Plugs are different color?
- Thread starter Zenman
- Start date
Keep in mind with a V twin the front cylinder will run a little cooler then the rear, I've had 4 different HD/BDM over the last 25 years and all showed the front plug running a little richer. If it runs Ok I always left it alone also I always prefered my motors to run a little rich then lean. Post some photos of the plugs and jet the carb to get the rear plug the way you want it and if the front is a little rich, I would not worry about it if you not having any problems.
Thumper169
Well-Known Member
This is very true,:up:
Staffy
Active Member
Acceptable - IF the bike runs well and feels good.
The rear cylinder running lean is "normal" - a few of us can attest to that (including me). I have always kept an eye out for that and used to go crazy trying to figure it out – until I found the same symptoms on “all” my Vtwin bikes. In fact was reading an interesting post (see link below) and looking at the pic’s of the cylinder heads – You see what I see? There you have it – so don’t go crazy if the bike if running fine.
http://www.bigdogbiker.com/forums/dog-pound/10583-winter-projects.html
(PS. I did actually have an intake leak on one of my bikes a few years ago – if I remember correctly the rear cylinder ran EXTREMLY hot (RED GLOWING HOT) at the same time – not sure it was related but that may be an intake leak giveaway sign. NOT TO GET CONFUSED here – the rear cylinder ALWAYS runs a tad bit hotter than the front – but should NOT BE GLOWING RED HOT – like someone put a torch to it)
Hope this helps – if it rides well don’t lose sleep over it.
(Not to go on an on – but if you ever change your pipes you will notice similar symptoms – in that the front port always has more carbon build up than the rear port)
The rear cylinder running lean is "normal" - a few of us can attest to that (including me). I have always kept an eye out for that and used to go crazy trying to figure it out – until I found the same symptoms on “all” my Vtwin bikes. In fact was reading an interesting post (see link below) and looking at the pic’s of the cylinder heads – You see what I see? There you have it – so don’t go crazy if the bike if running fine.
http://www.bigdogbiker.com/forums/dog-pound/10583-winter-projects.html
(PS. I did actually have an intake leak on one of my bikes a few years ago – if I remember correctly the rear cylinder ran EXTREMLY hot (RED GLOWING HOT) at the same time – not sure it was related but that may be an intake leak giveaway sign. NOT TO GET CONFUSED here – the rear cylinder ALWAYS runs a tad bit hotter than the front – but should NOT BE GLOWING RED HOT – like someone put a torch to it)
Hope this helps – if it rides well don’t lose sleep over it.
(Not to go on an on – but if you ever change your pipes you will notice similar symptoms – in that the front port always has more carbon build up than the rear port)
Couldnt have said it better my self.
lee
Well-Known Member
I could be talking bollocks here (probably am) but although a lean cylinder will be hot, a hot cylinder (less air cooling) doesn't make it run lean. If you have the same amount of air and fuel getting into each cylinder (hence Marv's post about a leak) then that is your A/F mixture regardless of air cooling. I can imagine the difference in air cooling between the two cylinders would have to be pretty immense to affect the colour of the plugs.
As I said - I could be talking absolute shite!
As I said - I could be talking absolute shite!
all good thoughts guys - have to admit the bike does run well - was rejetted at the shop after I bored some holes in the stock pipe baffles so I can't say if the color difference has been there from the start. The air cleaner is also stock but it does have the vented/louvered front plate which could result in directional air flow. Cheers
Zen
Zen