Honda Spree and Elite 50 Forums

GSX1400 wrote:Hi, i find it strange to put the silencer in the middle of the exhaust??? Never seen this before. Always seen the silencers at the end of the cone? Is there a reason for this design? The pipe IS empty inside?
Just out of curiosity (I ride an Aero50...in France!)

It's not the first time it's been done. Couldn't tell you the reason that it's an advantage from an operational standpoint, but the overall package is smaller / shorter. Goped exhausts are often built this way... here's an example:

It seems like the exhaust exit bing in the middle of the exhaust would allow for more of the chamber to be used?? I.E. exhaust must first bounce off of the rear of the chamber before making it back to the center of the chamber to be able to exit, seems like it would give the effect of a longer chamber moving the powerband? I could be wrong and maybe its just for looks or to make it a bit smaller, but from my goped pipes I can say that a center exit pipe compared to an end exit pipe , the center exit seems to make power in a different rpm range and hit a little harder. (those that have rode gopeds will know exactly what I mean by "hit")

I cant remember which company made them but there are some rare aftermarket expansion chambers almost exactly like this that were made for the Spree with the silencer in the middle. Taz bought it from a guy on this site that got it on a Spree he had bought.

I think KeithW's pipes were made this way... had forgotten about that.

I have chosen someone to test the pipe, thanks for all the emails and great comments! When the silencer comes off the dwell section it's call a side bleed. I use this design for many reasons, the main one being performance. A 2t pipe works largely on sound waves and the reverberation of them. On a standard exit pipe up to 30% of the useful waves exit the pipe as noise. On a side bleed almost 100% of the waves are contained! This helps to "stuff" the cylinder and give a much more pronounced power band than traditional chambers. Side bleed pipes are also significantly quieter and almost never need the packing replaced.

I plan on making Elite pipes once I get my hands on one.

I am looking forward to making a pipe for the 48mm bore kit for the Spree. I need some info before I make a prototype. Does anyone have a port map, pictures of the head and common modifications made to it? Does the stock Spree pipe bolt right up to it? And what is the desired power band low, mid, or high?

I did some test runs with the new pipe today and WOW this thing is awesome! I literally just bolted the pipe on, no other modifications at all, stock air box and all. Top speed prior to the pipe was 28MPH and now 35MPH! The pipe hits at around 15MPH and rockets the bike up to 35MPH. I know that with a high flow air filter and larger main jet I will easily see 40+MPH!

Could you do a video to give an idea of the noise level?

The 48mm big bore kit has the same exhaust flange position as the stock cylinder. The stock spree pipe does fit it.

Great, thanks!

Goodstuff. Ive have an 86 NQ50 and would love to buy one when you start selling. Looks good!

Motion Left Mopeds wrote: I am looking forward to making a pipe for the 48mm bore kit for the Spree. I need some info before I make a prototype. Does anyone have a port map, pictures of the head and common modifications made to it? Does the stock Spree pipe bolt right up to it? And what is the desired power band low, mid, or high?

I did some test runs with the new pipe today and WOW this thing is awesome! I literally just bolted the pipe on, no other modifications at all, stock air box and all. Top speed prior to the pipe was 28MPH and now 35MPH! The pipe hits at around 15MPH and rockets the bike up to 35MPH. I know that with a high flow air filter and larger main jet I will easily see 40+MPH!

Above describes about what the pipe I built does. Engine is blah up to 15 MPH then it takes off. Spree has 1 gear... I think that the sweet spot is making power in midrange. With a side exit you can make the pipe longer which will bring down the band. The 25mm downpipe will help alot, esp with the larger piston/jug available aftermarket. Stock is 19mm, which is really too small.

Port timing is listed in the service manual... from memory the exhaust port is 225mm^2. Too small for a 50cc bike, and timing is overly conservative. Lifting the exhaust port timing by a mm or 2 is reported to help.

There are 2 versions of the head and dished and domed pistons. There are pictures on this site of the different head designs. Most common mod to head is to mill .020" off the head to increase compression and create squish. Ditching the dished piston for domed is popular as well.

one other grope of scooter you may want to do is the se50 motor ...
swimmingfree

I get the same gains from the my sample that looks like the first muffler pic you posted. It gains about 6mph on stock and about 5-6mph on the 48mm BBK, carb, and gears. It is a nice add. How much you gonna sell those pipes for? I will sell mine for about 125$ and they will be available this spring. I would love to test that second model you have or are they the same pipe? It looks kewl. Looks like the one I got already.

The muffler I have have is set up for mid to high which I like. Also the noise level is not to bad.

Taz

The port map of the big bore kits will decide what chamber I use, but I will likely be using my Cali chamber with a side bleed on it. It's great for single speed motors! The picture is a Cali pipe I make for Puch Magnum mopeds.

If the price is reasonable, I'd be interested in a pipe.

I ordered the NC50 express MLM pipe, I just put it on tonight, and it feels like Im going to light speed when I grab the throttle and blast past cars. The pipe hits pretty early and dont stop giving and has even more pull when I get past 35mph like a good swift kick in the *. It comes on so hard its scary and I love it. I almost fell off the bike on the first test run hen the pipe hit. I havent stopped giggling all night lol