Anyone modify stock puch exhaust baffle?

I just got my 77 puch maxi running, the exhaust seemed very restricted. After removing the stuborn baffle, I found it was very dirty/clogged. I soaked it in overnight, then ran it through a steam cleaner. I got it almost back to original condition and exposed some holes that were completely blocked. I have not got it back together yet to compare power. My question is: has anyone modified it by adding more holes, etc. I saw a reference to an old post where someone had done just that, but couldn't find any details. It seems even with it clean, it could use a little more "breathing room"

Re: Anyone modify stock puch exhaust baffle?

I know people drill the little restricting tubes out of the header, but I dunno about the baffle.

http://www.mopedarmy.com/resources/articles/maxi-derestriction/

Re: Anyone modify stock puch exhaust baffle?

You need to have that back pressure for the bike to run correctly. I've modified puch pipes, and have even gone extremely fast on them (They start to whistle when you hit 45+), but you will loose most of your low end by modifying the baffles. There are other ways to make a bike fly without messin' with the baffles or buying preformance parts.

Re: Anyone modify stock puch exhaust baffle?

Thanks for the replies! I have a feeling just cleaning the baffle should help some, it was VERY dirty. If it seems like it needs more, maybe I'll consider drilling out those restriction pipes (thanks for the link).

Re: Anyone modify stock puch exhaust baffle?

The restriction pipes do make it a lot worse. You need to clean all of the carbon out of it.

I forgot to mention this:

I've had decent results with this, but you might not get everything lined up correctly. It helps if you use your bike to hold everything at the correct angles as you work.

1)Take the header out of the pipe chamber.

2)Cut the header at the end of the flange (right after it enters the chamber) Throw out the chamber side of the header pipe(side with the threaded rod thingy).

3)Make sure the connection is tight (with the gasket in place)as you'll only be able to do this once: Use a self tapping metal screw to hold the header to the chamber and trim the screw so it is flush with the interior of the header.

4) use a self tapping metal screw to hold that little metal tube in the baffle.(you don't need the washer and nut that normally go on the end anymore)

5)Use another self tapping metal screw to hold the baffle in the chamber (from the swingarm side of the chamber so nobody can see it)

Re: Anyone modify stock puch exhaust baffle?

how do i remove the baffle?

Re: Anyone modify stock puch exhaust baffle?

you take the nut inside the end of the pipe off and the chamber comes off. theres an exploded diagram of the stock pipe here:

http://www.themopedjunkyard.com/puchexhaust.html

Re: Anyone modify stock puch exhaust baffle?

i took off the bolt at the end but it will not come off.

Re: Anyone modify stock puch exhaust baffle?

i'm about to work on my baffles today. I'll let you know how it works out. mine's a 1980 puch sport mkii

Re: Anyone modify stock puch exhaust baffle?

I opened up the holes in the baffle and cut a lot of the tubing out of the expansion part. The easiest way for me to explain it is that I cut notches at the flange on the top and bottom and then two past the holes and then cut parallel to the pipe so as to connect the notches. This results in about 80% of the pipe gone and so there are two runners connecting the rest of the exhaust but allowing it to act as a expansion chamber. I chamfered the opening at the flange as well. This plus a very lite porting changing the timing resulted in a +6 mph increase and a good bit more torque down low. The pipe is definitely holding it back but not as much as it was before and with more porting it could be faster but I would loose torque.

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