New headpipes bluing

[Capnkente]

Hey guys,

Just thought I would pass along a little issue that occurred to me today. I ordered a new set of headpipes from YamahaXS650.com two weeks ago and just got around to mounting them today on my recent F model acquisition. After only 10 minutes of running, they started turning colors on me. I sent Kim a message over at YamahaXS650 and they were absolutely shocked at the pics. They apologized profusely, and are sending me another set. Just thought you guys would like know.

 

[Jim]

I think I'd be concerned about that left side running too lean. You have a point and shoot thermometer?

 

[Capnkente]

I do not..........it is backfiring infrequently

 

[Capnkente]

I definitely do not want to hurt this motor. It has been sitting since 2019, but, was running good when I picked it up. Carbs will definitely need some tuning and overhaul.

 

[Capnkente]

Jim, it had a 2-1 exhaust on it when I purchased it and no bluing on the pipes at all

 

[Vincenthdfan]

Don't throw the new set of pipes on there until you do a little richening up or you'll have the new set blued exactly the same in minutes.

These inexpensive pipes are single wall, the original pipes were double wall from the factory and were more forgiving of a leaner tune.

 

[Grimly]

I'd check mixtures and balance for a start.
Not the fault of the supplier if your engine isn't running right.

 

[Capnkente]

Yeah, Dave, that's true..........

 

[bosco659]

Turning that colour in such a short period of time doesn’t seem right. When you ran it for 10 minutes was it idling or were you riding it? Only reason I ask is the pipes on my Moto Guzzi started turning a gold colour after I let it idle for quite a few minutes. Difference in discolouration from side to side would also prompt me to check air fuel mixtures.
When shooting pipes with an IR heat gun, often times I’ve seen erroneous readings because of the highly reflective surface. To combat this, I was wondering if a small circle of flat black paint on the pipes where you are taking temp readings, might yield more accurate results. After the readings have been taken, once cooled down, the paint could be removed with lacquer thinner? Silly idea?

 

[Capnkente]

Turning that colour in such a short period of time doesn’t seem right. When you ran it for 10 minutes was it idling or were you riding it? Only reason I ask is the pipes on my Moto Guzzi started turning a gold colour after I let it idle for quite a few minutes. Difference in discolouration from side to side would also prompt me to check air fuel mixtures.
When shooting pipes with an IR heat gun, often times I’ve seen erroneous readings because of the highly reflective surface. To combat this, I was wondering if a small circle of flat black paint on the pipes where you are taking temp readings, might yield more accurate results. After the readings have been taken, once cooled down, the paint could be removed with lacquer thinner? Silly idea?

I was running it at idle for less than 10 minutes......the previous 2-1 headpipes were completely shiny.......

 

[Kevin Werner]

Single wall pipes are going to discolor. Blue is lean, gold is rich.

 

[bosco659]

Single wall pipes are going to discolor. Blue is lean, gold is rich.

Oh I didn’t know gold meant rich. I thought all discolouring was related to heat, which could indicate a lean mixture.

 

[Kevin Werner]

Oh I didn’t know gold meant rich. I thought all discolouring was related to heat, which could indicate a lean mixture.

@gggGary (I think) pointed that out a while back...

 

[5twins]

I don't think gold is rich, just not as lean (hot) as blue. Usually gold comes first, then blue. Note how his blue left pipe is more gold as you get further away from the head and heat.

You put some pretty free flowing mufflers on there, did you re-jet? Or did you at least check the jetting to see if it was changed from stock? I like the '78 -'79 carb set and have sets on both of mine at the moment. For mods, you want at least 2 up on the mains, and one or two up on the pilots as well. I'm actually up 3 on the mains but I'm experimenting with XS400 needles (leaner) so I can get away with those bigger mains.

 

[Kevin Werner]

I don't think gold is rich, just not as lean (hot) as blue. Usually gold comes first, then blue. Note how his blue left pipe is more gold as you get further away from the head and heat.

You put some pretty free flowing mufflers on there, did you re-jet? Or did you at least check the jetting to see if it was changed from stock? I like the '78 -'79 carb set and have sets on both of mine at the moment. For mods, you want at least 2 up on the mains, and one or two up on the pilots as well. I'm actually up 3 on the mains but I'm experimenting with XS400 needles (leaner) so I can get away with those bigger mains.

Thanks... I am still an amatuer...

 

[Capnkente]

I'm there, bro.......just trying to survive.

 

[Max Midnight]

IMO that is pretty standard effect when using single skin pipes. Look at the old British iron and you will see that many of them will have discoloured pipes.
OE Jap pipes were double walled (i.e. a pipe within a pipe) so outer pipe didn't reach sufficiently high temperature to cause them to discolour.

 

[Capnkente]

I did notice that on my KZ1000, the discoloration begins at the head outlet underneath the collar, whereas this discoloration begins perhaps one inch away from the collar nearer at the bend. On the inside of the bend, the chrome is actually beginning to flake.

 

[Kevin Werner]

I did notice that on my KZ1000, the discoloration begins at the head outlet underneath the collar, whereas this discoloration begins perhaps one inch away from the collar nearer at the bend. On the inside of the bend, the chrome is actually beginning to flake.

Add insult to injury... I fired up the Red Bike in July and must have had oily finger prints that turned a deeper color than the surrounding gold...

 

[Capnkente]

Add insult to injury... I fired up the Red Bike in July and must have had oily finger prints that turned a deeper color than the surrounding gold...

Grrrrr!