Mini Mystic w/MHZ Drives Question

[danielplace1962]

Anyone used these drives on there 33" MiniMystic?

While building what I thought might be a problem turned out to be a real issue.
I mounted the drive itself on the sponson transom as low as it could go without grinding into the bottom but when mounting the rear pads the drive had too much negative and there is no way to get it out without recessing the rear pads through the bottom as the adjustment is collapsed all the way. Don't want to cut the holes in hull but it seems the only answer. You could maybe get the drive
1/16" lower on the transom but we need at least 3/16 just to get to neutral drive angles.

Anyone else have suggestions or have same problem?

Video running,

http://www.youtube.com/watch?v=NQoXfjGzpq0

Picture showing drive angle with too much negative.

[westbeach]

what is stopping you from mounting the drives flush to the bottom of the hull?? Did you dry fit the drives to give you neutral before you mounted the drives? Pics taken from the side and inside might help as well. Is this the suggested hardware for this particular hull??

[graill]

My dollar and two cents from just looking at the pic and the angle you took the picture. The rudder "seems" to large for that boat. both drives do not look like like they are at the same angle (you alluded to they are collapsed all the way, amy be the photo) . Yes there is alot of down angle on the drives in that fixed position.

Observations from the vid. the cg doesnt look right and or the motors sound like they are hitting an rpm wall, meaning they had nothing left to give with the rpm/prop combo which also adds to the porposing (front end bouncing up and down). Drive angles not being the same also add to the instability. (Again just looking at the pic you provided and the vid)

Possible solutions.
Mill the drive mounts and lose 1/16 as you have already thought of. reposition the drive mounts to the very bottom of the hull, gain 1/16. Make sure before any other adjustments your drives are exactly the same or your ride will suffer and adjustments will be that much harder to make. Your cg and your drive angle are intertwined so thats on you once you get your boat attitude correct.

Power? again it sounds as if the rpm wall is topped out and you dont have enough oomph to get the little beast on the last inch or two inches of pad, then it may just be my old ears.

Here is a free tip, when figuring your boats balance areas throw some masking tape, the tan stuff on it front/back/sides, and with your boat loaded and in the water use a perm marker and mark your starting areas, as you make adjustments you can make notes and record measurements. Once you find your sweet spot measure your taped areas centerlines and note them, the ones where the boat is stable, that way when you build your next rig if it is similar, you can look at your notes, set your boat up dry and be very close if not exact on that new setup, saves a ton of time and guess work and wear and tear on your equipment.

[Boatman]

Grail is da man. I have learned lots from him, like it or not:). Anyways, I had a similar situation with my CT04 and ended up having to remount the struts almost completely and grinding a good amount from the inside. Problem solved in my case.

As Grail also mentioned I tried "eyeballing" my struts and my first runs were terrible. I ended up taking the boat to Whirlpool model shop and putting it on a layout table and with a few different indicators had my strut angle's where they needed to be and the same as each other. HUGE difference in attitude of the hull and my small adjustments with props and c of g were more clear. Speaking of which I think I will go charge up and get a few runs this week while the FIPS are gone for the season!

[danielplace1962]

Thanks for all the replies. I appreciate it. I will see if I have other picts.

The drives are pretty much matched side to side the negative is the only issue. I made a setup table and used 24" long hardened rod to get the drives straight out the back and cenetered with same width at the drive as at ends of rods. Seems like the only resort I can do is recessing the rear stands into the hull. If I tried to get the drive itself lower it is still a good bit till it gets to neutral. Just worried the driveline line is going to be a bit shallow. Could these drives be the wrong ones for this hull alltogether and they make smaller ones? The MHZ prop hubs are half the diameter of drivedogs on these MHZ drives like they aren't matched possibly and smaller ones are available.

[westbeach]

It is possible that these are not the right drives for this size cat, as MHZ does have a 3 versions. And they obviously make drives for each different model. You should not have to do any modifications to make the drives work properly. Specially cutting the hull.

Could these drives be the wrong ones for this hull alltogether and they make smaller ones? The MHZ prop hubs are half the diameter of drivedogs on these MHZ drives like they aren't matched possibly and smaller ones are available.

[Boatman]

Westbeach is correct the hull should not need mods unless it's due to excess resin or such. If you could reverse mount the vertical supports meaning all you would see are the posts sticking down you may be ok. Just another thought

[danielplace1962]

Westbeach is correct the hull should not need mods unless it's due to excess resin or such. If you could reverse mount the vertical supports meaning all you would see are the posts sticking down you may be ok. Just another thought

Yes that might work it is just almost impossible to get up in there and do anything.

But yes if I put the whole stand inside and the nut plate on top I would gain a good bit. Great idea.

One wrench in the works, then how can you adjust them. Maybe if screws were facing forwrad you could get to it. ???

I am waiting to get a shaft and prop kit for the hull that might make some difference also. I see this kit contains set of all 3 blade props. They could make a difference for the better if they are more suited than the 2 blades I have now.

Here is the kit,