MXS GP90 Build

[Lucass2T]

Nice setup!
Imagine how much it would hurt blowing up that motor lol.

[pewpew]

Mar 30, 2021 6:17:15 GMT -5 twostroker said:

Very nice parts, i have the same setup on my aerox except the cylinder and crank

[twostroker]

Mar 30, 2021 7:28:20 GMT -5 Lucass2T said:

Nice setup!
Imagine how much it would hurt blowing up that motor lol.

It does hurt to think about lol. I’m a little nervous about the first start with the pwks jetting to be honest. Hopefully as long as I start super rich, I will be okay. I have already been looking at spare cylinders and pistons, just in case.

If I seize this thing I will probably spend the day😭😭 lol

[twostroker]

I installed the MVT inner rotor ignition and set timing to 0.0138”BTDC with the help of the 49ccscoot YouTube video. I have watched the TPR 86cc series several times. If you haven’t watched it yet, there is very helpful information in that series and other playlists with videos covering about anything you could imagine related to scooter tuning.

This build wouldn’t be possible without the help of this forum and the YouTube channel. I have referred to them both every step of the way so far.

I’m fairly confident that everything sealed properly. I will try to put a pressure tester together after work today to ensure that it has no air leaks. The sealing plugs use two O-rings each and permatex to seal. That is the area I’m most concerned about.

I will post the results of the pressure test after work. Wish me luck.

[twostroker]

Finally pressure tested this weekend. Had a massive leak at the rubber intake and reed spacer. Fixed that and found a huge leak at the cylinder base. The side I built up with jb weld was fine. Apparently, the transfers hang off the mounting base on the cases on both sides. So I removed everything and am building both sides up with epoxy so I can get it to seal.

I destroyed my base gasket in the process and nowhere has them in stock. I will be looking for some gasket material to make my own.

[captincvmn]

Cereal boxes are great gaskets depending on pressure requirements

[190mech]

Gasket Making;
49ccscoot.proboards.com/thread/2250/base-gasket-spacer-fabrication

[twostroker]

I’m still having trouble posting pictures from iPhone. Anyhow, I got some more parts in.
Got a mount made for the yz125 radiators.

Waiting on parts for wiring. Also waiting on gasket paper and hondabond to hopefully seal this cylinder base.

La Furia Rossa cvt came in. For some reason I was expecting it to fit a 16mm crankshaft. So I will have to get the hardware to covert from 13mm to 16mm. I wonder if the MHR 16mm conversion at scootertuning.ca is the same variator?

Once I get everything sealed, it won’t be long until she’s on the road. I went with a Motoforce 32mm pwk for a carb.

[captincvmn]

On my iPhone I go to the bottom of the page and click “desktop version” and then the menus are different. The reply or post window has an add image right above the text box.

I did just download the Tapatalk app and that makes it easier to post pictures on mobile but I think it’s harder to track what messages are current. Up side is new messages are pushed to your Lock Screen.

[twostroker]

I finally got it started for the first time this morning. It’s still super rich in the video. I’ can’t wait for my variator and new water pump to come in so I can ride it!!

Check out the video:

youtu.be/vCE4TmBiHbI

[twostroker]

[twotoker]

youtube.com/shorts/vCE4TmBiHbI?feature=share

[twotoker]

There’s a video of the first start, obviously rich. That 90cc scooter was so fast it was scary!
Unfortunately everything but the motor was stolen. I’m hoping I can find a Zuma frame to bolt the crankcase to.
I have a couple of extra 90cc cylinders I may list and if I don’t find a frame, I may list everything left on the engine.

[pete130]

Mar 24, 2021 18:30:50 GMT -5 twostroker said:

That is a Polini Big Evo reed cage and a Most 25mm 5 degree spacer. I was going to use that setup but could not find an intake compatible with the 30-38mm carb MXS recommends. I finally found a MXS intake kit with kx85 reeds at scooter swap shop. It will accept the larger carb.

I’m considering a 34mm since that’s what was on the setup on YouTube that made close to 30hp. I’ve never ran anything larger than a 21mm delorto, so I am nervous about tuning the pwk I decide to go with. I’m looking at the Stage 6 pwk’s. I will definitely be asking for some advice when the time comes to tune. I always start super rich. I read yesterday that pwks will run fine even if they are running lean.

Tomorrow I am expecting a shipment from Maxiscoot. I will be getting:
MXS GP90 exhaust
MVT Digital Direct
Str8 Water pump
Lots of odds and ends for liquid cooling
Quick action throttle
16mm variator small parts

MXS intake should be here Friday.

All that’s left to get is
Stage6 PWK
YZ125 radiators
Stage6 Oversized CVT
Clutch and Bell
Temp gauge
Tachometer
I’m sure I’m forgetting a few small things.

Sounds like a killer build I haven't been posting much in the last year or so im In to high out put motors as well I have looked at the gp90cc kits they are a great kit, here's my 3 port exuarst 35mm header

[808ministroke]

Jul 24, 2022 17:24:19 GMT -5 twotoker said:

There’s a video of the first start, obviously rich. That 90cc scooter was so fast it was scary!
Unfortunately everything but the motor was stolen. I’m hoping I can find a Zuma frame to bolt the crankcase to.
I have a couple of extra 90cc cylinders I may list and if I don’t find a frame, I may list everything left on the engine.

That's FUCKED dude I feel for you and really hope u find a frame so you can enjoy all the hard work u out into such an awesome build. I'm rooting for you.