Hi All

Was out for a ride last night and a mate noticed my rear pipe glowing when giving it the beans, by the time we came to a stop it had stopped but he kept an eye on it for the rest of night and it happened a couple more times, only really when travelling at above 70mph or accelerating hard.

Bike is running the stock carb with a 190 main and a 45 pilot (if i remember correctly) RSD open filter a Hi-4 ignition that is advanced a bit i think up to number 7 of 10, screamin eagle coil and leads and a pair of supertrapps

The Y piece it was glowing from has been repaired after splitting and i have a brand new Y piece sitting in a box (ebay bargain) that i was going to put on over the winter

I read somewhere the pipes would glow if it was running to lean is that correct? again if i remember correctly the mixture is about 2.5 turns out.

What do i do? will it cause damage? i am off in a couple of weeks on a 600+ mile weekend so would like it to be sorted before i go.

Cheers
Neil

 

I've seen pics of engines on test beds with the entire system glowing bright and pretty impressive it looks too! That Y pipe is also a bit of a nightmare as exhausts go, so I'm not surprised if it is a hot-spot. Does your mate have a Harley and does his do this too? You could be pushing forward the frontiers of exhaust study here!

 

Yes he does (cross bones) and no his doesnt!

i didnt actually see it myself, couldnt catch a look while riding at that pace! im just a little concerned i could be doing damage somewhere

 

You're just thrashing the life out of it! Joking aside if you consider the colours that pipe turns to, blues and browns etc when cold, ir is getting pretty hot at some times. My first Harley, a shovel, was my first experience of bikes with shiny heat shields and I was horror struck at the state of the pipes the first time I removed the shields. Nothing surprises me now!

A rudimentary google suggests exhaust temperatures are around 700 degrees C coming out of the head, which corresponds to red hot. So it doesn't sound as if your pipe is unduly hot, although this is hardly a scientific analysis!

 

I wasnt hanging around when it was glowing i hadnt dropped below 80 for about 10 mins or so. Since fitting the batwing its just so much nicer to ride it at higher speeds

 

Could be normal for your set-up, or you could have an air leak at the gasket, possibly a pin hole on the weld/repair on the Y-pipe causing an "afterburn" of the exhaust. Hope this helps. Remember don't ride faster than your guardian angel can fly!!!!

 

Ok thanks for the input, i may see if i can get the time to fit the new Y piece in the next couple of weeks to rule that out.

 

Be sure to check for an intake tract leak also while you're looking it over. A leak can/will cause a lean condition that will make things real hot. Good Luck.

 

"giving it the beans" I like that especially with some fried taters, a green onion, cornbread, and sweet tea. (It's getting close to lunch)

Anyway, have you looked at the plugs? They should tell you if you're running lean or not.

 

Mine does the same. I have short pipes and even get dual blue flames about 4 inches long. I have toqure cones and plugs are a dark brown.