy.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Yardstick
General Discussion
32
May 14, 2008 07:35 AM
SuperHawkins
Technical Discussion
27
Jul 31, 2007 09:34 AM
igeorgei
Technical Discussion
5
Apr 17, 2007 08:07 PM
mkimber
Modifications - Performance
10
Mar 30, 2007 05:49 PM
klicks
Technical Discussion
3
Mar 13, 2007 04:26 PM




All times are GMT -7. The time now is 06:37 AM.


Top

© 2026 MH Sub I, LLC dba Internet Brands



When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.