| Author | Message | ||
     Cobrazero |
Hello everyone, I just had the exhaust crack on the front pipe just about where it starts getting larger for the bottom "bag" muffler. Now, I understand the proper thing to do would be to get an exhaust, new or from ebay, and replace it. I'm on a bit of a budget and would like to know of any ghetto fixes. The crack is like someone took a hack saw right thru the 2" pipe, but it's not that clean of a cut, and I'm sure no one actually did that as I heard it start rattling after the end of a 50 mile ride. Things I've thought of: 1) leave it as is. It doesn't sound too loud. bike appears to run ok. the gap is about 5 mm and the bag does shake as soon as you give it throttle. I have some concern of it shaking the bolts loose and falling while riding. 2) take off the whole bottom. Right now, it doesn't seem to be any louder with that 5mm gap, just wondering what performance issues might happen if I put another 2-3k miles on it before replacing exhaust. 3) weld it together. I don't have the kit for that, would need to take it to some mechanic shop. 4) put it together with some thermal wrap tape. The kind people put on their pipes anyway, except this would be on in such a way to prevent too much shaking and also seal the air gap. I'd like some ideas on how this may have happened so I can prevent it in the future. My bike has about 4500 miles on, 3k of which I've put on myself in the last 6 months. Shooting holes in my theories/other suggestions are more than welcome. Thanks for reading, have a great night! (Message edited by cobrazero on August 19, 2015) | ||
| Gearheaderiko |
Weld it. DONT cut it off and run that way, unless you put another muffler on it. Super cheap ones are available. If it cracks all the way through and you leave it-bad things will eventually happen. Tape won't do you much good, that will waste money and time. | ||
| Gearheaderiko |
Running too lean doesn't help. They bang off the ground occasionally. Lugging the engine so it shakes a lot. | ||
| Cobrazero |
Thanks for the advice! I will have a welder look at it tomorrow. Should I tighten some bolts on the front and rear exhaust mounts? Thanks again! | ||
| Gearheaderiko |
If they are loose, then tighten them. | ||
| Vsingle |
I agree, welding is probably your best option. TIG would be best; suggest stainless steel filler rods. Resist any ideas or suggestions to pretty it up after welding by grinding or filing; welds are strongest left "as is". Do you happen to do much riding in wet conditions? After suffering two different head pipe crack incidents, Both occurring during rain rides, my theory is that water quenching the hot header pipe is not a good thing. To help prevent this, I use exhaust header wrap. 12,000 miles so far on welded jardine head pipe, and no additional cracks. Yet. | ||
| Cobrazero |
As a matter of fact, I did ride in some good rain for 2 days, then the next day it had cracked. I've taken it to who I think is an experienced blacksmith that does automotive work. I'll keep your suggestions about welding in mind, Vsingle, and i'll get some wrap to put on the header. I am really hoping to ride the wheels off this blast, and in all kinds of weather (above freezing temp). Thanks again for the advice. | ||
| Vsingle |
One thing I've noticed with the header wrap is that it doesn't last very long; I'm on my third wrap in 12k miles. The first one I left bare. The second I painted per their recommendation. The third I am experimenting with some material I found on mcmaster-carr; it's expandable fiberglass sleeving. I put this over the regular header wrap. It looks really nice; I'll know in a couple of months if it does any better than plain wrap. | ||
| Gearheaderiko |
What happens to your wrap? I've had wrap on for 30,000+ miles 7+ years and it's in no need of replacement. Do you ride a lot in the rain? Without checking the box, I do think it's the McMaster-Carr brand. Black and painted black with their paint. | ||
| Gearheaderiko |
Mines just "header wrap". | ||
| Vsingle |
I have used the header wrap sold at pep boys for the first iteration, and advanced auto parts for the second and third. The first two wraps just disintegrated. Yes, I log thousands of miles in the rain each season. I also reversed NY front fender so that the long side is towards the rear. | ||
| Ezblast |
Ceramic coat - regularly. EZ | ||
| Vsingle |
What is "ceramic coat", and how many miles/weeks is "regularly" ? | ||
| Ezblast |
When it starts getting serious chips from road debris recoat with spray can touch up, but you can get it pro done for under 200. Many benefits to ceramic coating. EZ | ||
| Vsingle |
So you are suggesting omit the wrap and just use ceramic coating? | ||
| Ezblast |
Yes - reason being the wrap tends to make the metal brittle over time. EZ | ||
| Gearheaderiko |
I did both the ceramic and the wrap, Which might also be best in this situation. But there is only so many times you can re-weld the exhaust before everything is so degraded its impossible to get a reliable weld. Replacing it might be best with a good used stock exhaust, coat and wrap it (if you still want quiet) the budget friendly V&H (if noise is not an issue) or the pricier Jardine with a quiet core, if you don't mind a little noise. That's just my opinion. concur with overheating the exhaust with wrap. The excess heat containment can make the metal brittle over time. The stock exhaust does not seem like it would handle it well. } | ||
| Vsingle |
Seven years and 30,000 miles, and yet no metal brittleness? How much time does it take? | ||
| Cobrazero |
Hey everyone, just wanted to give an update. I did get it welded from and it worked great, for about 100 miles. Then it was off to rattling again, separated at the same area. I'll take it back to the welding guy, but I think i'm in for a new exhaust. I'll take a look at the options you've already mentioned, but I might just go stock for cost reasons at this time. I think i'll try welding one more time, and then header wrap. I didn't ride in the rain this week, but I do have a 55 mile commute, and it had cracked at the end of it, (last 3-4 miles) each time. I'm going about 70-75 for almost an hour most of that trip. From now on I shouldn't be going more than 30 miles each way. Maybe I'm overheating the old girl? Perhaps it's time for an oil change too, been about 3k miles and I was planning on it last weekend before the exhaust issues. Thanks again for all of your help! | ||
| Gearheaderiko |
No, you're not overheating it. Once the exhaust has a leak (or has cracked open) THAT overheats the metal. Welding used exhaust pipe is always chancy, especially where it has cracked. | ||
| Gearheaderiko |
Metal brittleness is not guaranteed, but it is a risk. It's also ceramic coated and I believe that may help matters. It's also not on a Blast which would see 5000+ rpm regularly. Which heats it up faster and stays hotter longer. But it still sees the same amount of rain and dirt. (Message edited by Gearheaderiko on August 27, 2015) | ||
| Vsingle |
If it failed at the weld, it was a bad weld. If it failed next to the weld, then perhaps the metal has fatigued; this would be unusual in steel. Do you know what type of welding was used? | ||
| Vsingle |
In my opinion, header wrap causing mild steel tubing to turn brittle is a myth. Here is why: mild steel can be heated to melting point and if allowed to cool gradually, on its own, will always retain very near the same properties as new. If this were not so, it would not be weldable material. If, however, it is subjected to rapid cooling, commonly known as a "quench", then the metal can be forced into a state known as " martensitic" which is harder and brittle. I have a difficult time imagining how wrapped headers could produce a quench event. A possibility would be cutting either fuel or spark to the motor with throttle wide open. This would subject the inside of the hot pipe to a surge of relatively cool air (in the case if no fuel) or a surge of cool air mixed with gasoline vapor (in the case of no spark). Would this be enough to provide the necessary quench (and for long enough duration?) to transform the steel to martensitic state? I doubt it. I am prepared to recant if anyone has a scientific explanation as to how mild steel might be made brittle by header wrap. | ||
| Th3wizard |
This exact same thing happened to me last month. I was somewhere between Nashville and Knoxville on the interstate when I heard it break. Found a shop that welded it for $30. | ||
| Ezblast |
Check the tightness of all your mounts. EZ | ||
| Gearheaderiko |
No scientific rebuttal! Just my experience indicates that it's a risk. But I have zero facts to back that up and your explanation seems very plausible. What I am sure about is the longer you leave a crack in an exhaust, the more likely a reweld will fail (or the more work will be needed to achieve a reliable repair). The same also holds true for an older exhaust given to rusting. | ||
| Vsingle |
In my experience, unwrapped pipes have cracked two times. Wrapped pipes cracked zero times. |
