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Hey guys,
New here, I recently got this kit from my friend father’s
He build it in the 80’ never run it
I want to restore it to driving condition
(I come from the rc crawler world don’t know much about this buggy)
First I disassembled everything (I must say the build quality is amazing)
I have original Kyosho stock 05 motor in the box (should I change it to something newer?)
I’m planning to use hobbywing 1060 or istd 70 that I have
The shock collars are half cracked half broken I did found some replacement for it (scorpion re should be as same dimensions)
I have problem with the servo
The original servo had this over complicated mechanizem
How can I run my servo without this wired horn?
Sorry for my bad English and thanks in advance!

Hey there, what a great find! I don’t recall the Optima “Pro” model from back in the day, they made so many kits back then. I had a couple Kyosho cars in the 80s, and I recall the nice quality of the parts.

I would start out with the kit motor, it should work fine. If you have only done crawling this buggy will be much faster and it will take a little practice to adjust to the speed. You can always put in a modern faster motor later. I don’t think these old 05 base motors are particularly collectible.

You may be able to replace the steering hardware with a modern threaded rod and ball cups, and put a ball stud right on the servo horn and ditch the adapter. But honestly I can’t quite figure out how that set up works from the diagram, it looks like the wire sits above the servo spline, while the horn points down, it looks odd. You might want to post some photos of it all assembled in order to solicit some ideas of how to change it,

It seems to me the Optima Pro steering basics are similar to the original Optima/Turbo Optima, other than having that weird adapter--and a longer wire link to account for the longer wheelbase. I haven't built a Pro so I'm not familiar with it, but I'm pretty sure it had a longer wheelbase. The Optima predecessors had a simple down-pointing servo arm and a wire link going to the Ackerman steering linkage. It wasn't optimal. I did this mod with most of my Optima builds, perhaps this might give you some ideas. As sondeen said, simply replace it with another servo horn; aluminum ones are nice, and a turnbuckle instead of a wire link, which you can easily adjust without popping ball ends or cups off the linkage.

I got better steering having the servo horn pointing upward, but you'll need to watch clearances with your screws and use open ball-ends instead of ball cups to avoid anything binding. I might have had to file the hole a bit longer in the FRP top plate too, if I remember correctly, to permit full servo throw of the aluminum horn.

The servo horn mechanism keeps the rod from arcing downwards since it has a long path over the battery and to the servo crank. You could rework it to use a standard horn pointed upward and rebend the linkage as needed.

The pro wheelbase is unchanged, it was essentially a optima (standard not turbo) with a different upper chassis and body. The battery is pushed forward with this upper so the servo would be in the way if mounted like the regular optimas.

Here is the conversion I sell for the 2016 to make it more like a pro, as you can see the battery is shifted ahead 8mm

Thanks guys!
Unfortunately I won’t have time this week to keep the build
If I understand correctly I can put new servo with the horn up instead of this over complicated mechanism?

You can, it will just be harder to make it fit well and clear everything. If you have the stock system I would run it.

The stock servo is bad
The horn is a little cracked but I can fix it
The problem is that I have 25 t servo
The og one seems smaller diameter

The servo horn is user supplied, so you can use a standard futaba horn on there

Found shock collar replacement (from 2014 scorpion)
Wich oil should I put in them?
I have 40w from my crawler but it seems to thick

Those shock collars are TERRIBLE. Practically every one cracks right at the screw holes. Those are also very finicky with the amount of shock oil to pour in before installing the shock ends; a few drops too much and the pistons won't compress; too little and they're too weak and spongy. I'd say 30W or 35W would be in the ballpark.

GoMachV wrote: ↑Tue Sep 05, 2023 7:22 pm The servo horn mechanism keeps the rod from arcing downwards since it has a long path over the battery and to the servo crank. You could rework it to use a standard horn pointed upward and rebend the linkage as needed.

The pro wheelbase is unchanged, it was essentially a optima (standard not turbo) with a different upper chassis and body. The battery is pushed forward with this upper so the servo would be in the way if mounted like the regular optimas.

Here is the conversion I sell for the 2016 to make it more like a pro, as you can see the battery is shifted ahead 8mm

Where is this on your site? I don't find it.

we ran out of the clodbuster linkage rods that we were using and pulled the listing a while back, but apart from that linkage we can still offer them as a special request. Best to message us here or through the website for info

Managed to find similar servo horn
After a lot of trimming (in order to connect it to the opposite side) it’s look good
Need to trim the length of the horn (if needed I will discover in the future)

So today I’ve finished the build part
Everything works fine (test in house low speed)
Currently running the stock Kyosho motor
Isdt 70 esc, 25 kg servo
Still Ned to tie and arrange all the electronic nice
And paint the body
What’s your opinion in the antenna rod? I like it because it’s giving retro vibe

Painted the shell today
First time I’m ever painting lexan shell or any shell at all