unclogging the exhaust....

I recently aquired a 1980 Puch Maxi that was left for dead, and thanks to Fred's Guide on this site she's now running great. Or almost great. I think the remaining problem is that the exhaust is pretty clogged up, I get hardly any air at the end of it and it runs stronger without it.

So I'm about to try the recommended method from Fred. He says to put it in a campfire with a wire inside it and let things get really hot and then poke it with the wire. Does anyone have anything to add? Any advice? I'm about to try it and am trying to get as much info as possible.

And if anyone's curious, the reason this moped was left for dead is the points were completely fouled (I scrapped a lot of black soot off them), the carb was a mess, and the petcock wasn't letting any fuel at all thru.

Re: unclogging the exhaust....

Just go with Fred's advice and paint it up later. The main thing is to get rid of the carbon. Maybe later you'll want to check with Mopedwarehouse for a performance exhaust?

Re: unclogging the exhaust....

Funny, I already have my eye on that performance exhaust. $78, can't go wrong. Do you think it'll make a big difference?

And just so I understand Fred's advice correctly, I put the entire muffler in teh fire, right? The pronouns in his advice are confusing, note that the "it" could refer to either the wire or the whole muffler and wire:

"To unclog it you need to get it real hot and burn it out... one way is to attach a coathanger wire to it and set it into the coals of a hot campfire... pull it out every 5 minutes or so to make sure it is not melting it... turning orange is OK... melting is not."

Re: unclogging the exhaust....

Yep! The whole muffler. Maybe the wire is for lifting it out of the fire and making sure it's not melting. Charcoal is HOT! You could melt it or warp it,so pay attention like he says. I did it a little differently but it's dangerous and I won't recommend it. Fred's way is the sure-FIRE way. Ha!

Re: unclogging the exhaust....

I would say screw it, and get a performance exhaust. They are cheap enough, and make a big difference. You might need to buy a bigger jet to go along with it, but those are only a few bucks.

Re: unclogging the exhaust....

By the way, how long do I leave it on the coals? Is it like a 5 minute thing or more like a half hour thing?

And after it has sat on the coals for awhile, I tap it with a hammer and prod it with a wire? Do I need to do this right away, or can I let the thing cool for a bit?

Re: unclogging the exhaust....

Oh,you'll see a lot of smoke,and when the smoke diminishes,cool it down and check it out.You could leave it in there a long time if you don't warp it.

Poke it with a wire ?

lol

Where do I say "poke it with a wire ?

I said... "attach it to a coathanger"... wire ... so you can place it in the fire and pull it out.

You aren't going to use your fingers I hope ?

###

To unclog it you need to get it real hot and burn it out... one way is to attach a coathanger wire to it and set it into the coals of a hot campfire... pull it out every 5 minutes or so to make sure it is not melting it... turning orange is OK... melting is not."

###

You set the MUFFLER in the fire... not just the coathanger.

You let it sit in there for a good while.... (if you have a true campfire with hot coals in it... it will only take 15 minutes in the coals... and pull it out once or twice to make sure its not melting.. the coathanger is there for you to pull it in and out)

And doesn't my instructionsa say to... "bang the ash out AFTER it cools" ?.... (as in -- don't bang on a red-hot piece of sheet metal... it will bend and deform like taffy).

Good luck.

Re: Poke it with a wire ?

Thanks Fred, sorry for the misread. Thanks to your stellar guide my moped is so close to perfect, I just didn't want to screw up this last step.

Anyway, thanks again for publishing that guide, it really is excellent.

Re: Poke it with a wire ?

david f martin /

On the bikes I've worked on, the exhaust port on the cylinder gets clogged up long before the muffler does, and the only way to thoroughly clean out the carbon is to remove the cylinder (so you can get to the port from inside and out). This makes a huge difference in the way the bike runs.

david

Re: Poke it with a wire ?

This from the guy who just put a brand new 2 stroke piston in backwards ?... even though it has an arrow on its top pointing the correct direction ?

You are lucky mopeds have small ports... otherwise it likely could have ruined the new piston and cylinder and rings.

But... YES... BOTH the exhaust port and muff should be checked... just like some guide somewhere recommends.

Re: unclogging the exhaust....

alternately, brians puch exhaust was pretty clogged up when he got it.. puch exhausts (unline, say, vespa exhausts) come apart pretty completely... we just took the whole thing apart (there is a little bolt inside you can access from the back) and used brake cleaner and a good little wire brush to scrape the stuff out... you may wanna try this before tossing it into the flames. once you scrub all the crap out of it, put it back together carefully and see how that works.

-casey

Re: unclogging the exhaust....

david f martin /

Fred, I probably did put that piston in backwards to keep the ends of the rings away from the damaged port. I did look for an arrow on top of the piston and didn't see one (I've built VW engines and know that the pistons are supposed to be oriented the right way)...

On my last bike (QT50), I mangled the muffler trying to clean it out (which it DIDN'T need) before I discovered how clogged up the exhaust port was.

I've been wrenching for over 20 years now, and I've made lots of mistakes, and tried to learn from all of them. If I offer anyone any advice, it comes from my own experience (and I'm no expert), not from something I've read somewhere. Don't consider it gospel, just an added footnote.

david

Re: Poke it with a wire ?

I have used easy-off oven cleaner with very good luck.

It is a pretty common trick with ysr50 racers(stock class)

It may not unplug your exhaust but it will remove oil,soot,and

carbon from the inside of the pipe.

cap one end of pipe and spray entire can of oven cleaner into

pipe turn pipe to coat entire inside and let sit for a couple

hours,then hose it out.

good luck!

Mangled it ?

Why on earth did you 'mangle it "?

If you attempted to cut it apart or something... thats just foolish.

It has been mentioned here about 300 times that the way you clean a 2 stroke muffler out is by BURNING it out.

No damage... low hassle... works perfectly... (and by the way is recommended in many service manuals)

If you had an oxy-acetylene torch.... that was the correct tool... put on the cutting torch tip (don't pull the oxygen trigger though)... and get the muff up to a glowing red all over... then place the torch in the muff inlet.... the interior will be back to bare metal with the internal holes the size they were the day it came off the assembly line.

(its in the guide)...

Re: Mangled it ?

david f martin /

At the time, I was working from what little knowledge I have of VWs and 4-stroke motorcycles. 2-strokes have some major differences as far as fluid dynamics are concerned. I wish I'd seen your guide before I cut my muffler apart (at the very least, I wish I were a better welder!).

I don't know why you're stepping on my toes, Fred. I was only offering my experience on a specific problem, not trying to usurp you as Guru Of The Mopeds.

david

freds advice site?

Ben Phillips /

wat is the address to fred's advice site

Re: freds advice site?

Click on `resources' and find Fred's guide `How to fix your Moped'.

Re: freds advice site?

I shoulda' added to click on `articles after you click resources,Ben! Sorry!

Re: Hurt toes

Fred can step on anyone's toes. That's a given.

After what you did to your muffler.... jeez, just about anyone would have tooled on you--- Fred just went there first.

He is the expert, and I've never heard of anyone cutting their exhaust open to clean it.... hehehe....

I laugh, because it sounds like something I'd have done before I found this site.

Fred meant no harm, he just thought it was funny that you cut open your exhaust----- !

Be careful, Dave, we might nickname you the "Muffler Mangler" and you know how nicknames are--- the more you hate them, the more they 'stick'.

Jokingly,

-Wayne

Re: Mangled it ?

Dave, you handled that better than I would have....I get super pissed when people act like I am a moron. Specially when you are just putting in your two cents, which you have a right to do. :) Fred...Don't hit me. Haha.

Chris

Re: Mangled it ?

david f martin /

At the time, I'd read that there were mufflers you could take apart, and mufflers you had to cut apart to clean. Also, I was getting advice from local yokels, "Yeah, I used to have one of those. I fixed mine so it would run 60mph!"

Being a bartender at a biker establishment in the evenings at the time, I knew that the first thing the Harley shop sold these yuppie biker wannabes was a straight exhaust, sans muffler, to make it go faster and louder.

So, after I mangled my muffler, I cut it off the exhaust manifold (I know that's not the proper term for a single cylinder exhaust, but proper term escapes me at the moment) and welded in a straight VW tailpipe. If you look at the pics of my bike in the photos section, you'll see it. Made perfect sense to me at the time, but it didn't work very well. Works good on VWs and Harleys, but not mopeds.

I've been working on VWs for a little over 20 years now (the past 3 years professionally), and I answer the same questions over and over again, so I understand how frustrating it can be sometimes, but that's why I'm on one side of the counter and my customers are on the other. If I treat them rudely, they're going to take thier business elsewhere.

If everyone knew as much about VWs as I do, or about mopeds as Fred does, we'd both be out of a job. Neither of us knew this stuff when we were born, and I'm sure we both have learned some of this stuff through trial and error. At one time, we were the ones asking the same questions everyone else has asked.

We had a Guru on the VW type2 list (early microbuses) who was a cranky old man, and after awhile, folks quit asking him questions, and he just sort of faded away and disappeared. I don't know what he's up to now. Probably sitting drunk and lonely in front of a computer screen in a dark room, wondering what happened to all his friends...

david

Re: Mangled it ?

So, you like the nickname?

Yours,

Wayne

Re: Mangled it ?

david f martin /

"The Muffler Mangler"... Hmmm. Has a nice ring.

david

David, VW Question

Ron Brown /

David,

A friend of mine is moving. He used to own a Porsche. He has a box of parts, including the original Porsche Delorto's, complete with K&Ns (he put Webers on the car), New, in package intale manifolds. They look longer than normal, he doesnot remember why they were not used. For an encore, a used, but looks good to me, oil sump capacity increaser. Sort of a cast aluminum finned shell that estends from the bottom of the sump.

Do you know anyone who may be interested in this box of goodies?

Ron

Re: David, VW Question

david f martin /

What type of Porsche (911, 914, etc.)? How much does he want for it? I'm not interested, but I know a few Porsche folks who might be.

david

Re: freds advice site?

i still cant find freds advice site.. domsone put a hyperlin on

Re: freds advice site?

Hey man... see this page you are on right now ?

Look up at the top... see "Resources" ?... click it

When you get there... find ..."Articles".... click it

When you get there... find .. "Freds guide to Fixing yer ped"

(or something like that)

IF thats all too hard <IMG src=" http://www.cycleworld.com/ubb/NonCGI/rolleyes.gif"> ;.... click on this

http://www.mopedarmy.com/resources/articles/10/

Re: David, VW Question

Ron Brown /

Dave,

Thanks, I think they have been sold, but if not, I will get more specifics.

Ron

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