F.A.Q.


Model: MX II Series

Question: I have an older MX II and want to update it to the MX IIA or MX IIHP. When was it produced and what is required?

The original model Quicksilver MX II, introduced in 1981, was later updated to the model MX IIA in about mid 1983. The MX IIA was last produced about 1985. There were a number of changes made to the airframe. To determine which model you have or to know what parts you need to upgrade the MXII to the MX IIA you should check the items listed below. You must upgrade the MX II to the MX IIA before you can upgrade it to the MX IIHP. Once you have done this or made the determination that you have the MX IIA, there is a complete kit available to upgrade the MX IIA to the MX IIHP. This is part #99410. The MX IIA used a 4 belt reduction drive system with a 52 inch propeller. The MX IIHP used a 5 belt reduction drive system with a 66 inch propeller. This gave you more power with less noise. The conversion kit includes all parts neccesary to make this conversion. The parts list is too numerous to list here. It does include drive system parts, propeller and airframe parts and tubes to make the MX IIA to MX IIHP conversion.

MX II and MX IIA Differences
The compression struts (except the one at the wing tip) on the MX IIA, should be double wall. That is a 1 inch diameter tube with a 1 1/8 inch oversleeve. The MX II had a single 1 inch diameter tube compression strut.

On the MX IIA there should be 4 compression struts per wing. 3 double walled compression struts per wing and one single walled compression strut (at the wing tip) per wing. The original MX II only had a total of 3 compression struts per wing.

On the MX IIA the diagonal strut in the wing, the one near the root tube, should be double walled. Again this a 1 inch tube with a 1 1/8 inch oversleeve. The MX II diagonal strut is single walled.

The lower wing flying wires should all be 1/8 inch for the MX II and the MX IIA. The upper wing flying wires on both models are 3/32 inch. If you upgrade from the MX II to the MX IIA you will need to replace all the lower wing wires, even if they are 1/8 inch, as they are a different length to accommodate the different style Tri-Bar Cross Tube. The upper wing wires are the same for both models.

The MX IIA has lower tail tubes. The MX II has lower tail wires.

On the MX IIA the lower front nose wire should be two separate wires to a three-hole tang (one hole for the bolt and two holes for the two wires). The MX II had a single lower nose wire looped and attached via a shackle to the two-hole tang (one hole for the bolt one for the wire attachment) on the root tube or it had two wires with two shackles attaching the wires to the three hole tang attached to the root tube. If you upgrade from the MX II to the MX IIA you will use the new part number for this wire #21600 which replaces the old lower nose wire part #20600.

On the MX IIA the upper nose wire should have what looks like a fork coming off the ends of the wire instead of a loop and tang. It looks somewhat like a turnbuckle fork. It is actually called a roll swage. The wire then bolts through this fork to the root tube and kingpost tangs. On the MX II the upper nose wire was looped and swaged onto the root tube and kingpost tangs.

On the MX IIA the Tri-Bar Cross Tube (the steel tube that goes under the seats and then points up off of each side of the seat) should be straight with the portion pointing up being a separate tube that is welded on. On the MX II the Tri-Bar Cross Tube is a single tube with about a 220 degree bend at each end pointing up. If you upgrade the MX II Tri-bar Cross Tube, part #80020 to the MX IIA Tri-Bar Cross Tube part #70555, you will also need to upgrade to the MX IIA Tri-Bar Down Tubes part #41230 as these are a different length than the MX II Tri-Bar Down Tubes.

On the MX IIA the horizontal stabilizer should have tapered metal frame all the way around its perimeter. On the MX II it is two straight tubes with fabric at the ends.

On the MX IIA the kingpost should be single wall steel. On the MX II it was most likely double walled aluminum.

On the MX IIA it had a teleflex guard kit which protects you from bending the rudder control cable should you drag your feet and they get pulled back under the seat which causes your leg to go back and bend the rudder control cable. The MX II did not have this protective guard kit and therefore you can see that the rudder Teleflex cable is exposed.

For the MX IIA and MX II the belt reduction system should be a 4 V-belt system. Some of the very early MX II's may have had a single cog (toothed) belt reduction drive system.

The MX IIA has wing ribs about every 18 inches. The MX II had wing ribs about every 36 inches.

On the MX II A the root tube bearing assembly at the back of the root tube that supports the root tube propeller shaft should be a machined and bolted together structure. On some very early MX II's it is possible some root tubes had a welded cup like structure that held the propeller shaft bearing.



Model: MX

Question: I have an '83 MX that I would like to put ailerons on. How much modification to the wing will I have to do?

There was no conversion kit for the changing the MX to ailerons. That is because so many things would have to change, it is probably not worth the investment. That being in comparison to selling what you have, taking the amount you would invest to convert and buying a Quicksilver model that came standard with ailerons. The items to change are as follows:

Aileron Kit (this was for the double surface MXL with spoilers).
New upper & lower wing wires to reduce the dihedral.
Rudder Pedal Conversion Kit.
Steerable Nose Wheel Kit.

The above, off the top of my head, would be in the range of about $2,000.00 give or take a little. There are probably a few odds and ends you need as well which escape me at the moment.

Then there is the issue of the wing itself. People who have done it on their own have cut down the wing span to 30 feet from it's current 32 feet. Otherwise you get a lot of flex in the wing past the last support wire. As this conversion was never approved by the engineering department, we cannot recommend you do any of the work for liability reasons. Or you could install the wing from the MX Sprint. But by the time you do all this, you might as well buy an MX Sprint.

So in a nutshell that is the low down on doing a conversion. For the two seat MX it was not so bad because you could retain the full size wing. For the MX however we cannot recommend anyway make modifications such as cutting and drilling their main wing spars.