Spark plug

[MikeL]

If no mechanical defects are discovered like a bad valve guide, broken ring scored cylinder etc. Trying out a different ignition module would be worth a try. Usually an exhaust backfire is caused by something in the ignition system. Could be a coil or the rear plug wire. Havn't seen a bad wire or a coil on a T/C yet but "Potty mouth" happens........


                                                                                                        MIKE

[starrider]

Tyner...when tinkering with the old 60s cars...i would go one heat range higher on the plug and advance the timing 5 degrees... Is it a common practice to go a heat range higher or two  on a twin cam?

Mikel...I don't think anything is broken...rings ...valve guides... when i put in a set of new plugs the engine runs great ...for a while...thinking the backfire was probably a fluke of over rich AFR at the time...probably something simple as new wires are needed...as mention by others.

The bike is still an 88 incher...don't need any more cubes...of a faster or more bigger powerful engine...and happy with the 5 speed trans. Have ridden this bike since new...a daily or rather a nightly rider hence starrider.

Thanks for your thoughts!

[Roadflyer]

If you never have to use the choke, your bike is running too rich.

[smoserx1]

 
Missed that one!

[kd]

If you never have to use the choke, your bike is running too rich.

    Took the words right out of my mouth

[starrider]

Ok...Guys this is how i cold start my RK...

(1) first to avoid kick back ( where you try to start the bike and it fails is a crashing terrible sound in the engine)...(have heard others bikes do this when rider attempt start )...ok to avoid this...with the throttle closed... i tap the starter twice with the intent to release any gas pressure build up that may cause this crashing engine failure sound...

(2) Then i twist the throttle 5 times...while NOT hitting the start button.

(3)Then i hit the starter button to start... as the engine fires up i will open the throttle  gently and steady while the engine is firing up...

(4) After the engine is running i hold the throttle open at a low rpm idle long enough so it doesn't die until engine is warm enough to take off.

(5) Now re-starting a HOT  engine is a different procedure... with HOT ENGINE i keep the throttle closed...  and with one quick tap of the starter and engine fires up immediately...if i do it anyway different it will flood and i will get a kickback failure.

Every bike has it own personality?...this has works for me...a harley tech told be about tapping the starter a couple of times to act as a pressure release (on cold start) when  told him i was having a lot of kick back starts...which cost me a new ring gear and clutch basket job. Since doing this no more kick backs...

I DO NOT RECOMMEND THIS FOR ANYONE...this is just how i have started MY bike over the past years...(disclosure)

[Hossamania]

By pumping the throttle five times, you are effectively flooding the engine, doing  your plugs no favor.
How old is your battery? A marginal battery can cause kick back, I chased that problem for a while.
Might I suggest a different starting procedure?
Charge the battery to full. Bump your starter (optional). Set the choke, make sure it stays out. No throttle, hit the starter. If it doesn't immediately fire, twist the throttle slightly, release, start again.
The key to choke starts is to not touch the throttle.
Also, do a compression test at some point if you have not already.

[starrider]

Good Morning Guys...

Ok Hoss...good to know... Thanks!...The battery is two years old...always on tender
when bike parked. When i bought the bike new... i was taught by the dealer 'not to
use choke...as they said it flooded the engine' ...so that's why i never used the choke.
In fact ...that was what the advice from them in 2000 with my first bike ...a Heritage.
'Just give the wick a couple of twists and hit the starter' was the service policy.
Like i said... i always learn from this forum...now the electrical may be a contributor...perhaps not enough juice ...battery ...coil...wires...?
....or just not running the bike long enough. Like i said...i am a everyday rather night rider. I just fire up the bike and take her for a spin for 30 minutes through town... some stretches reaching 50 mph or more. This is at night...a lot of times as late or later than midnite. So the point is perhaps the engine being ran for only 30 minutes isn't getting hot enough?...i do like to ride when the weather temp is 65-70 degrees.

Thanks!...

[SixShooter14]

Good Morning Guys...

Ok Hoss...good to know... Thanks!...The battery is two years old...always on tender
when bike parked. When i bought the bike new... i was taught by the dealer 'not to
use choke...as they said it flooded the engine' ...so that's why i never used the choke.
In fact ...that was what the advice from them in 2000 with my first bike ...a Heritage.
'Just give the wick a couple of twists and hit the starter' was the service policy.
Like i said... i always learn from this forum...now the electrical may be a contributor...perhaps not enough juice ...battery ...coil...wires...?
....or just not running the bike long enough. Like i said...i am a everyday rather night rider. I just fire up the bike and take her for a spin for 30 minutes through town... some stretches reaching 50 mph or more. This is at night...a lot of times as late or later than midnite. So the point is perhaps the engine being ran for only 30 minutes isn't getting hot enough?...i do like to ride when the weather temp is 65-70 degrees.

Thanks!...

are you giving it a bit of time to warm up?

I usually let mine idle until I can feel some heat through the rockerbox. Then I start out easy for a few bits as I get out of my apartment complex. This lets the case, cylinders, heads, and rockers get warm and expanded. Most days when it's in the 60s or more it only takes maybe 45secs or less of idling to feel the heat start creeping up from the head. Colder days take a minute or 2.

[starrider]

Good Morning SixShooter14

When i first start up... i try
to...for about 3-4 minutes...then idle off slowly as i make my way to the main drag. The reason ... don't want to piss off the neighbors...as it is late 12 midnite sometimes 130 am...and those Vance and Hines mufflers are not the
quietist ones...hence 2-3 minutes unless the weather temperature is in the 40s then
longer warm up time ...say 5 minutes... By the time i make it to the main drag...wait at a stop lite...the engine should be warmed enough.

Thanks...!      

[Hossamania]

Your bike is getting plenty warm and plenty of time to recharge the battery in a 30 minute ride. Your rides are actually pretty ideal in that regard. Keep using the tender as well.
I don't know why people are told not to use the choke. It is the proper method for starting. It will not flood the motor when used properly. I believe it is much easier on the motor than having to keep working the throttle to keep it running. It will also slide in on its own normally, though they do stick sometimes, and need to be pushed in when warm, or sometimes they don't stay out and need to be held, an adjustment nut solves that.
I have always used the choke to start my bikes for well over 25 years and 160,000 miles or more. I have never done a quick starter bump before just pulling the choke and starting. I just pull it and hit the starter. I may give a small a small throttle twist if it has been a while (a week or more) or is rather cold out. Do not use the throttle with a choke start, the throttle should stay closed.

[starrider]

OK Hoss...Thanks again! we will use the choke...