Hi all-just joined this site and this is my first post.

So I have a 2004 HD Road King Classic EFI. At the end of last season I was have an intermittent problem with high idle and occasional stalling. After research I replaced the engine temp sensor (I figured it was reading a cold engine even though it was hot, and then was dumping more fuel causing high idle and would flood at times). Anyhow, I have ran my bike a few times in the garage (can't ride because Michigan winter) and I've let it get good an hot to see if I would get the high idle or a check engine light like I used to. So far everything seems good. Well, yesterday I go to run it and the bike ran at a high idle from the start for longer than normal (I'm talking about the regular high idle that is normal for a cold start on and EFI motor). When it did settle down I noticed that the exhaust was glowing red right where it comes out of the rear cylinder. I've never noticed this before, so I'm not sure if it's 'normal' or not. Although it was real cold out (probably about 10 degree F at most) I should also mention that the bike was only running, so there was not air moving past the cylinders keeping it cool. So what do you think-is this an issue?

 

I to am new to this . I would check intake gaskets sounds like it could be running to lean,pos from vacuum leak . to much fuel or rich condition will turn spark plugs black and foul them . white plugs are lean black plugs are rich they should be kind of a grayish or tan color. check this first good luck

 

A vacum leak will increase the idle. Squirt a liquid(NOT GAS) around your manifold gaskets. If you are having cabin fever and running your bike at idle for long periods then the purchase of a large shop fan from Lowe's or Home Depot would be a wise investment. Take Care Fairshake

 

if your exhaust is glowing you have a serious problem...do not ride the bike!..You likely have an intake manifold leak. idle the bike and spray wd40 on the intake flanges.......If any change in the idle speed is noticed you have a leak...fix it.......really hot things destroy air cooled motors

 

Make sure you are vented well in your shop when running your bike. can kill you.

 

I installed yaffe skirt blowers on my bike over the winter. I had the same issue when I started it for the first time, the rear cylinder pipe seemed to get too hot. When I checked the plug everything looked fine, not running lean. I never had high idle issues but I was thinking it shouldnt be cherry red.

I was thinking that because it was a new pipe and very cold out it could have been dumping a ton of fuel and heating it up. Plus the inside of the pipe did not have any carbon build up and the heat transfer could be very high.

My rear cylinder was very different than the front cylinder, so I started retuning the bike to cool the rear cylinder down. As it has gotten warmer it seems to be better. I am wondering if the way the bike is tuned that with low temperatures (below 25F) the bike runs very rich and causes that condition.

I can tell you you probably had the same - oh crap, thats new - feeling in your gut that I had. I never noticed the rear cylinder doing that before with my vance and hines, but then again I never really looked for it. I was always curious as to what others witnessed in colder weather with their fuel injected bikes.

 

I am not sure why exhaust pipes might not glow "cherry red" up in Canada, but down south they glow all the time, but it is not normally noticed. I was once cruising along the interstate late at night doing about 75 mph. A group of about a dozen Harley riders came up from behind and were passing me. As I looked over at them I could see the "cherry red" signature of their exhausts glowing in the dark (right up by the exhaust port). It was actually the first time I had ever witnessed that phenomenon. It would be very difficult to see it looking down on your own engine, but it happens all the time.