Hot Cylinder

[2qmedic]

Helping out a friend.
1999 I/S <30k miles
He says that it is "Not running as smooth as previous" (of which is still pretty good).

I have found;
Right bank of spark plugs look good, Left bank have a little carbon build up...Hmmmmm
2nd right cylinder exhaust (Cobra pipes) noticeably discolored due to heat.
Air filter replaced less that 3K miles ago, no other maintenance has been done.

I'm thinking:
1- A good seafoam treatment 1st to rule out decreased fuel to that cyclinder.
2- R&R vacumn lines
3- Carb sync with a new set of spark plugs

Any other thoughts???

Thanks in advance

[Pete]

If it is missing on one cylinder, you need to identify WHICH cylinder before going further.

It may or may not be the blued pipe cylinder.

It is always possible that there are 2 problems, miss and blue pipe.

[2qmedic]

1-Middle cylinder on the right bank (didn't look up the cyl#).

2-Spark plug is not missing, this spark plug was the whitest of the 6 possibly indicating a lean condition.

3- The blueing on this cylinder header is abnormal. The blueing on the other cyclinders and even my cobra exhaust are no where near this one in question.

4- Not known if it has the cobra kit or not. However, it has better throttle response than my I/S with cobra pipes. His will lift the front wheel.

[Ricky-D]

Maybe just a change from where he regularly get gasoline might help with the running issue.

One pipe turning more blue that the others could be for a number of reasons.

A temperature check will help to eliminate the reason being the pipe itself.

I think there is most likely no serious problem and eventually all the pipes will eventually turn the same blue.

***

[2qmedic]

I'm not worried about the "not running as smooth", it runs well.

The indicators at this point "white plug and excessive bluing on same cylinder" - points to a lean mixture.

He has had these pipes since before I knew him (2 + years).

[Ricky-D]

Worrying about the plugs,  white is not "total destruction" and it would indicate a colder plug should be the way to go.

The pipes are a contributing to the lean running condition and it's been stated on this forum many times that the Valkyries are a lean running motor to begin with.

Most will suggest going to the next size up "idle jet" which would be a #38.

Some will say to shim the needles.

Larger main jets would be the very last thing to do.

Premium gas will have some affect, although very little.

As a note here, too rich a condition will also blue the pipes.

Spark timing will also have an effect!

Merry Christmas

***

[Chrisj CMA]

my guess its the intake runner screws (clamps loose) will act like a vacuum leak and cause lean conditions.  Check all 18 screws.  Changing vaccum lines is good but dont forget the little plugs on the unused tits.....they can "look" fine but be dry rotted

[2qmedic]

I was also thinking about a vacumn leak there also.

Seafoam is in the tank, will run it again Sunday after church and replace the vac lines.

The plug for that cylinder is too white for a normal condition, that exhaust is BLUE down and extends back horizonally 4 inches past the vert/horizontal bend. All others and my exhaust just extends 2-3 inches out of the head.

thanks for the input

[Valkpilot]

I was also thinking about a vacumn leak there also.

Seafoam is in the tank, will run it again Sunday after church and replace the vac lines.

The plug for that cylinder is too white for a normal condition, that exhaust is BLUE down and extends back horizonally 4 inches past the vert/horizontal bend. All others and my exhaust just extends 2-3 inches out of the head.

thanks for the input

As suggested, I'd check for vacuum leaks, but I'd also check for a failing petcock.  Inconsistent and uneven fuel distribution is one of the hallmarks of a leaking diaphragm.

[Pete]

Vacuum leak? Possible
Clogged Pilot Jet? Possible
Pilot jet needle, out of adjustment? Possible
Throttle out of sync? Possible

All can result in a lean condition. Check the the easiest first and eliminate each one and you should find the problem.

[2qmedic]

I'll be puling the tank next and repl vac lines,
will check linkage also - good point

[waynedee]

Man my first time here...Great advise guys..I have a 99 Valkyrie Interstate with 17,000 miles on it and I have the same situation with my cobra pipes turning blue...Im changing out my vacuum lines now and Im gonna try some seafoam...

[2qmedic]

Update on the Valk:
The Valk got a good seafoam treatment,
I cleaned the sparkplugs & reset the gap,
Replaced the vac hoses,
Tightened the intake runner clamps (all 18 of em),
Checked choke linkage to ensure that the choke was indeed returning to a complete off setting.

He picked up the Valk the other evening and I received a report that it was a definite improvement, has even better throttle response and just plains runs great.

We'll check the plugs again, clean the headers and then monitor to see if that cylinder returns excessive blue again.

Thanks for your thoughts folks,

[Ricky-D]

I think the "placebo effect" comes into play a lot of the time.

"Happy New Year"

***

[2qmedic]

You know... I think the Howard Cosell syndrome "A Legon in his own mind" keeps showing up in the threads.

[Smokinjoe-VRCCDS#0005]

I think the "placebo effect" comes into play a lot of the time.

"Happy New Year"

***

Sorry if I took any of your thunder ol' great tech one with the dictionary so you can dazzle .Just showing a new member " waynedee " nothing he can do will stop the Cobra's from turning blue and a few option's to cover them.Picture's removed  

[2qmedic]

But But But... they were some great Valkyrie pictures!!!

[Smokinjoe-VRCCDS#0005]

But But But... they were some great Valkyrie pictures!!!

I agree      I do hope you get the problem figured out.My Interstate only got about 300 miles put on it over 4 years from the guy I bought it from. It had a dead spot when stretching it out. I used several cans of Seafoam and couple bottles of Tecron it was'nt until I used Lucas that it straighten up....Runs like a new one now .

[Madmike]

There has been lots of advice given that will hopefully help you resolve  your problem.  I just want to add that a hand held "temperature gun" is a handy tool to have for helping to identify problems and there are lots available now that mean that you don't have to break the bank anymore to get one.  Here is a URL to one as an example  - I have no idea how good it is or anything else just wanted to show a picture to those that may not be familiar with them.


typical non contact infra red thermometer

[2qmedic]

Wel, he picked up his Valk and I received the report that it runs like it shoud now. 
I didn't get a chance to ride it again before he picked it up to realize any difference.
We'll probe a little more to see if that one cylinder is running too lean.
We talked aout running the Techron in it also, he is going to put some of it through the tank for good measure.