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That's right...there are many others like it, but this one is mine!

Pretty standard, similar to what many others have done. Got a big 'ol PVC elbow from Lowe's for a couple of bucks. Scavenged bolts and misc. hardware. Cut off one end to match the fan O.D., sanded it flat and JB welded at the joint (ground relatively smooth after curing). Clamps also securing. Cleaned and painted all flat black. Noticed that the pipe was a little too close for comfort to the exhaust, so I fabbed a ghetto heat shield for the bottom of the pipe from a strip of aluminum and some graphite gasket material.

This big boy was protruding just a little too much, so I had to cut out a well in the fender. Dremeled this with little issue, had to put in a second cut to accommodate flex of the back end. Sealed the rim with some hi-grade automotive stripping. Expensive as hell, but I can't say how wonderful this stuff is!

Pipe was $4. Stripping was $10, but I've now got lots of this stuff left for future projects. Satisfaction of making it myself, from entirely "off label use" materials: priceless. ;D

Ugh...this is one of my biggest pet peeves...

I live in a fairly hilly area (especially backroads - prime scootin' territory of course), and it seems that practically EVERYONE wants to live on top of a hill with a big, long, gravel driveway that runs right into the road. Predictably, it rains, and all the gravel just runs out into the road. Do any of these driveway owners give a rats arse? NO. They just leave it out in the road until traffic knocks the worst of it out of the way, making it relatively scoot-safe again. I actually have memorized all of these on my "daily" routes, and make a conscious effort to be more careful around them after it rains.

Yes, it's absolute murder on a bike, but it's even dangerous to cars. I personally feel that people should be held legally responsible for this sort of thing. I mean, if I poured an oil slick in the middle of the interstate and killed 20 people in the ensuing pileup I'm pretty sure somebody would be after a piece of my hide, right? I don't see this as being any different. It's boobytrapping the highway by way of negligence by the property owner.

I'll just end my rant there. Glad your pops came through relatively unscathed, damin.

My apologies for the long wait to whomever might still be inexplicably paying attention...

In short: Ghetto gasket = FAIL.

I cut two nice diamonds out of the aluminum flashing, and bound them together with about 3mm of ultra copper for a primo-looking ultra copper sammich. This was a pretty badass ghetto gasket, IMHO. Bolted it up and was good for about 70 miles, then I heard it get louder and louder as I was riding...got it home and looked under the scoot to find ultra copper was forcefully blown right out the side and all over the shroud like a sneeze on a buffet - seriously, this stuff went straight to hell. I had expected a little more from the ultra copper, really.

Unbolted to try to find the failure mode, to find that only *half* of the gasket was still there! By that, I don't mean that the plates were left, no no...the aluminum and all burned clear in half, on both plates! Gotta say, I was impressed. Half of the entire gasket was completely GONE. Road litter somewhere, I would imagine.

Failure mode was apparently that the ultra copper just burned out, so no use investigating further.

This left me scootless for a while. Ordered 2 different types of ring gaskets, hoping that I would have better luck. Ordered from a vendor on Sunday night, paid for priority shipping. Monday was a holiday, that was all fine and dandy, but the damn things didn't ship out until THURSDAY NIGHT. Fat lot of good priority shipping does when it takes 3 days for a vendor to put 2 rings in an envelope. Bad form, unnamed vendor! USPS then proceeds to hose me by claiming they "attempted delivery" on Saturday. Pfft...

Finally got my parts the following Monday, one copper donut and one 'OEM' (aluminum?) donut with some mystery thermal goo around it. Chose to go with the OEM 'mystery goo' first, as it was slightly thicker and seemed to fill the recess a little more snugly.

Cleaned everything up, started bolting back together, and was giving the nuts one final twist when *pop* - out comes my thermosteeled stud. Needless to say, I was not happy at this point. All my ghetto engineering had failed. Not a high point in my personal scooter chronicle. Thermosteel looked like it had done it's job, there just wasn't enough thread left for it to grip to.

So, I procured a 1/4" tap from the parts house and proceeded to clean and re-tap. This was slightly tricky, as I had to tap from underneath with the pipe still attached - I'd already started crushing with the other stud and didn't want to waste the gasket. Unfortunately, the tap seemed way too easy - not sure if tap size was a little off, or if the hole was just a little too wallowed out. At any rate, I decided to use a high quality stainless steel 1/4" Allen head cap screw instead of a stud. This twisted in with little fuss, and is now extremely secure - I really think it may have finished tapping it's own thread. Tripple nutted both studs, crossed my fingers, and hoped for the best...

So far, so good! Bolts appear to be holding, and gasket appears to be...well, 'gasket-ing'. 4 or 5 good rides in now and nothing appears to have either loosened up or sprung a leak, so I'm tempted to call this repair complete.

One thing I noticed was that the casting in the flange area on the head was piss-poor. Convex areas from the fin ribbing ran clean across the flange face. You'd think they would have at least went to the trouble to grind the face flush, but nooOOOooo...pretty much any flange gasket would have been doomed to failure from this alone. Guess that's why Lifan went with the ring instead, eh?

In conclusion, EG's thinking points from this adventure:

1. If it's stripped, it's just stripped. Re-tap it by whatever means.

2. Never assume a mating surface is actually flat, even if all engineering logic dictates it will be. A good reminder that this IS Chino-fab we're dealing with, after all.

3. Thermosteel is good stuff. It can't hold pressure in absence of good thread though. See point #1.

4. Ultra copper also good stuff. Screamin' hot scooter exhaust gas is just a bit much for it - it can and will re-liquify under heat and pressure. Seems to make great ghetto loctite, though!

Thanks for all who have read and/or contributed to this thread. Mods, you might want to move this to the exhaust section so it might help someone out later down the line...

**walks back in from garage**

Well, it's done...here's hoping it works! They didn't have the ceramic compound I was looking for at the parts house, so I wound up with some of this goop:



Thermosteel..."cold weld" compound, used for patching up cracks/holes in blocks, heads, manifolds, and the like. According to the package, this stuff's good up to 2400f! That's hot! The mere 1200f coming out of the exhaust port should just cure it up nicely then. Says it gets stronger with heat too...we'll see about that!

I cleaned out the hole with carb cleaner and Q-tips, then mixed up the magic goo. Consistency is kinda like JB weld, with pulverized metal shavings in it. It was thin enough when mixed to get drawn up into a syringe, which I used to blow the stuff up in there. A lot of it ran out, but I was able to get a good bit up in there. Surprisingly, I found the stud that had fallen out on the garage floor, so I cleaned it up and used it instead of the one I made from the SS (hell, I gave $2.50 for this thing, I'm gonna use it!). Dipped it in some of the pastier stuff left and screwed it in using triple nuts on the external side to try and keep those threads clean as the excess goop squeezed out when threading it in. I could definitely feel the metallic bits 'crunching' as I was threading, which I took as a good sign. Pulled off the triple nuts and cleaned everything up with more Q-tips. Now to let it cure overnight...

When I pulled off the pipe, I was quite dismayed to find that the new gasket had fried itself to death on one side. Boo! I think I'll be making my own gasket this time, if I can find some material that will take the temps...we'll just have to see what wonders the parts house holds in the morning. Failing that, I might try to refurb the old one with some of the ultra copper, depends on how desperate I get.

On the bright side, the gasket I made between the muffler and the pipe is holding up nicely.

Picked up my poor workbenches a bit, they'd taken a beating over the last couple of months. Used the down time to throw a couple of body clips on that had been missing for a while too.

So...to the parts house in the morning for gasket material. Cut new gasket, bolt the pipe back up, and let her warm up at idle for a while to set the paste. Let it cool down...check the bolts...then if all's well I fire it back up and go for a ride! ;D

Well, AS got my gasket in Friday afternoon - sweet! So much fuss over such a simple little thing...

My trip to Ace got me a new heat-treated 6x30mm stud, a roll of some hi-temp gasket material, and some loctite 'red'. One-stop shopping, indeed.

Used the old pipe/muffler gasket to make a pattern on the new gasket sheet, and bolted the exhaust back together. New gasket material isn't as thick, but hopefully will do OK.

Against my better judgment, I decided to listen to everyone's advice and forego any type of sealer inside the stud hole in favor of anti-seize. I figured this is going to be a progressive repair, stepping up in degrees of severity until something 'sticks', so that was the place to start.

New stud went in, manifold went on, held in place by a heat treated lock washer and double nutted with standard steel nuts. Nice.

Fired it up and all seemed well. After a week of 'not scooting', I was tickled to be back on the road for a test ride! Things seemed to go well...sound was 'normal' on accel...deccel was not 'poppy', just a nice "grrr" sound, which I took as indication that the gasket was doing its job and exhaust gases flowing properly. Rode about 10 miles this way and brought it home to cool off while I went out for some Chinese food (no, the irony is not lost!).

Waddled home from the buffet and decided to have a look-see to find out if any of the nuts needed tightening up after the ride. Got about another 1/4 turn on the muffler clamp bolts, as expected. Looked at the flange and found that, to my horror, the new stud was gone. Yep, that's right, just fell right the eff outta there. About every swear word I know escaped my lips at this point, and I believe I may have actually created some strange new ones (urban dictionary said they'd get back to me on that).

So...not enough thread there to hold it in place, vibrated loose, and fell out. Boo on this, both because it left me back at 'point A', and because I gave a whopping $2.50 for the stud that's now road debris somewhere.

I had thought the thread O.D. and depth on the new stud looked a bit thin to begin with - yeah, it's M6 blahdeblah, but it just seemed a bit fine to me. Thought perhaps the failure might have been due to a combination of thread size variation and the lock washer putting undue extra pressure on the threads, so I replaced with a stainless 30mm allen machine screw with flat washer and double nuts as spacers. All looked well, so I fired 'er up and went for another test ride.

Behavior was again fine on the ride, good sound and no problems. Unfortunately, when I got back to the garage and had a look-see, the bolt was gone just like the stud. Barring the possibility of exhaust-stud-munching gremlins, it would appear that there just isn't enough bite left in there to secure a standard M6 anymore. The anti-seize might be working a bit *too* well also.

So...I have a gasket now, that is functioning and holding in place courtesy of the remaining stud, and a half-stripped hole full of anti-seize. First step's getting that anti-seize goop outta there. Next step is up in the air...

I can thread M6 into the hole and have it hold just until heat and vibration enter the picture, at which point it lets loose and vibrates out. I'm still tempted to use some kind of goop to try and fill the gap between and solidify the seat. Bad thing is, there would seem to be very little in the way of goop that can stand up to this kind of heat.

Speaking of which, anybody know for sure how much heat we're dealing with here? I've read up to 1200f, but I don't know how accurate that random internet factoid may be. Most goops, even hi-temp goop, will only hold to about 500f. This includes JB weld and Loctite products.

Leading candidate seems to be this Permatex metal compound, or putty, both of which claim to not only withstand up to 2000f, but to actually set better with the heat:
www.caswellplating.com/permatex/permrepairprods.html

Seems to be a ceramic, which is interesting. Explains setting with the heat, at least.

So, I suppose I'll saunter on back to the parts house and see what they've got that's comparable. If it doesn't hold, well, I'm no worse off than I am now. Either I try this and it works, saving me from having to drill/tap, helicoil, or replace the head, or I have to do one of those, which is exactly what I'm looking at now. If I go the retap route, I'll likely try and go for a 1/4". Mixing metric and standard is never good, but a stripped M6 is about perfect for a 1/4", and the 1/4" stud will likely fit the opening in the flange to boot, saving me the trouble of having to drill that out too (which is really no big deal anyway, but easier is easier any way you slice it).

Not that anybody cares about me and my half-stripped thread, but if I can find an easy fix for what's apparently a fairly common problem, it might help someone further down the line, so well enough to post here for posterity's sake. Helps my own thought process to document it too. If nothing else, I'm making a nice "won't work" checklist! ;D

Well, it would seem that I've avoided any significant damage, but that all remains to be seen I suppose. I'm hoping that I at least had the flange polished and secured well enough that the leak wasn't terribly bad. I was getting only just a little bit of 'putter' when letting off the throttle, which was what tipped me off to look in the first place. Only physical signs I see is a little chalkiness on the flange on that side (already re-stove blacked ;D) and a little melting of the plastic on that side of the shroud (which was there when I bought it).

Will probably go to Ace and/or the local auto parts houses tomorrow to see if I can find some new exhaust studs. I have the old one, but threads were slightly damaged and I just don't trust it based on a) suspecting it's cheap steel and b) in a state of highly dubious structural integrity due to the aforementioned cheapness combined with 2.5km's worth of heat cycles. Not exactly a promising combination for long-term integrity.

Failing that, I did get some high quality stainless 6mmx30 machine screws I can cut the heads off of to use in a pinch. I've heard both ways about using SS in aluminum, but I'm thinking for my purpose having it weld itself in place might be just the thing...

In the head itself, I've got approximately 15mm of thread, with 5 missing/damaged smack dab in the middle. My goal for repair is to do the best I can to hold it together without pulling the head. If I pull the head, I'm just going to put a new one on, and that would be a huge PITA for me, so repair in place is the hands-down preferred option. I want to just get another stud in place, lock it down, and *hopefully* have it remain there for the remainder of the life of the engine. This made SS an attractive option, and probably either red or possibly even green loctite up in there. (No offense, mthomas, I'd normally agree with you but this situation calls for it, IMHO.) Theoretically, that'll hold the stud securely in place. Then use either brass/copper, or failing that, heat treated steel hardware to secure. I'm thinking double-nutted with a lock washer for maximum adhesion and thread protection.

Absolutely Scooters got my package shipped PDQ yesterday, and confirmed that it will fit the 1P57QMJ. If the USPS cooperates, I will hopefully be back on the road for the weekend.

Took the opportunity to have a closer look at the exhaust while it was off...my, my, my...bad form! Lots of ugly 'weld boogers' disrupting my airflow both coming out of the pipe and going into the muffler. A few minutes with a rotary tool and a carbide burr took care of all that silliness. Damn 'pig iron' pipe had already started rusting back in spots, so it got another generous helpin' of stove black, as did the muffler where it had gotten scratched when dismounting. All is shiny and well again there. ;D

There was indeed a gasket present between the pipe and muffler, thankfully. A bit questionable how well it was sealing due to waviness on the muffler face, so I hit it with the 'ol mouse sander to try and smooth it out, as well as rough up the surface a bit for a better seal. Going to run a bead of gasket maker around the outside before reassembly just to help make sure everything goes back together and seals well. Polished the flange with some fine grit too, for the same reasons.

So, there's today's update. I'm cautiously optimistic as to repairability, and looking forward to being back on the road. This weather taunts me so...