2009 Apex Mxr 90

[wickestangwv]

Just picked one up for my son. It had cracked transmission case when i bought it. They guy before me also had taken it apart. Does anyone have a repair manual that will show me with how to put this thing back together with new cases? Any help will be greatly appreciated.

[mmsoup]

It's a scooter motor, Minarelli Horizontal Short. If you have split cases before it's a snap. There are numerous opinions on the next subject, but we DO NOT use the transmission tunnel bushing that ships with Apex. We go to a Kasea style needle bearing (kaseaparts.com) Skyhawk 90 and we use the case saver. We don't race MX so we don't use a slipper clutch but MaxRPM has a nice slipper clutch that will save the tranny in the long run if you are on MX tracks. You can get the slipper from G-Force, Hotquads, Hetrick or Max RPM among others. We also use the Kasea/ETon output shaft because of the quickchange sprockets. We get the sprockets from Rebel Gears in TN. Good people and they manufacture the product they sell you.

Call Gary at g-forcepowersports.com for a good deal on the cases and transmission parts. He will probably send you DRR cases but they are interchangeable. We have used DRR, Apex, Kasea and Eton cases. The new Kasea cases require a good deal more prep so avoid those.


I couldn't find a great case split video but I found a few that should get you started at least. Feel free to PM me for any help you may need.


There are a couple of videos on YouTube


SR 50 (MINARELLI MA 50 LIQUID COOLED) ENGINE DISASSEMBLY WATER PUMP SIDE

(90's look just like 50's and 70's but the cases are smaller on th
50's and 70's) Also, There is not an oil pump on the waterpump side
on an apex. These units are shipped premix only. There are no starter
gears on the variator side because they ship kick only

Scooter How-To : Installing A Crankshaft In A 1E40QMB Engine

The case in the video is a long case with scooter trans but the crank
install is the same. I actually use crank tools from Tusk and I case split
with a tool I purchased at Harbor Freight.

Crankcase Sealing.AVI

(Use small craft paintbrushes instead of your finger)

He nailed it!! Once you dig in and start to split them it's easy from there. The hardest part is getting the shi-ty screw's out. I have a good set of cases i'll sale you for $75 shipped. But ya after removing the stator, the screw's are behind there, then remove the head and cylinder. After that you can then start to split the cases. All goes back just as easy with no major headaches... His lead's are also very good and should also offer good help and part's...

[wickestangwv]

PM sent on the cases and I appreciate the help guys.