New Brainbox Question

buck1974 · 02-21-2010, 11:48 AM

I have 2008 Mastiff, just had the brain box replaced under warranty. Before it went out, I had a Andrews 612 cam and S&S dual runner installed. Then the bike was dyno'ed and tuned, the bike ran great. However, now I had the new brain box installed, I have decel pop extremely bad, more than I have ever had. Let off the gas and its just continuous poping and backfiring. Need help, what could be causing this? Just replaced brain box, I thought?

BBChopper · 02-21-2010, 01:02 PM

Carb mixture!!! Do a search or go to the "How TO" page.

Here,
How to adjust your carb and check jetting

woodbutcher · 02-21-2010, 01:06 PM

make sure the pipes are properly seated to the heads with new gaskets.

BBChopper · 02-21-2010, 01:12 PM

Quote:

Originally Posted by woodbutcher

make sure the pipes are properly seated to the heads with new gaskets.

True Wood, always good to get the "pipe to the head" right!!

Trainguy · 02-21-2010, 01:45 PM

With that much cam on a 2008 engine did you do a spring change (beehive style) or check for clearances?

1mndg · 02-21-2010, 04:09 PM

Check for air leaks, both exhaust and intake will cause this problem.

mobsta · 02-21-2010, 04:16 PM

the carb adjustment sounds the most logical as bb said,however if the dealer changed out the ehc i would call them and see what else they did or didnt do since it was all good before the change but thats just me.good luck and keep us informed

buck1974 · 02-22-2010, 02:27 AM

Thanks for all the response just getting back into the site. I will call the dealership, I will check the exhaust, but the exhaust was not touched so I would think that should be good. The carb is what I will talk to the dealership about. They may have tooled around with it while it was there. I did notice since I had my bike I have never used the enrichiner ( choke ), however when I picked it up it wouldn't start and stay running unless it was pulled out until warm. That is how they started it. This is the same dealer I purchased the bike from. When I bought it they told me the choke was the last resort, keep from using it if you can. It can foul the plugs easily, but they were quick to use it this time after the I went to pick it up when the brain box was replaced I will call Tuesday and find out what they did Thanks.

02-21-2010, 11:48 AM	#1 (permalink)
buck1974 Buck Name: Buck Join Date: Apr 2009 Location: Smiths, Alabama Posts: 35 My Bike(s): 08 Mastiff My Biker Photos Rep Power: 0	New Brainbox Question I have 2008 Mastiff, just had the brain box replaced under warranty. Before it went out, I had a Andrews 612 cam and S&S dual runner installed. Then the bike was dyno'ed and tuned, the bike ran great. However, now I had the new brain box installed, I have decel pop extremely bad, more than I have ever had. Let off the gas and its just continuous poping and backfiring. Need help, what could be causing this? Just replaced brain box, I thought?

02-21-2010, 01:02 PM	#2 (permalink)
BBChopper "Ferrum Vir" Name: Pablo Join Date: Nov 2007 Location: South Florida, Posts: 10,552 My Bike(s): 2005 BDM Choppa, 1996 Ultra Classic My Biker Photos Rep Power: 10	Carb mixture!!! Do a search or go to the "How TO" page. Here, How to adjust your carb and check jetting __________________ *Smart Azz White Boy!!!* http://www.badassbikeseats.com/ http://lowdownchopshop.com/

02-21-2010, 01:06 PM	#3 (permalink)
woodbutcher Senior Member Name: Tom Join Date: Aug 2007 Location: hilton head is., sc Posts: 3,643 My Bike(s): '07 K9 My Biker Photos Rep Power: 6	make sure the pipes are properly seated to the heads with new gaskets. __________________ the man with a hell of alot to say generally doesn't have a hell of alot to say. narow's dad "DEATH SMILES AT ALL OF US---ALL I CAN DO IS SMILE BACK" -- Al "Alicat" Sensoli RIP

02-21-2010, 01:45 PM	#5 (permalink)
Trainguy Chromeoholic Name: DJ Join Date: May 2009 Location: Between Hell & Detroit Posts: 1,406 My Bike(s): K9 Karata 4" OP, V&H 2-1 S&S air+585, xo grips&pegs K&P oil & duel coolers, Ness, all chrome w/blk My Biker Photos Rep Power: 2	With that much cam on a 2008 engine did you do a spring change (beehive style) or check for clearances? __________________ It ain't a party till the cops show up.

02-21-2010, 04:09 PM	#6 (permalink)
1mndg RIDE IT HARD!!! Name: Bob Join Date: Jun 2008 Location: Pottsville, Pa. Posts: 466 My Bike(s): 2004 Chopper DT My Biker Photos Rep Power: 3	Check for air leaks, both exhaust and intake will cause this problem. __________________ It's 5:00 o'clock somewhere!!!

02-21-2010, 04:16 PM	#7 (permalink)
mobsta Member Name: joe Join Date: May 2009 Posts: 1,892 My Bike(s): O4 MASSTIFF My Biker Photos Rep Power: 3	the carb adjustment sounds the most logical as bb said,however if the dealer changed out the ehc i would call them and see what else they did or didnt do since it was all good before the change but thats just me.good luck and keep us informed

02-22-2010, 02:27 AM	#8 (permalink)
buck1974 Buck Name: Buck Join Date: Apr 2009 Location: Smiths, Alabama Posts: 35 My Bike(s): 08 Mastiff My Biker Photos Rep Power: 0	Thanks for all the response just getting back into the site. I will call the dealership, I will check the exhaust, but the exhaust was not touched so I would think that should be good. The carb is what I will talk to the dealership about. They may have tooled around with it while it was there. I did notice since I had my bike I have never used the enrichiner ( choke ), however when I picked it up it wouldn't start and stay running unless it was pulled out until warm. That is how they started it. This is the same dealer I purchased the bike from. When I bought it they told me the choke was the last resort, keep from using it if you can. It can foul the plugs easily, but they were quick to use it this time after the I went to pick it up when the brain box was replaced I will call Tuesday and find out what they did Thanks.

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