Cleaning out exhaust
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Addicted
'76 Vespa Rally 200
Joined: 13 Feb 2011
Posts: 549
Location: Melbourne
Wed Aug 07, 2019 7:34 pm quote
I'm looking into some performance issues with my Rally that have cropped up lately. Torque is lacking in 1st and 2nd, hold the throttle at a certain point and you can feel power varying. I'm going to look at the carb and jets first, I've never touched them in ten years of ownership, and in the last 18 months the scoot has only been used a few times.

But I'm also wondering whether I should clean the exhaust. It's a Polini expansion pipe style, and probably has never been cleaned since it was put on 15+ years ago. But I didn't find much talk about this on this forum. Do any of you ever clean your exhaust? I've seen videos of people doing it with a heat gun, torch, or BBQ, but I live in an urban area with houses all around, so I don't really want to use those methods and create a cloud of oily smoke over the neighborhood.

Ginch loaned me a lightly used performance box exhaust, so I'll pop that on when I get a chance and see if it makes any big difference.
Ossessionato
LXV 150 3v ie. Midnight Blue (Sold)
Joined: 06 Dec 2010
Posts: 2999
Location: Bangkok
Wed Aug 07, 2019 7:39 pm quote
Cautic Soda is a DIY method but oxy-acetelene or oxy-propane is probably the best.

Or put it on the barbecue.

You will need to repaint it afterwards! if choosing the burning out method with oxygen as it gets very hot.

If never tried the hot air gun method.

Or a combination? Put it on the barbecue to preheat and then use the hot air gun?

https://www.youtube.com/watch?v=9TL8cUhdYu4
Ossessionato
73 Rally, 74 Rally, 76 ET3, 80 P200, 63 Li125, 65 Li225 Silver Special, 86 Elite 80, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 3283
Location: Oceanside/ SF
Wed Aug 07, 2019 9:27 pm quote
If thereís any aluminum in the pipe, dont bbq/bonfire it. Itíll melt that aluminum in no time.

If youre worried about the neighbors, torch it at night. The flame/smoke coming out of it will be a little black but will fade out no problem. It not going to be a house fire sized black smoke cloud caused by you burning car tires or anything. If i remember the last few exhausts only burned for like 10 minutes and then it was done.

If you hate your neighbors use it as an excuse to have a little fun. Play devil music and make goat sounds as you fill the skies with flames!
Ossessionato
LXV 150 3v ie. Midnight Blue (Sold)
Joined: 06 Dec 2010
Posts: 2999
Location: Bangkok
Wed Aug 07, 2019 10:14 pm quote
MJRally wrote:
If thereís any aluminum in the pipe, dont bbq/bonfire it. Itíll melt that aluminum in no time.
What he said.
Molto Verboso
08 GTS 250, 79 P200E, 62 Allstate
Joined: 11 Jan 2006
Posts: 1314
Location: Florence, OR
Thu Aug 08, 2019 8:30 pm quote
MJRally wrote:
Play devil music and make goat sounds as you fill the skies with flames!
I was cracking up at this one...
Hooked
1955 Allstate 1958 lambretta 1965 Allstate 1968 sprint
Joined: 20 Jul 2017
Posts: 397
Location: Central california
Fri Aug 09, 2019 11:27 pm quote
Exhaust
I bbq the shit out of two of my pipes and they didnít smoke much at all. 500 degrees for almost an hour. One of the pipes I cut in half just to make sure it was clean. I than proceeded to modify the pipe. Worked well.....not much smoke....or at least not to worry about.
Devil music and goat sounds works for me too.
Hooked
lml 2t Vespa lx50 2t
Joined: 21 Jan 2018
Posts: 142
Location: wales
Sat Aug 10, 2019 3:25 am quote
Out of curiosity can any of the above be used on a catalyzed exhaust. I have done it on normal one's over the years but not the cat types
Thank you
Molto Verboso
Vespas 1964 GS160, 1965 SS180, 1977 V9A1T, 1983 PX150E
Joined: 16 Apr 2011
Posts: 1150
Location: Siam
Sat Aug 10, 2019 4:27 am quote
qascooter wrote:
MJRally wrote:
Play devil music and make goat sounds as you fill the skies with flames!
I was cracking up at this one...
Shit, so was I.
Addicted
'76 Vespa Rally 200
Joined: 13 Feb 2011
Posts: 549
Location: Melbourne
Tue Aug 20, 2019 3:27 am quote
Lucky me, the neighbors in the house behind mine just moved out. Now could be a good time to try this.

Would regular propane be good enough? I'm not buying an oxy setup for this, but I have a propane torch. And a heat gun, but I'm not sure about running that continuously for 10 minutes.
Enthusiast
P Series / Li / LML / Motobi
Joined: 24 Jun 2019
Posts: 96
Location: 3rd Rock From the Sun
Tue Aug 20, 2019 4:13 am quote
if its hot enough to get smoke out of it then yes..... just keep "burning" till the smole clears.. then give it a good tapping all round and a shake to get the solids out and off you go
autojack wrote:
Lucky me, the neighbors in the house behind mine just moved out. Now could be a good time to try this.

Would regular propane be good enough? I'm not buying an oxy setup for this, but I have a propane torch. And a heat gun, but I'm not sure about running that continuously for 10 minutes.
Hooked
1974 Vespa 125 Primavera, 1980 Bajaj Chetak, 1962 Lambretta 175TV3, 2006 Yamaha Vino
Joined: 07 Jul 2017
Posts: 431
Location: Boston, MA
Tue Aug 20, 2019 6:15 am quote
I have not had luck with the heat gun method. Spent a long time burning out a pipe and was convinced it was clean. It was then placed on a campfire and continued to smoke for about an hour.
Hooked
1955 Allstate 1958 lambretta 1965 Allstate 1968 sprint
Joined: 20 Jul 2017
Posts: 397
Location: Central california
Tue Aug 20, 2019 11:25 am quote
Exhaust
BBQ it up....
Addicted
'76 Vespa Rally 200
Joined: 13 Feb 2011
Posts: 549
Location: Melbourne
Tue Aug 20, 2019 2:17 pm quote
Re: Exhaust
Sjanuary wrote:
BBQ it up....
I only have a small gas grill, even if the pipe could fit in it, which I'm not sure of, I think I'd rather not cook an exhaust in the same place where I cook dinner! If I had a charcoal Webber I'd probably be ok using it.
Hooked
1974 Vespa 125 Primavera, 1980 Bajaj Chetak, 1962 Lambretta 175TV3, 2006 Yamaha Vino
Joined: 07 Jul 2017
Posts: 431
Location: Boston, MA
Wed Aug 21, 2019 5:21 am quote
Re: Exhaust
autojack wrote:
Sjanuary wrote:
BBQ it up....
I only have a small gas grill, even if the pipe could fit in it, which I'm not sure of, I think I'd rather not cook an exhaust in the same place where I cook dinner! If I had a charcoal Webber I'd probably be ok using it.
Know anyone with a back yard fire pit? Any local campgrounds or recreational areas with fire pits?
Veni, Vidi, Posti
a not so normal vbb2 '64, a weirdo vbx '86 and a not so normal pts100 '82
Joined: 15 Jun 2009
Posts: 5488
Location: Indo
Thu Aug 22, 2019 4:09 pm quote
i have mango tree, and in this summer i can collect all the falling dry leafs and burn it along with the gunked pipe
Addicted
'76 Vespa Rally 200
Joined: 13 Feb 2011
Posts: 549
Location: Melbourne
Thu Aug 22, 2019 9:12 pm quote
Holy crap! With the BGM box that Ginch loaned me, the scooter practically flies!

I'll try cleaning out the Polini pipe, it'll only cost me a propane bottle. If it doesn't help, maybe time to bin it and just spring for a BGM or SIP Road.
Member
2011 Vespa LXV150ie
Joined: 22 Aug 2019
Posts: 29
Location: Kokomo, Indiana
Fri Aug 23, 2019 8:58 am quote
I worked as a small engine mechanic for 20+ years before getting hired at the local FCA plant. The way I would clean out 2 stroke mufflers that were plugged up with oily gunk(especally Lawn Boy push mowers!!), would be to pour some gas inside the muffler and let it sit for a few min to soak in, then light it on fire with my propane torch, while standing away from it as far as I could.(muffler is sitting on the ground either on the gravel drive or concrete drive away from the house/shop) It would flame and smoke for awhile. Once it was out, I could tap it with a small hammer lightly to knock the ashes out. I could then clean it up, repaint with high temp paint, and reinstall on the mower. Same would work for a Vespa muffler. Mike
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