Dear Friends,

It has been a few years that the RC bug bit me.
After flying electric helis for a while felt that time is ripe to expand my RC fleet  
I want to share with you an adventure I have embarked upon.

I have recently procured a Kyosho DBX - 1:10 scale nitro buggy from a friend and am now tasked with injecting life into it.
It is a RTR, was box packed, awaiting its first owner to unleash it.

Comes with a nitro engine (first for me ) - GXR 18 from Kyosho and a 2CH FM radio (another first , gonna be interesting after using 2.4 Ghz)

So far I have tested if the electrical system works fine, it does ! Steering, throttle action and breaks.

Now next up is firing up the engine and do the run in, I'm waiting for the fuel to arrive - 20% nitro
The engine's Japanese reliability will be tested if it starts up nicely considering the amount of time it has spent on the shelf  

I will share my progress with you all.
Will also share my plans to modify it - like the radio, LiPo/LiFe instead of the 4 Duracell AAs that go in the car, etc.

Here are a few pics after I unboxed it.

Cheers!

Hey, nice stuff.
Can you PM me your number- I'm into cars as well and would like to stay in touch

Regards

Make sure you go through some tutorials before firing it up. Nitros are fun but also requires some basics in order to run it for a longer period of time. Since it's a new car make sure you do the break in procedure properly. It would be better if you take some help from people who are already into it. Happy Firing.

Thank you Rishabh and Miginstruments for the messages !

In the meanwhile i tested the glow plug, works well, the filament glows bright orange when connected to the booster

Question
It uses a glow plug - KYO79405 : Kyosho G Glow plug
http://www.kyoshoamerica.com/74905-G-Glow-Plug_p_34.html

And it seems to be a "hot type"... refer this chart from OS's website, check the LC3
https://www.osengines.com/glowplugs/index.html

So which one i could use as a replacement when i need?
something locally available? will the dimensions and length of the threaded part be the same ??


Here are a few more pics.

-Canopy removed.... fuel tubing seems to be in good shape

-Steering servo and the tank.
Both servos are Kyosho branded. Came across some old forums on rctech.com where people have changed the steering servo to get good performance but i'll have to see how it drives first

-Receiver (FM, 2CH), on off button covering it and the throttle servo hidden behind

-The car turned over and the beautiful blue anodized chassis... probably the last time it is so beautiful. It is gonna be filled with scratches and bumps once it starts running  

In my next post ... something about the air filter foam.
It was destroyed by the long storage and importing a US$ 4 part from the US, paying US$ 20 shipping is out of question.
http://www.kyoshoamerica.com/Air-Cleaner-Sponge3pcs_p_814.html


Cheers !

Hi
Your pics show that you still have the air filter body, so only sponge element reqd.
Try cutting from 3M dishwashing scrubber. Looks like the right density.
If too dense compared to original, you can slice it thinner.
See if your manual says to oil the foam.
In any case, do not run the buggy without any filter.
Else dirt ingress will ruin the engine soon.

Dont know how much nitro in your fuel. Glow plug selection depends on that.
Hot fuel, cool plug. Cool fuel, hot plug.

Two things I remember from running these 30 years ago:
1. Need space. If run in small space, will hit boundary wall before you can stop  
2. Overheat and blow plug if restrained too long without airflow.

Enjoy. It'll be faster than you expect!
Regards

Hello, like Iyer Sir has explained Hot fuel, Cool plug & Cool fuel hot plug. Hence it also depends upon your location as well.  I personally use medium plug and they have proven me good results. They are available at aliexpress. go with OS plugs they are good ones, and also make sure that you dont buy just one plug, get 4-5 at once, coz no matter which plug you are using and under what conditions, they tend to blow, sometimes even while testing. Happy Racing.

Thanks Mr. Iyer and Miginstruments for the help with glow plug explaination.

I plan to run 20% Nitro fuel, so i guess 'hot' glow plug is better.
I only have a concern about the dimensions though. Are they all the same size and depth ?

To come around my air filter problem, i went ahead and bought a Baja XCD air filter for Rs. 58 (pictured) and cut a disk our of it. Oiled it with normal machine oil, removed excess oil and voila i have an air filter again  

Needles are adjusted-
1. High speed needle 3.5 turns from closed position
2. Low speed needle 2.5 turns from closed position
3. Idle needle - untouched

All set for the first start tomorrow.. gonna idle away the first tank and possibly the second one too while the car sits on a box, wheels lifted from the ground. Also gotta figure out if the radio has got any dual rate / expo on throttle and steering.
All that tomorrow.

Can't wait !

Here's some glow plug data
https://www.osengines.com/glowplugs/index.html

Btw, 20% nitro is quite hot. So you need a cool plug, not hot...

2 tanks in ! Totally exhausted as i had to be in the mechanic mode tuning the needles the whole day !

Here is what i discovered on day one

1. The battery compartment is a royal pain in the ..... you know where
Getting its lid closed with the battery tray + the wires + connectors is like trying to stuff into your old college time jeans, not much room in there.
I have to start searching for a LiFe pack
And the placement of this comopartment is right below the break arm assembly (really Kyosho  ?)
Quite a task to get those batteries in

2. Needle settings for run in mentioned in the manual dont work !
I spent the whole afternoon trying to start the engine only to realize i am running  too rich  - starter started feeling hard.
Some youtube videos later i ran the engine de-flooding procedure. This was repeated multiple times

Then adjusted the idle needle to give 1 mm gap, approx 1n3/4 turns of low speed needle, just over 2 turns of high speed needle and this did the trick

3. That sweet sound and smell of nitro 
Being a small engine, it is not too noisy, neighbours are thankful 

First tank lasted for 10 min, spent idling on a box
Second tank lasted a good 35 minutes somehow  half of the time spent idling and doing slow figure 8s for the rest of it.
I must be running it lean. It is a 100 ml tank

Here is vid i shot, sorry for the low light, the tuning fiasco led to me running it late in the evening



4. Range of the radio is limited ... 20 meters or so.
Advice welcome from FM tx experts

My next run will mostly be in the next weekend
Will keep you all posted

Cheers !

Squeeze the throttle already, lol

Update !!!

So tank numbers 3 , 4 and 5 happened in the meanwhile, the last one being this afternoon.

Here is some footage i got - of my first run in the daylight  



Tank 5 so i'm still running it in, needles as rich as possible.
It concludes the official running in period as per the manual but i plan to run it rich for at least a couple more tanks and then attempt tuning.

Also I might have found the solution to my radio range issue.
Guess i should just operate in open spaces with least possible obstructions and away from WiFi fields

Till next time, Cheers !

theres a failsafe set to cut throttle i hope?
also, take it to an open field, it needs big air!

I am running the same engine on a Kyosho mfr and the same fuel. My learnings about the GXR 18

- can be a little quirky, takes a looooot of time to build a nice stroke so run it rich for about 2-3 litres of nitro fuel before expecting super power (unlike whats in the manual). break in using 80-20 fuel if possible. Idle will be trouble some with 80-20 you will have to start it often. That 20% nitro will give you a great idle so use it only when doing the first circuit. before that break in using maybe 75-25 meth-castor... needs a lot of lubrication for the piston to seat well and yes heat cycling.
- almost impossible to tune correctly even after 4 tanks of run-in. Just when you'd imagine its all setup, it will fail to start and warrant a turn on the needles. Settles down only after burning 2-3 litres
- good you have a pull start, the electronic start is useless, it starts slipping very soon
- DIRT will kill your engine, so yes never without the air filter on. I just changed the piston liner and am breaking it in again now
- the idle setting on this engine needs a little tweaking so yea do not make the mistake of "high idle, low LSN"
- I personally find the heatsink needs to loose more heat, it does run super hot with 20%
- I've tried hot plugs and cold plugs on this.. OS No. 8 performs pretty well (but yes the secret sauce still is the highly lubricated break in)

Elsewise, this is a great engine for the vehicle once properly broken in
All the best

Regarding your radio range, what Radio is it? I got a perfex 72 MHz in the box and its pretty much crappy. there is no failsafe, so if the connection is lost, expect to run after the car like usain bolt (Ive done it twice and both times reminded me that I am getting older by the day). Also when I attach the glow booster, the servos twitch, indicating interference. I am planning to move to a 2.4Ghz myself.

Sometimes when I am low on energy for a sprint, I put it on my Frsky airplane radio. It works, just that I lose the fun of a Pistol grip.

Pickup a cheap flysky or some other 2.4g car radio with failsafe and lcd for easy setup, cheap rxs as well for flysky

Hi Rishab,

As Girish mentioned.... there is no fail safe on my radio either 

By the way have you used those FrSky surface radios? how was your experience with them? and range ?

_____________________________________________________________________________________________

Hi Girish,

The radio that came in the box is a Prefex 27Mhz. Yes a 27MHz, a generation older than even the 72Mhz.
I mean i recently saw in a toy store that all the cars (toy grade) are now offered with a basic 2.4 GHz Tx.

I too once had that moment when signal was lost and car went full throttle - only to be stopped by a parked car 
I also experience the same servo twitch issue that you mention + sometimes the servos chatter when i am indoors.

But last evening i took it to a big park and really there was no issue with the range.
I could easily take it ~40 meters away, solid signal which was enough.
I too feel like switching to 2.4GHz though, maybe later, if i could get a good deal on Futaba 3PV or Spektrum DX5c

As for the GXR 18,
I plan to keep using the same fuel and will not lean out so soon.

You mentioned that you changed the piston liner.... could you give any references from where you got these engine parts?
I might have to get some myself soon due to an incident on tank number 6 last evening
Also from where do you order parts for your car?

_____________________________________________________________________________________________

More on this "incident" in my next post after my full investigation.
I still did tank 7 after that 

Cheers !

I'm not sure if FrSky makes ground radios but yes if I had to I'd swear by FrSky resilience! I do have all plans of gutting out the Perfex RF circuitry and putting in a Frsky DIY kit... sometime soon. Will send you the details if you're interested in doing the same. I do get the chatter in open fields also, esp with the GP booster on, just that it is a little less noticeable and the eagerness to run the car takes over.

I had someone carry the piston liner set for me from UK. but yes I've ordered backplate and pull starter for the GXR-18 (ships to India) from here

https://www.ebay.com/sch/itembay4u
https://www.ebay.com/sch/pa39r

Hope that helps

I said flysky not Frsky lol

Quote from: rishabhbarma on April 16, 2018, 02:00:53 PM
I said flysky not Frsky lol

Oops!
Any experience to share about flysky?

Quote from: girishsarwal on April 16, 2018, 12:23:40 PM
putting in a Frsky DIY kit... sometime soon. Will send you the details if you're interested in doing the same.

Yes, please share when you do.
I found some videos on youtube but found them rather complicated

I'd prefer to stick to the Kyosho Perfex instead of the Flysky. The only reason that's make me changed my mind would be if I wanted to save the Kyosho Perfex (emotions of owning an original Kyosho radio) and perform the surgical procedure on the FS instead...

Quote from: Mightisright on April 16, 2018, 11:57:28 AM


More on this "incident" in my next post after my full investigation.
I still did tank 7 after that 

So my investigation is complete and the car is currently like the first picture here 
"The Exploded View" somewhat like they show in the manuals

Here is what happened: Tank 6-
1. Me and a friend were enjoying our rc machines in a dusty field on Sunday evening, him driving his Traxxas Rustler Stadium Truck - a 10th scale, 2 wheel drive electric powerhouse.
He had installed a wheelie bar to prevent flips and man, one should see the acceleration and the mad wheelies ! It was totally leaving my nitro buggy (and both of us quite literally) in the dust ! 

2. So on one such run somewhere in the dust we had a head on collision 
both of us were at half throttle

3. My engine sound became more strained and high pitched ... more revs... immediately but the car was running nevertheless

4. We examined both the cars (canopy not removed) and found things to be alright, we kept running.
I noticed that my buggy needed steering trim adjustment... it wanted to turn to the right while going straight
I trimmed it out and continued.

We had tuned my low and high speed needles to run even more rich before we started so we attributed the loss of top end to it being rich (still running in).

He drained his battery in another 10 minutes and i proceeded for a refill shortly after.

Then Tank 7 - i noticed that the car was lazy to take off. Also while my friend was driving my car, i noticed a discarded plastic bottle cap stuck in the front right steering / drive mechanism.

Stopped the car to check, found that the drive shaft was missing   
(shown by a red line in the picture, where it should have been)

That explained the steering... i was running a 3 wheel drive 

Later at home i decided to thoroughly check for damage.
When i tried to spin the engine flywheel, it felt jammed at the gear, like it feels when the meshing is too tight.
The engine could have moved due to impact and meshing with main gear would have got super tight.
Hence the strained engine, or so i thought at that point. As the drivetrain was not smooth it was trying hard to overcome whatever friction was there.

Upon further examination found the front drive shaft sporting a nice bend 
... the real culprit and cause of my engine revs/low speed problem

Checked other components - the clutch assembly main gear- transmission, front and rear transmissions, etc. , thankfully no more damage ...

Talked to my friend about what could have caused this. For now we could only identify that the impact did the damage. And also that his Rustler has zero damage !!
A testimony to the indestructible build quality of his Traxxas 

So I'm now waiting for the two drive shafts to arrive so that i can get things going again.

Will keep you all posted.

Cheers !

The dogbone is clearly bent, If it'd have been brittle it'd be in two pieces by now, so clearly you are using a quality product. it also depends on the collision, unfortunately you'd need to invest in a crash investigator to analyze

On a side note I hope there was an insurance company for rc cars (clearly, it'd be bankrupt by now) 

The Parts are here !   
As usual with some extras.

A big "  " to US postal services (USPS) and our very own India post for a speedy delivery. You guys almost matched speed with those big courier companies, Bravo !
The parts landed in my hands on the 10th day of ordering all the way from US west coast. Frankly I wasn't expecting such a fast service at 1/3rd the cost of a courier 

Gonna be re-building this weekend.

Cheers !

Quote from: Mightisright on April 18, 2018, 01:15:41 PM

Quote from: Mightisright on April 16, 2018, 11:57:28 AM


More on this "incident" in my next post after my full investigation.
I still did tank 7 after that  

A testimony to the indestructible build quality of his Traxxas  

So I'm now waiting for the two drive shafts to arrive so that i can get things going again.

Will keep you all posted.

Cheers !

Traxxas parts are cheap quality too. Gotta stock tonnes of spares. They probably make more in spare sales than in actual car sales lol.


And wow, was that delivery fast- my previous parcel via usps took 35 days--which service of theirs did you use? Or which website did you order from?

Congratulations, you should soon be back to grinding some rubber on the tracks.

I believe body pins and machine screws are easily available locally.

all the best! 

gs