Project 90 (Stock 89cc And Beyond)

[90GTVert]

Well, the next mod was gonna be an Arreche 19mm carb. I guess I don't know my own strength though, because I snapped the atomizer re-installing it. I know better than to ovetighten anything in a carb... or I thought I did. Ordered a replacement. $8 for the part, $12 for shipping.

[lshigham]

Ouch, that's some expensive shipping

[90GTVert]

Sad part is that it's from right here in the US, even on the east coast from Moped Hospital. It's the only US seller I saw with parts in stock for these.

[lshigham]

Got some stuff from Scooter Attack in today, the shipping for that was the same as yours for some carb bits and the box was huuuuge!

[90GTVert]

I had really good luck with them ordering Arreche jets on my first order from them ever. After that they took a really long time and charged me way too much for shipping so I haven't risked it since.

[90GTVert]

An update will be coming soon, but in the meantime here's a duck trying to hit me in the face. lol Didn't look close in the vid, but I assure you it wasn't too far from my head. I was more worried about the duck than me.

[2strokd]

that coulda took your head right off man....

[90GTVert]

Reed Spacer


Reed block spacers seem to get very mixed reviews. Some opinions I've read feel like it serves no purpose. Others believe it works. I think, like most other mods, the effectiveness depends on the application. The best I can do is give you an honest review and let you decide for yourself if you wanna go for it.


The reed spacer I'm using is a simple homemade version, made from an old spare reed block. With an extra gasket it ends up being about 4mm thick. You can find all of the details to make your own HERE. They are also available from many sellers for around $15-$25 in varying thicknesses and made from different materials.




The spacer is placed under the reed block to raise the reed assembly out of the intake tract a little more. This is said to increase throttle response and low end power. This mod will increase the volume of the crankcase and therefor lower primary compression.


One effect that can easily be seen is unblocking the boost port. Well, it's easily seen if you just happen to have an extra set of engine cases around. ;D Notice the reeds protruding into the boost tunnel in the first pic with no spacer, then clear when the spacer is used in the second pic. The boost port on the cases shown here has been modified, so the intrusion may not be as drastic on stock cases and cylinders.






Here's another view of what's happening inside the cases.






Installation is simple. Just make sure there are no air leaks. The reed blocks on Minarelli/Jog motors is a common spot for sealing problems. I use an RTV sealant to avoid problems when installing reeds. You may need longer bolts depending on the thickness of the spacer.




No jetting change was necessary. It worked fine with the 85 main jet and the needle set in the next to richest position.


I went for a 36 mile test ride to evaluate the change. On the trip I had a max speed of 51MPH. Fuel economy was 45.9MPG. It didn't seem like it was as willing to rev out as without the reed spacer. It felt like the powerband may have moved down just ever so slightly to me. I can't honestly say I noticed any difference in low end power output. Any changes in peak power would be very slight.


I did notice two good things with the reed spacer in place. The throttle response improved. That was the most obvious change. Nothing crazy, but there was definitely a difference. I also believe the engine ran a little more smoothly. It felt like more of a smooth transition throughout the rev range or throttle position than before.


I would gladly do this mod to any of my Minarelli powered scooters. It may not make any big improvements, but it's cheap, simple, and just feels right to me. Who can't use a little more throttle response? I think with ported cylinders and cases moving the reeds up might have a slightly more pronounced effect than on the small ported stock setup.

[190mech]

I agree,the spacer is a good first item when more power is to be made..
Love those new camera setups also!! ;D

[90GTVert]

Thanks. It's actually a roll bar mount that I got to use in my car (if it ever runs again) and since T2 is all steel tube it works out nice. ;D

[90GTVert]

Carbon Fiber Reeds


This engine came with a set of carbon fiber Malossi reeds when I picked it up on eBay. Of course I promptly removed those performance parts to go stock (that still sounds wrong even this far into the project). Now that I am trying out some other intake/reed related stuff, it's time to see if putting them back on will show any benefit vs the stock metal reeds.


The install is easy enough. Just remove the screws, stops, stock reeds, and backing plate to start.






Here's a pic to sorta show you the order it goes together.




Stock steel reeds vs Malossi reeds.




Assembled.




You may notice that I have the words out on one side and in on the other. It really doesn't matter unless the reed is curved. Sometimes aftermarket reeds are made curved slightly so they naturally press into the reed cage to promote sealing. In those cases I believe the writing should be facing out. For these, I just tried each read on both sides and mounted however they appeared to seal the best. The easiest way to see if they are sealing is to look for sunlight coming through the reeds.




No jetting change was necessary so the setup is using an 85 main jet with the needle in the position next to the richest.


I took a 19 mile test ride and observed 45.9MPG. My max speed was once again 51MPH on the GPS. It appears to me that the reeds are making no difference. Cruising speeds were the same as the stock benchmark again, low to mid 40s. There may have been a slight change in throttle response and smoothness, much like the reed spacer, but very slight.


One common reason for swapping to carbon fiber reeds is that they put your engine at less risk if they break compared to the stock steel reeds. Perhaps they would be worth adding for that reason, but if you are looking for more performance from your stock 90cc I think you'd be quite disappointed in this mod.

[90GTVert]

Polini Reed Cage


Even though I didn't have much hope for improvement after the other reed related mods, I thought I might as well finish it off and try out the Polini reed block with carbon fiber reeds that I have on hand.




Here's the difference in port area of the Polini (left) vs stock.




I installed the reed block with the stuffers thinking that would be the best setup for the stock setup with it's small carb and small ports.




With the reed out, you can see how the stuffers smooth out airflow through the reed block.




As with all of the other reed mods, no change in jetting was necessary. 85 main jet, needle clip next to the richest position.


On a 38 mile ride I got 46.8MPG. Max speed was 51MPH. This mod felt similar to stock and the carbon fiber reeds in the stock block. Little to no changes. Possibly a change in throttle response. It didn't even seem like it ran as smooth as with the reed spacer or the Malossi reeds.


I'd probably only do this mod in preparation for bigger things to come or if there were a problem with the stock setup and I could get a good deal on an aftermarket cage. I will also note that the Malossi blocks I have in other scoots are better quality than the Polini block.

[90GTVert]

Well call me Mr. Butterfingers...



Dropped it in the floor while replacing the bulb that blew when I had rectifier troubles.

[Thebatman]

HEy man, thank you for such a detailed explanation on this build. I would say it's gonna be priceless for many ppl.... ;D
:cheers:

[90GTVert]

Thanks for watching! ;D