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Percymon

Kyosho Optima Rebuild

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About time i posted another 'build' thread, so why not a vintage/classic Kyosho.

This is not a full restoration, and certainly not a recipe for lots of new parts keeping my postman busy. Hopefully at the end I'll have a respectable looking Optima that i can and will use lightly :D

So the starting point is a TC trade from back in April - it came with a repro bodyshell, plus decals. Obvious faults (known at time of the purchase) were semi worn tyres, a broken front bumper support and the usual cracked damper spring collars. So nothing major - hopefully nothing much else will materialise during strip down and inspection.

So the starting point (ignore the electrics and the new tyres, they just arrived the same day!).

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Pretty respectable, and certainly a lot better start than many of my previous projects !

I started to disassemble it back in May, but other projects took over and i parked it for 6 months. Its now fully stripped, but as a result of the prolonged breakdown i don't have any pics. Lets just say there wasn't really anything to report, a bit of dust n dirt but not much else.

So the start of the rebuild is the front and rear differentials - both are gear diffs.

This is the front diff prior to disassembly, inspection and cleaning - like I said nothing much more than surface dirt..

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Once opened up it was obvious there was no point in cleaning and relubing - the diff had seen little , if no, use since its last service..

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The grease appears to be something similar toTamiya Antiwear , so should give some nice resistance in the diff action. So back together it went. Bearings cleaned, tested (no issues) and relubed. Drive cups cleaned and refitted with blue threadloc on the grub screws..

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Next installment - rear diff..

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Nice! My Optima was in about the same condition when I got it, now mechanically restored and awaiting paint on a repro body (want to try box-art, but need to bone up on masking/painting skills first).

A little tip on the shock collars: the Raider/Pegasus friction shock collars are exactly the same, and you can sometimes find a whole Raider for less than some people are asking for "Optima" shock collars.

Also, if your final drive pinion is worn out (as they nearly all are), you can replace it with a Robinson Racing pinion gear for brushless motors. Part #8719. Just add a couple of old bushings to the shaft for spacers. Much cheaper than a "real" Optima hardened final pinion.

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Thanks Mark, much appreciated.

The final drive pinion is almost new, as you'll see tonights installment.

The Raider shock parts are useful to know.

I have found some pipe clamps that are anodized red alloy so I'm hoping they will do the job, although whether they are wide enough to retain the spring only time will tell

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I think you need to get the yellow shock's :D . As i may want the red one's :lol: .

Coming along nicely ..

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I bought a set of gold shocks for one of the Mid rebuilds, after the original set were ruined at the anodizers (screw threads corroded). I still have them and may well try to epoxy the caps and fill them from the bottom.

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Onto the rear then..

rear gear diff was exactly the same internally so back together it went, just cleaning off the surface dust n grease..

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This then gets installed into the rear gearcase and the chain added..

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Final drive pinon is then placed loosely in the casing..

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before adding the other half of the casing, the side plates, and bolting up...

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Yes at this stage that gear is floating aound in the casing, but fear not its captured by the drive gear and its long shaft..

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The top of the gearbox has a convenient port to allow the pinion to be accessed and secured in place on the flat of the through shaft..

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and then the cover cap is added, along with the rear shock tower - note how the tower is an interference fit with the side plates and hence only needs 2 x 12mm M3 self taping screws to secure it..

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At the other end the chain is placed over the correct 18T gear of the diff casing and it all wrapped by the front gear case..

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Looking good David, and I see your chain is the right way, not like when I rebuilt mine lol

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Looks great matey, I've never really paid much attention to non-Tamiyas but these Optimas do look interesting. Does the chain drive give them a unique sound or can you not really hear it?

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Looking good David, and I see your chain is the right way, not like when I rebuilt mine lol

I remembered your build Kym, hence I triple checked mine before taking the photos ! ;)

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Looks great matey, I've never really paid much attention to non-Tamiyas but these Optimas do look interesting. Does the chain drive give them a unique sound or can you not really hear it?

The chain is somewhat different yes, especially running in the front to rear channels which you'll see in the next few stages .

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Very different sound than shaft drive. Instead of the high-pitched Hotshot "whir," an Optima sort of hisses as the chain slides through its guides.

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Nice looking rig. I love the Optima series cars. I just realized that I restored my Turbo Optima 9 years ago!!! OMG.

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If it was 9 years ago, its probably due a service now :lol:;)

Managed a bit more tonight..

Next stage is to add some protection to the front gearbox. The original plastic U shaped bumper support was broken; pargu/pmg on eBay does an alloy which replicates the original but shortly after i bought this project i spotted a hot trick red alloy item in amongst a pile of parts on eBay. Thankfully the final price was OK and a load of extra Optima parts were scored for other projects at the same time.

So the hot trick support is added along with the skid plate that also further ties the gearcase together - the skid plate was distorted, but has been straightened enough to fit - it really needs a few hours of my time to reshape it back to original but its fine for now - function over form as they say :D

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Next stage is to add some plastic brackets for the upper chassis deck at the rear and to also secure in place the two square section rails that run the length of the chassis and gives it the wheelbase and rigidity..

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The front gearcase / skid plate is loosely attached at the other end..

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before side plates and more plastic brackets for the upper deck are added..

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The chain is then tensioned by sliding the front gearcasing forward in the slotted screw holes and tightening the screws.

The upper camber link bracket is added and screwed through into the gearcase to lock everything in place..

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The lower chain guide channel is then added, and its perspex top cover dropped in place..

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and secured at the rear with a small plate..

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Next step is to build the steering linkage and servo saver..

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and then drop into the chassis and secure from underneath, through the skid plate, with 15mm M3 machine screws..

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I start this next installment with an apology - having taken loads of photo's over the next few stages I wasn't unable to read the images from what was a new SD card. So in went an old one and i snapped a few images but they are end results rather than build ones.

So I left off last time with the bottom chain guide , so next was to install the hubs/uprights, arms and camber links.

Front hubs are alloy, axles supported by 1050 rubber sealed bearings inside and out. The C uprights are reinforced plastic, with a ball screw to mount the lower end of the shocks...

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These are attached to the front lower arms with a through hinge pin, secured with a e clip

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and at the inner end same hinge pin is anchored by a grub screw through the shoulder of the gear casing..

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Camber links are a bolt through ball on the inner end and a ball screw pivot on the outer end.

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The rear is a similar system, hubs are plastic with 1050 bearing inner and outer, camber links a bolt through ball at the outer and a ball stud at the inner end on the shock tower...

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Shock rebuild time, and this is where i lost a load of photos :(

The plastic preload clamps were split with age (typical) so another solution had to be found - these Phobya anodized pipe clamps from a refridgeration unit are the perfect colour, and the outer diameter is spot on for the spring diameter...

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The next step is fitting the upper chain guide and the top deck. Anyone who's seen an upper chain guide in the last 6-7 years is very priviledged, they'd been rare as hen's teeth for many years now and no repro parts exist that I know of. I was lucky to find a spare lower chain guide in the pile of Optima spares, and a trial fit looked promising. The front third of the chain guide was near enough the correct depth, but further back it was too deep resulting the upper deck plate sitting too high for its brackets. Surgery insued and after taking 3mm off the height of the chain guide along the rear 2/3rds of its length it was a good fit...

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Pretty happy with that - far better than playing with styrene / plasticard channels section and solvent glue

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I have a Turbo Optima I rebuilt about 6 months ago, following this thread with great interest. You post so many pics it feels as though Im building it!

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Aaarrrgghhhhhh! I hate this thread! I can see me buying an Optima resto project soon.

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This one has been rather neglected for the last 3 weeks, probably because i was at the electrics stage and i always lose impetus then :(

So today i sorted out the frayed battery wires on a Futaba MC310B ESC, and fitted male bullets to the motor wires (no MSC here :lol: )

The original three piece wheels are now disassembled, the inner and outer parts soaking in some bleach on the window sill to take ease away some of the yellowing from age. New tyres from Spain are already waiting.

Next stage the body :( :( :(

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Great work, brings back memories of rebuilding one a while back, never a car i loved, but thought, why not at the time lol....many £££ later haha, they do look great in box art livery though, classy

lee

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Nice work there.

I have a T/Optima waiting for a restore for the last 2 yrs.. I bought a new Optima shell from ***** & decals from [removed] as I don't like Marwans stickers as I have had them peel off too.

Got all the parts for the belt drive conversion over time so i need to get into it soon for a Boondall runner.

Can't wait to see the finished look of this build up :)

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I now have the wheels reassembled on new tyres.

Started to cut the body - its a poor example, wafer thin in some areas, thick in others. Right side in general thicker than the left. It also appears to be a little on the small side - align the front shocks with the cut out in the nose and the rear shocks are 5mm too far back - a little shuffling will have it sorted, but I'm thinking about trying another body such is the disappointment with this one. If I'd bought it myself I would be writing to the manufacturer, but as it came with the project i'll stick with it for the time being.

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It will fit, but the shock cut outs are off mate, had the same issue, it comes up short, looks killer still, more so with a boxart job, which is the big seller for me on the Optima, maybe the prettiest boxart ever!

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All cut now - like you say Lee its a little out at the front shock line but looks OK

will get some pics up tomorrow.

I'm leaning towards a dark silver and candy red scheme - the red to pick up the shock colours.

I don't think i have the patience for box-art on this one - not worth the hours for the quality of the lexan IMHO

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Well the original shell doesnt look like it has any damage, thats judging from your first pic. Couldnt you just remove the paint and repaint it boxart? Or is that body more beat up than it looks?

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