I was letting my bike warm up before heading to work tonight, and i had the choke on let it start up and run it was running for about five min i heard the idle start to pick up (the idle was about 5-6000 rpms) and i went to get on the bike and the left side exhaust (i think), right as it comes put on the head on the bend was red hot and the other side wasn't ( it was hot but not red hot) i have noticed a little bit of backfiring like a popping on deceleration (not much just in first gear). Its a 89 K/N lunchbox, Jardine RT-1 full exhaust, and pro jet kit, it just started doing it about a week or so ago (popping) this is the second time that i have rode at night this year and have just noticed the red hot pipe. before this ran very well.

I'm going to be checking the valves, any other suggestions.

Sounds super lean in that one side.  Check the plugs to confirm.

5 minutes???
That's not warm up ,  that's melt down.
1 minute for me at most when really cold. Usually 15-45 seconds. Rarely over a minute before I take off.

I think others have said that is lean. There was another past thread on red pipes.

Exhaust leak, perhaps? Check the exhaust seals. Then if that's not the problem, check the valves.

Quote from: adidasguy on April 25, 2012, 08:35:02 PM
5 minutes???
That's not warm up ,  that's melt down.
1 minute for me at most when really cold. Usually 15-45 seconds. Rarely over a minute before I take off.

I think others have said that is lean. There was another past thread on red pipes.

\

Its about 34* out. shaZam! that's what i thought, ok, so i guess i will we taking the valve cover off this weekend.

Dont rush in and take the head off before you check your ignition timing  .then the valve clearances next ,if you are confident its not a weak mixture on one side .EASY THINGS FIRST.

Quote from: twinrat on April 26, 2012, 12:39:51 AM
Dont rush in and take the head off before you check your ignition timing  .then the valve clearances next ,if you are confident its not a weak mixture on one side .EASY THINGS FIRST.

I did replace the clutch so i had the whole side off, will look at that also, as i do have a extra gasket for the clutch cover on the right side.

these are the plugs whiteish one onthe hot side, and the blacker one on the other side. replaced them with new pugs.

Quote from: knowles on April 26, 2012, 06:04:40 PM
these are the plugs whiteish one onthe hot side, and the blacker one on the other side. replaced them with new pugs.

I would've waited until you figured out what was wrong - which judging by the plugs, there's something seriously wrong. That one is black as the ace of spades.

I would re-inspect the timing pickup - aka the "signal generator" which is what I think it's called. What year bike is it?

Its a 89, i did before i put the plugs in, there was a little piece of metal on one of the posts (of the signal generator older one has two little pieces of metal that the generator spins by), i took off the little metal flake. nothing around the generator was touched or missing a piece so going to drain the oil and look at the clutch that i put in and make sure that nothing is wrong there. then it will be on to the valves. 

That's a lean condition -was the pipe glowing red? Have you ever replaced your intake boots since you've had the bike (between the carbs and head) ?
Old intake boots + having carbs on and off is when you get cracks in them-- Big air leak and not always easy to see.



As Twinrat said- Make sure it's not a lean mixture problem before  fooling with too many  things.
Post a bigger pic of the plugs .

It was 34 degrees out... warm up time varies- I've always kept them  at or just under 2500 rpms on choke initially...when it starts to warm up and starts to climb off of that while on choke - it's warm enough.

I've never seen a spark plug that was black all the way up the threads........

Could be something with the carbs as well - a clogged pilot jet or even something in your enrichening circuit (choke). That black plug looks like it wasn't even firing on that side though.

I've run across  spark plugs that were black threads from new --can't think of the brand(s)- but I doubt he has a mix of manufacturers plug wise(?).

Could be oil ( leaky valve guide perhaps )-it's an 89... Maybe not perfectly tight... threads worn in the head a little--- Hard to say over the internet.

So i put new plugs in and the left plug got black again, checked and it has spark. so going to look at the valves, the carb boots could stand to be replaced but new ones on ebay are $126. (will check with starter fluid to see if there is a leak). now that i have a portable gas can, i can run the bike without the gas tank and work on it, makes it a lot easier to work on the carbs. will report back, check the oil not low nor has it been since oil change (about 800 miles ago)

Intake boots are 30-40$ each at the dealer.  They are  about $26 each  on bike bandit. That $130 ebay auction- guy is on crack.

Don't buy used ones.

EDIT:

Keep an eye on your oil level- see if you're using oil... Does the black wipe off easily?

not using oil, as i have been checking after most rides or when i put gas in it. yes it does. off new plugs at least.

well ordered the valve tool, at least if thats not the whole problem it will help, i would shaZam! a brick if they are all fine. other than that will look at, carbs, and carb boots to see if there are any leaks. now to sit and wait.

Quote from: Jared on April 27, 2012, 08:06:32 PM
Intake boots are 30-40$ each at the dealer.  They are  about $26 each  on bike bandit. That $130 ebay auction- guy is on crack.

Don't buy used ones.

EDIT:

Keep an eye on your oil level- see if you're using oil... Does the black wipe off easily?

Bike Bandit is on crack too. 

People please!

www.ronayers.com  Click on the "Fiche" button up at the top.

$12 for intake boots.

I think I just recently posted this in another thread, but it bears repeating everywhere.  Ronayers has had the cheapest price for like 99% of the OEM parts I've ever searched for.  Often by a considerable sum.  (Over 50% in the case of these intake boots)  I think that the only place I'd come across that ever beat their prices is now out of business, and it was never by more than a few cents at most anyways. 

If you're going to order online, it makes little sense to order anywhere other than Ronayers. 


I'm not affiliated with them in any way.  Just a more than satisfied customer. 

Quote from: dougdoberman on April 27, 2012, 09:22:16 PM


Bike Bandit is on crack too. 

People please!

www.ronayers.com  Click on the "Fiche" button up at the top.

$12 for intake boots.

Good to know.

Holy balls less then half of every place i can find, shipping was a little bit expensive but they did save me over $30, so not bad, thanks for the info. Where has this place been? They need to fire their web designer, but i will be back to the site.