Project 90 (Stock 89cc And Beyond)

[2strokd]

Very informative! Thats gotta be the most technical yet.

[90GTVert]

Nice, someone is paying attention. lol That took about 15 hours of work (granted, it took me a while to figure out how to do multiple screens for vid lol), $50 in sliders, $5 in gas, and no one had replied. It's very good just to know somebody looks at it at least. ;D Thank you.

[shakerdriver]

That is alot of info to read and pick out certain things that may help each individual, but thanks for the time to put it all together Brent.

[lshigham]

Nice work Brent, almost makes me want to buy a big block mina and a an aprilia rs50 to put it in. Oh wait - I'm skint :rofl:

[shakerdriver]

Thats what I'm planning on doing with the rs50 Ditech I got from 2strokd Luke.

[johnnyshere]

all your threads are detail oriented i enjoy reading them. i never had anything to add. i spent 2 days here just reading threads lol

[jonik]

Nice work!

Gas price is huge here right now. Cheapest 2,3$ per liter. And it's increasing. 15 years ago it was half that.

[lshigham]

I can remember the good old days of $1 a litre petrol and I'm only 17

[190mech]

Great thread Brent!Everyone interested in a 2 stroke scoot should read this!The 90cc is THE best performance upgrade,and if one follows your reports,they'll surely have a nice machine!! :thumb:

[90GTVert]

OK, there are more people watching than I thought. Didn't mean everyone had to post, just was getting discouraged for a moment. Thanks though.

I remember under $1/gal for high test. Before then I couldn't drive so I never really paid attention. :dunno: I started driving in 1995.

[190mech]

Heck,I remember the "gas wars" in the 60's at 29 cents a gallon!That was real gas back then,we get crap now!!

[90GTVert]

Modified Stock Exhaust


Next up, I'm gonna try out a few exhausts. I'm starting with a modified stock pipe. This is the exhaust that came on my 90cc Triton, that I modified as shown HERE.








I had some hope for this pipe, mostly because I noticed the 49cc stock pipe that has been on Project 90 was discoloring from heat. I thought perhaps that could be a sign that it was too restrictive.





I installed the exhaust and immediately did a plug chop, then took a short ride to see if anything seemed off. No tuning was necessary. I went for a longer ride that night. Fuel mileage was 38.6MPG, the lowest to date with this project. I was pretty easy on the throttle, but I did have to fight some fairly strong winds at times. Max speed was 51MPH. I tried to avoid getting help from a tailwind, but I may have had some assistance.





It appeared to me that power may have actually dropped slightly at higher RPM slightly. I'm not sure if it could be header length, internal design, better matching of the port to the pipe, or what for sure. All I know is that I would greatly prefer the ever so slightly better performing, quieter, unmodified pipe.

[190mech]

The stock pipe looks like an engineered piece,the other looks like the stylists in the art dept. created it!

[90GTVert]

Well, I was thinking the same thing... but I'm always afraid to draw too much into anything made in China. lol The one from my Triton (modded) uses the exact same muffler as some 150cc 4Ts and probably some 50cc 4Ts. I know it's the same as some of the larger GY6 mufflers, because I've modded one for a friend. I think they made it a multiple piece design so they could mass produce mufflers and then just swap headers and brackets for each application. Here's the GY6 150 muffler just like it, modified.

[190mech]

Yeah,The bean counters figured 1 muffler would fit a bunch of models,heck with performance,just more sales is what matters!