Nitroholic

If your fuel lines are full of fuel, and you block the exhaust outlet and spin over the engine, the overlap on the port timing will blow pressure back through the crankcase. It's only exit is the carb. Well...assuming your engine is properly sealed anyway. If your crankcase has a build up of fuel in it, say...from starting attempts or rich running, then fuel will spit back through the carb. the carbs on these things are very simple affairs. Just a slider or rotary valve really, to control the air flow. If your carb is at idle, there should be a small gap open for the air inlet, around 1mm or so at it's widest point. That means the air is going to come out under reasonable pressure. Enough to spit fuel. Take out the glowplug, turn the car upside down, and give it a few cranks with starter. Put a cloth down to catch whatever spits out. The previous owner may have had the car in storage with a big dollop of after run oil in there to prevent gumming or corrosion, or there could be a load of unburnt fuel in there. I'd give it a good clearout and see if it still does it.

I have been collecting up a set of parts to let me put together a new helicopter to round out my collection of small Eflite helis. I had an mCX, the s300mCX, the tandem twin mCX, but there was one last thing I needed to add to round out the set. I had one white body set, which I have used here as it seemed to fit better. Looks tidy enough, but it can look better.... when you turn the lights out 🙂 frame, landing skids, swashplate, tail and upper and lower blades all in 'glow in the dark' plastic.

A kilo reel of PLA is about £15 and it does a fair amount of printing.

Just bought a complete set of glow-in-the-dark parts for an mCX micro heli. Have plenty of spare parts to put together a flyer on this from my parts heap. I now need to do a quick assess of the fleet to check how well each is flying and attend to all the little issues. I think the white shell will go best with the glowy bits 🙂 Also bought and have now received a small vac forming kit. Plan to make some new shells for the little flyers. I can model and then 3D print the moulds and use that to vac form. It;s just an A4 size unit, as I never intended to be doing larger stuff. The PLA prints run at 220C, so the hot plastic shouldn;t be a problem. If it is...then I switch to 3D printing moulds to put plaster into.

I used to run around 1:33, and I always used a good premix oil. Sounds like you are going in the right direction in terms of tuning. The motor is revving out like it should, which is a good sign.

Postman brought me a small vac former. A4 sized base, which will be perfect for my plans to make shells for my micro RC helicopters, plus a number of other small projects I have planned. First, though, I need to 3D print the formers for what I want. Then I can make the shells.

not really now. A basic PLA filament printer can be had for around £200, which isn;t too bad. I have made a load of parts for hte RCs with mine, making battery boxes, servo mounts, etc. If I can model it in 3D software..then I can make it in plastic!

it crashed in a straight line... motor was a 4285 can, 1700Kv. Smooth can too, not finned. It was utterly unsuitable.

mine charges in around 15-20 minutes, but I usually only have a couple of batteries on charge at once. Try them one at a time, see how long. I am usually chargiong off mains too, not from a battery pack. If it's not a pack you know, then it's probably life expired.

Least I can confirm you ordered the right size when they finally arrive 🙂

Picked up an S300 mCX off EBay. It was only £29 and I mainly bought if for the good shell, tail and skid set on it. These are very hard to find for the S300 model, and I wanted a spare. Listing as usual tell you nothing about overall condition, but this one had a broken swash plate, a linkage that had been melted on after they snapped a ball joint off, and a servo that was stuck. Replaced the swash from my pile of parts ( I have a box full of assorted chassis, shells, blades etc. so everything I needed was there) cleaned up the servo and replaced the linkage. Gave it all a clean while it was apart to get rid of any fluff etc. plus I put a drop of oil on the bearings. While I was at it...I have started to adapt a damaged S300 canopy I had to fit on the mSR. It does go...sort of...but the rear mounts don't come close. I will be 3d printing some small pieces to hook it up. I have laso bought a small vac-former. The plan is to 3D print some moulds to vac form canopies. Shouldn;t be much effort to adapt the S300 shell and vac form some that will work better. As well as making some replacements for the stock part. Could have some fun.

I just had to buy some, as I wanted to rig up some 1S packs for my Tandem Twin. This uses a larger version of the batteryand are prety much unobtanium. I needed to find connectors: https://www.ebay.co.uk/itm/301942513575 JST 1.25 2 pin. I bought them so I could graft the right connector on a short tail. I have 3D printed a replica plastic cover that fits in the holder, so I can hot glue the pack in to the cover and plug in the wire.

what indeed .... I melted a diff housing once. But that was a result of putting way too big a motor in and ramping up the volts. I lost drive and found diff oil oozing out where it shouldn't! The bearings had got so hot they had literally melted the ends off the diff and warped the mounts too. That truck was very fast for a short period of time. As long as you don't mind replacing broken bits, sometimes you only find where the limit is by going beyond it.

So....you reckon taking all of the power and putting it through a single diff, rather than splkitting it between front and rear isn't going to put stress on that rear diff....

If you have a spark, and you have compression, it's probably a fuel issue. Take the plug out and leave it overnight so the crankcase dries out fully. Plug back in, prime and try to start. After a dozen or so pulls, plug out and check both plug condition and whether the combustion chamber smells of fuel. If it isn;t....then you got a carb issue. Do you know what carb your engine has? Also..what oil ratio are you using and what sort of 2-stroke oil are you mixing? What is your start routine? For a Baja, I always used the following: Choke on. Prime until the priming bulb is full and you feel resistance. Pull 3 times, the motor should 'cough' but not start. Choke off. Pull...and away she would go.

I used an old Turnigy bag for a while, but I think they have long since stopped making those. More recently, I used a Mil-Tec backpack. It;s a proper rucksack with loads of extra pockets and sections for stuff...but it;s main trick is it zips up, and the zip covers the top and down BOTH sides, so it opens completely. Very durable ( I have been using one on the biker to commute to work for over 10 years, and it's still solid. Not as waterproof as it used to be, but the straps are sound. It also is a Molle pack, so you have attachment points for carabiners, bungees etc. so if it won;t go in, ity can go on the outside instead! They do small packs, but the 36L one is probably right at 55cm x 29cm x 28cm. https://www.amazon.co.uk/Mil-Tec-Assault-Backpack-womens-unisex/dp/B01MCYZ7T7/ref=sr_1_16?dib=eyJ2IjoiMSJ9.GAU2fk4PAi4Oh9KM3FSGauoWtPV-K9GbwdQI7gZUYZhOksTuT9uhpPkh2Jv7S-FFPVBYk5C7S3-QQuzmTHTxu5-pYWLj_VbDzmJsYwj3a1DlqNY6Utwpn4T4V_mEOuIq3c1NTcX1TYMM4c-3uAIoa4pASA-39lvPNLtUjI50g6idX7chyAs2uw1AIIGJseGTa6rLsfokesGbizmgflNX7J_utFKgov6B7Y3JCRoL8I1gtZPQULd6ZI-cTyci8fNSJ7QTqS1zCQoZmpWSznWYW_NSNTSxtNCT9Huuor7izV0.cUZWPEn4TiZhaT16zeVRkqfm4EixcfEi2G0HiK1Svvw&dib_tag=se&qid=1711965775&refinements=p_4%3AMil-Tec&s=apparel&sr=1-16 come in various colours

Imgur for me too. works just fine

Those look similar to the motors on Heng Long tanks. I got some in the garage somewhere I can measure up if that helps

No. I wouldn't. The only reason for fitting a hard steel pinion is because a steel spur gear would tend to cause excessive wear on a brass one. Acetal won;t do that... but the harder pinion might cause issues with the spur, especially if your mesh is not 100%. It's also just not necessary. I try to avoid curing problems I don;t have when it comes to RC's, as you can often end up causing stress and issues elsewhere that you weren't expecting.

Welcome aboard 🙂 The Grasshopper is a fairly simple build, and a pretty old design, but I totally get the nostalgia. I keep getting the urge to build a Lunchbox, which is similarly dated, only I would have to try and rectify it's worst design flaws. can't help with a drift car, as the only Rc I have done any 'drifting' with was a Baja 5B, which on loose dirt was quite capable going sideways!

If you mesh it right....a steel spur isn't necessary unless you are getting issues with stones and grit getting under the shell andruibibng your spur. Had this bigtime on a mini Losi, which had a natural stone trap! Personally, a steel spur gear is a last resort....so I would start with the acetal one, and only go steel if I stripped it. Also important to make suire your pinion is right for your spur gear material. A steel spur eats a brass pinion.

Not sure exactly where it is you are putting this grease, but I have used lithium grease in many a gearbox on RCs. The only place I would not use it is where it will come into contact with grit or dust. The stuff gets trapped in the grease and turns it into a fine grinding paste. Inside a sealed diif, though, I would use decent quality silicon diff oil.

Depends what you are looking for. If you want a new Baja, get a KingMotor clone. They are the nearest thing to the real thing out there. Having owned both, the only issues I had with mine was down to prep work and the fact I bought the absolute cheapest one they did as I was going to swap a load of parts anyway. Sincew then, they have started putting better bits on and generally upped the spec a bit. I still wouldn;t buy an all alloyed one though, as they put things on that I simply would NOT have alloy. There were minor changes in gearing which meant gearboxes were not compatable, and they used to ship with some pretty awful servos. The gearbox worked fine ( once I replaced the diff oil and packed the housing with actual grease) and I replaced both servos with much better items. I think the newer KMs come with servos that are far more usable than the cheap toy ones I had back then. The shells were clear ABS though, rather than lexan. They do a 5T version, but you would have to be careful with the body. These guys: https://www.rcmodelz.co.uk/ are the importers for both the buggies and spares. The entry model KM001 now comes with a proper Walbro carb ( not the awful clone carb). alloy diff, reasonable shocks and a tuned pipe. Then you can just sit back, open the wallet, and upgrade from there..... They do a load of Rovan clones as well, but I have never tried one. They used to be rubbish. Might be a lot better...but I don't honestly know. I have only owned KM and genuine HPI.

Bit confused here.... if it wasn't sparking, the engine would not run. In your video...it's definitely running. If it has stopped running and won;t restart...take your plug out and give it a check. It's colour and condition will give an indication of what is going on. What 2 stroke oil are you mixing with the petrol? and to what ratio? That can also have an impact on the plug. Now.....drive from the motor uses a centrifugal clutch to drive the gears. It could be worn or damaged. Also worth checking to make sure all the gears are fully meshed, and that there are no loose grubscrews in the wheel squares at the back. Anything slipping will soak up the power as the diff sends power to the path of least resistance. It's working, or it wouldn;t move...but unless your motor is shot, it should move a bit more readily than it is.

And don't worry about soldering close to a LiPo battery. Unless you literally stick the soldering iron into the pack, it;s not an issue. The cells are joined with big soldered tabs when packs are asembled, and it's not a problem. I have soldered connectors to LiPos many times. Still on zero fires. Heat shrink is a must, as is making 100% sure you have the wires connected the right way round. Also, as Stormbringer mentioned, heatshrink is a good idea. You do not want exposed wires that could short the battery. That would kill the cell