Exhaust Header Temperature Question

[z1eyedjack]

What is indicated by one exaust header being A LOT less hot than the other two.  #1 and #5 were hot to the touch after a 3 min warm up while I could more easily touch #3. 

Is it possible that 1 and 5 are running too lean? I felt that they got way to hot too fast.  And shouldn't they all be relatively the same temparature as each other and all reach that temp at roughly the same time?

[R J]

From the surface, it sounds like #3 is misfiring.......

[98valk]

What is indicated by one exaust header being A LOT less hot than the other two.  #1 and #5 were hot to the touch after a 3 min warm up while I could more easily touch #3.  

Is it possible that 1 and 5 are running too lean? I felt that they got way to hot too fast.  And shouldn't they all be relatively the same temparature as each other and all reach that temp at roughly the same time?

had the same problem. first replace the intake manifold o-rings.
if not that, then it is the vaccum diaphragm of the oem petcock is leaking preventing full fuel flow all of the time. 
also mine were more pronounced for the forward cylinders since the forward carbs receive their fuel from the middle carbs, whereas the middle and rear carbs received fuel flow directly from the tank.

[Ricky-D]

What is indicated by one exaust header being A LOT less hot than the other two.  #1 and #5 were hot to the touch after a 3 min warm up while I could more easily touch #3. 

Is it possible that 1 and 5 are running too lean? I felt that they got way to hot too fast.  And shouldn't they all be relatively the same temparature as each other and all reach that temp at roughly the same time?

The first thing to do is perform a compression test.

You cannot accurately diagnose a problem such as you experience without knowing that the motor is in tip top condition.

Absolutely!

***

[z1eyedjack]

What is indicated by one exaust header being A LOT less hot than the other two.  #1 and #5 were hot to the touch after a 3 min warm up while I could more easily touch #3. 

Is it possible that 1 and 5 are running too lean? I felt that they got way to hot too fast.  And shouldn't they all be relatively the same temparature as each other and all reach that temp at roughly the same time?

The first thing to do is perform a compression test.

You cannot accurately diagnose a problem such as you experience without knowing that the motor is in tip top condition.

Absolutely!

***

Did a compression test already.  All cyl are at 155 psi.

[Thunderbolt]

has a restricted or colgged slow jet.  First try some Seafoam or Techron in the tank something like half can to a tank of fuel.  It might smoke a little till it burns off.  If that doesn't help after a couple of tanks, you will need to clean that jet by some manual method.  The orifice is only .035" and it doesn't take much to clog it. 

[9Ball]

has a restricted or colgged slow jet.  First try some Seafoam or Techron in the tank something like half can to a tank of fuel.  It might smoke a little till it burns off.  If that doesn't help after a couple of tanks, you will need to clean that jet by some manual method.  The orifice is only .035" and it doesn't take much to clog it.  

0.35 mm or 350 micron, not 0.035 inches

.035 inches would be 0.89 mm

[Thunderbolt]

pretty small orifice anyway.

[John U.]

+1 on the clogged slow jet diagnosis. I find Techron to be more aggressive. Don't expect instant relief though, Run the bike, let it sit overnight, run it again, let it sit again, etc.
If no joy it's time to get busy. You may find as I did that replacing the jets is preferable to trying to clean them.

[z1eyedjack]

Thanks for the reply guys.  I was actually thinking that #'s 1 and 5 were the issue since they just seemed way too hot to quick and that 3 was ok.  So, if it is 3 that has the issue then, does that mean that synching the carbs correctly would be near impossible if the jets were clogged and needed cleaning or replacing?  After all, all the other carbs are being synched to #3. 

Or is it that this is a case of 2 cyl are out of line rather than just the one?  Should the pipes coming from the header get that hot so fast?  I had it on choke for literally 3 mins before I checked the temp and I almost blistered my hand on 1 & 5.  I just felt like maybe I've got too lean a mixture in 1 and 5 and more correct on 3.  Maybe I should check Morgan's Colortune to see what result that give me before making any conclusions?  Anybody have any experience or success with that tool?

[Robert]

Its a exhaust and of course its supposed to get that hot that fast especially on choke and if you have the smog stuff on then it will get that much hotter faster. Air is pumped into the exhaust to complete combustion. If its to lean the bike wont run well, lack of power, Why would you want to sync your carbs if you have clogged jets? Plus running on choke is not a diagnosis for clogged jets nor anything for that matter. How does she run warmed up? If you want see where they are at as far as sync this could also cause one pipe to be to cool. The choke also not being applied evenly can be a problem its not a precision piece. You cannot tell anything much with the choke on, and with it off unless you have a heat gun you wont be able to accurately tell anything especially unless you take her out for a small spin. I can tell you this unless its below 45 degrees you shouldn't have to have the choke on. If this is not happening for you then it more than likely is to lean. I also wouldn't let the bike run with the choke on longer than necessary nor let it warm up with the choke on. Has a nasty habit of washing the oil off the cylinder walls and bluing the exhaust.I think we have covered all the points thank you for your cooperation

[z1eyedjack]

Why would you want to sync your carbs if you have clogged jets?

It's not that I wanted to sync  my carbs with the clogged jets.  It was only recently that I started thinking it was clogged jets after several posts suggested such.

How does she run warmed up?

She's got power, but as I mentioned in a previous post of mine, she's not idling steady and there's a strange feel sound when she's under 3k rpm.  Like a fluttering, popping and slight hesitation.  But if I get on the trottle, she takes off.

I can tell you this unless its below 45 degrees you shouldn't have to have the choke on. If this is not happening for you then it more than likely is to lean.

This is interesting.  Because the previous owner I purchased it from told to me to always let it warm up with the choke fully on for 3-5 mins and then for another min or so half way.  And he lived in FL too.

Thanks.

[Robert]

As for the jets and the fluttering even the warm up let me suggest that you may want to go over the carbs. Its not a firm diagnosis but it fits all the things you are bringing up. Plus if you are going to get into the carbs the easiest way to do that is a jet kit maybe even if one was already installed. I too am in Florida and could have used my choke once last year but opted to let it crank just a bit and then start. These bike are set up lean and that's a problem because you want a lean cruise and the rest at a richer mix. This gives you good starting idling and top end and the cruise will get you good mpg. The way they are set up now its just lean. The choke because it lets extra fuel into the engine is not good but sometimes necessary. It can wash the cylinder walls and cause a blue exhaust and takes extra fuel. If you start and can comfortably drive off this is the best. It brings the engine up to speed faster and you can take the choke off sooner or not use it at all. putting on the choke can also cause one cylinder dropping out due to flooding, (cooler exhaust in one cylinder).Let me also just say its kinda like oil yes in theory it does make a difference but in the real world you will more than likely never have problems with the cylinder wall. So if you want to warm up then OK its just not the best way and more than that says that the mix is more like the factory, to lean. These bikes when setup properly will have no problem starting cold down to say 45 degrees and even driving off cold without a choke on. I'm a little anal when it comes to setting up a engine to run at its top performance in its present form aka minus major mods. So when I hear some one maybe not with the best mechanical skills thinking how to bypass something that may be a problem it kinda drives me buggy Even though this was not the intent but a miss diagnosis. I would try Techron and see if that makes a difference and if not and you mechanical skills are up to it then tackle the carbs your bike will thank you and of course the grin factor will be there.