Optima questions

[mopar marv]

Good Day all,

I bought a rear motor Optima about four years ago. I picked it up from the original owner for $75.00. It was original right down to the mechanical speed controller. All it needed to run was a newer Tamiya battery connector.

The previous owner blew the drive chain and bought a new chain but never installed it.

He also bought a drive belt for it[still NIP] but I have been unable to find any info on what would all I would have to change to run the belt instead of the chain.

So I am looking for anyone that has performed this mod or has info on doing it.

The Optima also came with a Kyosho Lemans 360st motor but it has an issue that really puzzles me. If I pull the motor apart and clean it with 99% alcohol, it will run but as soon as I oil the bushings, all it will do is puff smoke when I connect it to a battery. If I spin the shaft when I put power to it, it will run no problem but if I disconnect the battery and then try again it smokes from the brush end. I have installed new brushes and made sure they are not hanging up in the brush hood.

Any ideas what the problem might be ? Or if I can get parts for this motor?


I am also looking for a copy or a scan of the manual for a Kyosho Lazer ZX-R


Any help with these issues would be greatly appreciated!

[Coelacanth]

I'll tackle your question on the belt conversion. It's not a simple drop-in upgrade unless you buy the Option House belt conversion as a full kit. It CAN be done without the kit but you'll need to do the following:

-Buy belt diffs for front and rear; these replace the diffs with sprockets for the chain with 'teeth' for a belt;

-Slightly modify your rear gearbox by cutting out a piece to allow installation of an idler gear--the purpose of which is to limit the belt rubbing along the upper chain guide;

-The belt conversion kit also includes a weird little Lexan piece that acts as a dust cover for the hole you cut in the gearbox;

-Install idler gear & route the belt inside the 2 halves of the rear gearbox before reassembling it along with the Lexan cover.

That's about it. If you can find the full kit, it's pretty pricy these days, you might pay $100, $150 or more for it.

[madmaxx]

Couldn't have said it better.... or you can get one of these but as stated above by Coelacanth they are pricy.

[tim.sanderson]

For the ZXr manual:
http://www.retromodelisme.com/scan_pages/1636/lazer-zx-r-kyosho-page-1.html
It's a bit of a pain in the butt to have to save each page as it's own image, but it's better than nothing.

[mopar marv]

Yikes,I knew it wasn't going to be an easy conversion but I wasn't expecting it would cost more than I paid for the Optima! The only reason I wanted to try the belt drive was to reduce drive line noise.

I guess I'll stick with the Chain Drive. Thanks for the info guys!

Due to the age and condition of my Optima, I don't plan on running it often anyway. That and I'm still not all that great a driver,I crash into everything including myself,lol. So the less I drive it, the safer the old buggy will be.

My Lazer is a much different deal though. I picked it up almost RTR but it is missing a lot of the original parts,like the body,under tray,servo mounts,2 rims,belt cover,body mounts,etc.... So I am converting it from an off-road buggy into a four wheel drive on-road car/truck[depending on the body I decide to run]. Again due to its age and rarity of spare parts, I won't be running it often. But I would really like to try a Traxxas VXL brush-less system on it, just for giggles. It was stupid fast with a 12 turn double on 7 cells but my old Novak 410c speedo puffed smoke and died. But I don't think the 410 was designed with 5000mah ni-mh battery packs in mind. Or a half hour of 40+ mph speed runs,lol. I must admit that I was really impressed with the way the Lazer handled at cruising speed. It is a lot of fun to drive!

tsan,
Thanks for the link! I've been looking for a manual for almost a year.

[tamiyadan]

.

[Coelacanth]

Stick with the chain drive.

I have the belt conversion from back in the day.

The belt drive is harder to maintain, and the idler pulley that gets installed in the rear gearbox with the lexan belt cover is a total PAIN to deal with when i comes to maintenance and durability.

The chain is more efficient then the belt anyway. The belt basically made the car less noisy, and the throttle response a little less choppy, if you run a ESC over the MSC the less choppy part pretty much goes away.

back in the 1980s The belt was considered the way to go for the future the chain was thought to be too heavy and clunky so everyone changed from chain drive to belt thinking it was an improvement.

I thought the move to the belt conversion was for a lot more than just noise reasons. The chain was always loosening and required maintenance, the car's 8 or 10 screws that needed to be loosened/tightened in order to adjust the chain tension was a constant PITA. The belt was supposed to eliminate all that annoyance. Of all the comments I've read about the move to the belt conversion, yours is the first I've encountered saying it was MORE maintenance than the chain. Swapping to the belt was supposed to make the Optima a lot less maintenance, not more...

[ROH73]

Mopar, based on how much you intend to run your Optima, I agree that chain drive is probably the way to go. The conversion is not worth the modern day prices for an occasional runner.

Chain drive is slightly more efficient than belt drive, but I completely disagree when it comes to maintenance. My original Turbo Optima (that I ran almost daily) required lots of maintenance to deal with a stretching chain, replacing worn chain guides, etc. I have not adjusted anything, even one time, since converting to belt drive in 1988. The idler pulley has worked just fine since then as well.

Now, for nostalgia's sake (and infrequent running), I like chain drive. In fact, I have a Javelin, a Rocky, a Turbo Rocky and a Yokomo YZ-834b that all use chain drive and I'll never change them over to belt. I'm also building another custom Optima that will use chain drive, but for "ease of use", IMO belt is the way to go.

[RichieRich]

When I raced my Optima, it required tons of maintenance when using the chain. It stretched a lot and I had to constantly adjust the length with all the screws. I think this is the reason you see worn out chassis rails where those screws go in. Eventually, I had to remove a link. I think the main reason for the belt was to keep maintenance at a lower level. I guess the success can be debated. Unfortunately, I had moved on to another car before the belt drive came out so I never got to use it under race conditions.

[GJW]

the chains always seem to stretch over time even with a slipper installed (eg rps yok) as apposed to a belt with kevlar, which i have read is stronger then steel. a chain drive optima is very cool just leave it that way and appreciate the evolution to the lazer show us ya beauty's

[mopar marv]

Thank you for the additional input guys,I really appreciate it!


GJW,
that's why I picked up my Lazer,I figured it would be a nice companion piece for my Optima. Old tech/newer tech. After I saw video of the Lazer running with the 12 t double and a lipo pack, I was hooked but good,lol.


What surprises me is how many people used to own and or race them[Optima and Lazer]. It kinda makes a guy wonder where they all ended up because they sure are hard to find now.
Unless you are willing to blow anywhere from $300.00 used to over a grand for a new in box unit. My wife would shoot me for even thinking of blowing that kinda dough on one RC,lol.

Coelacanth,I've got to ask,what is that cool beast pictured in your avatar?

[Coelacanth]

Coelacanth,I've got to ask,what is that cool beast pictured in your avatar?

That would be Project CYANide! A blue-anodized Turbo Optima fully converted and modded for on-road use.

I'd originally intended it to work as both on-road and offroad, but after going through major pains to do a proper on-road setup, I decided to leave it as-is and build another car (Barney) for strictly offroad use.

http://www.rc10talk.com/viewtopic.php?f=30&t=17726

[kaz_z]

the belt system does not fully eliminates the loosening problem, it will still skip if there's not enough tension, but it doesn't get loosen as easily as chain.

[mopar marv]

Wow,What can I say that a dozen people haven't said already?

That is amazing!!!!! And the body,you gotta know that a guy with my nickname would love that!

I plan on installing the same body on my on-road conversion LazerZX-r project.

Now I've got to ask, are you a fellow Mopar fan or just the liking the 'Cudas?

Way back, when my now 31 yr. old son was an infant,I used to race a killer '70 Cuda[12.24 sec.@124mph E.T.s]with an Edelbrock Tunnel Ram intake,two 500cfm Carter Competition series Carbs,504 lift Isky cam and Valve train,Balanced/Blueprinted .040 over 383,Borg and Beck 11.5" long style Clutch assembly,Slick shifted,Liberty built 4 speed with 5:21 gears and a locker in the rear end.
And I drove the car four and a half hours both ways to get to and from the track[S.I.R. just outside of Saskatoon,Sask.] And most folks say I'm lying but the Beast actually got between 17 and 20 mph.at 70mph. At 100mph I could downshift into third gear and punch it and smoke the tires so badly that everyone behind me had to stop because they couldn't see through the smoke.
I still get chills when ever I think about driving it. Without a doubt,it was the wickedest car I've ever owned!

[Coelacanth]

Thanks Marv! Yes, I'm a Mopar guy from way back...my first car was a $2200 rusty puke-green-colored 1970 Charger when I was about 19 or 20 years old. Externally now she's fine, but I have to replace the front floor pans & trunk and I'm gathering up some parts I need. I finally scored the taillight bezel trim last year, I think it took me 8 years to find one in great condition that didn't cost me hundreds of bucks. Now about 23 years later it's in need of a lot of work. I'm in the process of working on the interior but time & money (mostly money) is tight and not a lot of progress is being made.