bad lifter?
Seasoned HDF Member
Joined: Aug 2007
Posts: 8,192
Likes: 3,079
From: NW AR
Any inputs helps... and appreciate the feedback. My backfiring is consistent at least. When under load there is seldom a pop but when I down shift or let off the throttle thats when I'll get a series of pops, almost like my old carburated 76 Superglide. I checked my wires like you said. And of course inspected the plugs. I thought if the base ring on the plug looked like I was running rich, maybe that was my issue. But why all the sudden? Just thinking out loud now. I suppose I would want to check timing before trying to recall how I set up that PCIII when I installed it several years back. Thanks for the ideas.
Road Captain
Joined: Apr 2005
Posts: 535
Likes: 14
From: Highspire Pa
After making absolutely sure I did not have any air leaks, I found just running the idle mixture a little richer cured most of the popping out the exhaust on deceleration.
The Mikuni tuning guide provides some interesting information titled "backfires in the exhaust"
http://www.mikuni.com/fs-tuning_guide.html
The Mikuni tuning guide provides some interesting information titled "backfires in the exhaust"
http://www.mikuni.com/fs-tuning_guide.html
6th Gear
Joined: Nov 2007
Posts: 12
Likes: 0
From: Split time between OKC & Northern Idaho
Bad Lifter
Thanks Doc, Pajoe, I've got sampson true duels (with K&N a/c and PCIII) & I've listened and looked for leaks but not as careful as I could. I'm assuming I'll have some residue for principal clue. Also, will chech my manual for adjustments. Mine is FI and not sure if I have that option but will find out from the manual. Appreciate it.
Outstanding HDF Member
Joined: Mar 2010
Posts: 2,877
Likes: 2
From: Hallsville, Tx.
Not much you can do for EFI tuning without getting an after market tuner of some knid. I have a Revtech DFO that I got from J&P for about 100 bux. You may want to consider that if you want do do any exhaust or intake mods. The DFO overides the ECM to allow more fuel. It has pot adjustments for idle, accelerator pump, main "jet" etc, so it's tuneable.
Outstanding HDF Member
Joined: Aug 2010
Posts: 3,486
Likes: 6
From: Union,Ms
Not much you can do for EFI tuning without getting an after market tuner of some knid. I have a Revtech DFO that I got from J&P for about 100 bux. You may want to consider that if you want do do any exhaust or intake mods. The DFO overides the ECM to allow more fuel. It has pot adjustments for idle, accelerator pump, main "jet" etc, so it's tuneable.
Outstanding HDF Member
Joined: Mar 2010
Posts: 2,877
Likes: 2
From: Hallsville, Tx.
There are several variations, all based on or rebadged Doebeck tuners.
Intermediate
Joined: Nov 2009
Posts: 44
Likes: 1
See if anyone can help me. I got a valve noise that comes and goes. The shop did the lifters and rods. The noise has change a little but still comes and goes but not as often. It is not the normal sewing machine but is in time with it. Could it by aother bad set of lifters? It does sound like it is coming from the upper end. Is there anything that could be in the upper end that can make noise that comes and goes? Is there anything that could be bouncing around??
Intermediate
Joined: Nov 2009
Posts: 44
Likes: 1
I look and all pipes are good. THe bike has to be warm for the noise. Has anyone heard of a valve guide bouning up and down on a valve? I have no power loss, no smoke... It got me and the guy at the shop.
It does happen right after I run it up to highway speed.
It does happen right after I run it up to highway speed.
