Peugeot 103 decompressor removal

This is a quick little modification to a head for my Peugeot 103. The volume of the decompresser chamber is fairly large on these heads. So it seems like in the end you end up reducing the compression ratio a pretty good amount with the stock head, at least thats what it seems like to me. So I tried a little experiment on this malossi head. I tapped and inserted a set screw in the exit port from the combustion chamber to the decompresser valve. I also filled exterior port with a plug as well just to make sure it's completely sealed up all the way.

Re: Peugeot 103 decompressor removal

Nice work

Re: Peugeot 103 decompressor removal

Thanks Steve, guess we will see how much more of performance boost I receive from this.

-Naz

Re: Peugeot 103 decompressor removal

Sorry for the crappy quality of the photo, but this is the stock head that came off the bike and the decompresser volume is fairly large. I will try to grab a better photo later on, but just in case anyone wanted to see a side by side difference in the amount of volume in the combustion chambers.

Re: Peugeot 103 decompressor removal

my malossi head doesnt have anything for the decomp setup. interesting.

Re: Peugeot 103 decompressor removal

The combustion chamber on the malossi is super nice, the only thing I was not impressed with is they left burrs on the hole drilled for decompresser assembly. On most engines that detonating waiting to happen... or possibly the little pieces might flake off and damage something else :-/

-Naz

Re: Peugeot 103 decompressor removal

I'm not sure that will add much, but good luck!

Re: Peugeot 103 decompressor removal

There is a larger volume then what you see in the photos, there is a chamber inside the head where the port from the combustion chamber goes into and would normally have the decompresser assembly in it. Yeah other wise I wouldn't have bothered :-). It would add about another ~1/3 of the total volume to the combustion chamber.(uh that was kinda worded weirdly but hopefully it makes sense)

-Naz

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