Hi,
I am a very newbie to this, I had a Kyosho sandmaster st2 back in the days, 25 years ago. I just found it and thought I had it a go to start it.
The whole engine was very thick and oily and couldn't move, so I took it a part and washed it in clean alcohole, now it all turns fine. I have my old fuel where I mix it with nitrogen, I mixed the nitrogen apporximate 15%.
I bought a new glow plug K7 from Kyosho, I read on it that it required 1,5V. My glow starter is 1.2V. The glow plug doesn't turn "organge" by the heat but it does get warm and somes the left over fuel on it if I have it in my hand.

When I pull the motor to start it mostly does nothing, I have tried many times ( 50?) and two times the motor just started for maybe 0.5s and then died again. Can the problem be the old fuel? Or that the glow starter is 1.2V? Or do you have any other sugesstions? Can the plastic tubing from the tank to motor or exhaust to motor be dirty? They also had old fuel in them but they are fine blowing through them now? When my glow starter is in, there shouldnt be any issues with compression right? I will notice compression problems when removing the glow starter?

Thanks

/Tim

You're going to have to buy new fuel. Most of these things run 20% nitromethane and about 12% oil. The rest is alcohol. 25 year old fuel is maybe good for washing parts. Not for running your vehicle. I'd replace all the tubing, and make sure the fuel passages in the cab are clean. The needles have to be adjusted correctly for it to run. Rechargable batteries should make the glow plug glow bright orange. Make sure it's
fully charged. This is the manual for the truck. I took a quick look but didn't see the needle settings in there but I could have missed it. If you can find someone local that runs nitro they'd probably be glad to help you get it running. It's easy to mess up a motor by running it too lean.


https://usermanual.wiki/Document/kyo....122770469.pdf

Thanks, new fuel and tubes it is. Regarding the glow plug, my glow starter was fully charged at 1.35V and it didn't glow. Not much anyway, I'll try to charge it even more.
I have managed to find manual for car and motor so I know the needle supposed to be 3 turns open to begin with.

Is this a good fuel?

OPTIMIX READY-TO-RUN 16% FUEL 1L

OPTIMIX RTR 16 is supplied as a 1 liter container and is 16% (by weight) nitromethane with 15% fully synthetic oil from KLOTZ. This is a very high performance RTR fuel for general use not race applications. The tuning band on RTR fuels are wider and therefore a little less critical.

Content:

• 1L RTR fuel with 16% Nitromethane and 15% Klotz Synthetic oil

The 3 turns in the manual is the setting for a new engine. It's going to be pretty rich if your motor is already broken in. Too rich is better than too lean, though. The glow plug has to glow bright orange or the motor won't start. That's critical to starting it.
I prefer a mix of 50-50 synthetic and castor at 11-12 % oil. I always used 25 % nitro. That's just what I liked. The oil you picked would work as well. Any fuel is going to be better than 25 year old fuel. You might find an oil lugie in the carb passages too. an oil lugie is oil left in the passage and all the alcohol has evaporated. The oil dries out and you're left with a gob of semi dried oil. I've used carb cleaner to clean them out without having to take the carb apart but sometimes you have to take it apart. . Good luck. It would be a big help for you to have someone experienced with nitro cars there when you try to start it.

The fuel after a short time can congeal, (go thick) doesn't happen so much if its in a big container, but in the little small gaps in ur carburettor needles it goes thick and blocks the fuel getting through. If it were me, id make a note of the current needle settings, then carefully remove the needles, and clean out the holes with a solvent like brake clean or something similar. Give the needles a gentle rub with a clean cloth, Then refit and adjust the needles.

That opti fuel, I bought a gallon if that and ended up binning it, pure rubbish car would barely even start, when it did it wouldn't rev up. Other people tell me its fine etc but that was not my experience, i got proper fuel and car was running perfect again.

But yes if ur fuel is 25 years old u will doubtless need new stuff.

glowplug, I would imagine it should glow orange, certainly mine do, id imagine 1.2v or 1.5v should both be enough to light it. Perhaps if ur igniter is old though, that whilst it is charged up, its not providing enough current yo light the plug properly. Like when u charge up a flat car battery, it goes to 12v, and itll run a radio, but soon as u load it with turning over the engine it goes to 0v and wont work properly, could be the same story for ur glow igniter

Update:
New fuel, new tubing. The motor started right away, I could have it running for a long period, like 20sec. Then I removed the glow starter and it immediately started to run bad and just ran worse and worse until it stopped, this took maybe 1-2 seconds.

My guess is that this has something to do with the compression? I do miss the gasket between the motor and the cooling top (I wasnt allowed to post picture), and I could have possibly damaged to cylinder when I cleaned the motor. I have tried to find a replacement gasket but I can't seem to find it

EDIT: Ok I found the gasket, it was of metall so I didn't notice it

Glow plug is not hot enough...

How can it not be hot enough? It started the motor, and then the glow plug isn't used anymore right?

Change your glow plug. A glow plug doesn't stop working when you take off the igniter. It's working till the fuel stops going to the motor.

The glowplug will be lighten up with every combustions. With the heat some ions will come free that will make a chemical reaction with the fuel as a catalysator to speed up the combustion. If the wire of the plug is old, burned or coated with rust or carbon then the perfect working is gone. In other words if it is not shiny silver but more like grey, brown or black you need to replace it.
So it is wrong to say the glowplug is only needed to start the engine and it is also wrong to say that when it glows it must be fine. The working is much more than most think.

And as mentioned, these plugs come in several heat grades, be sure to use the right one or for sure not to far off of what is needed to use.

Ok, I understand.
The glow plug is brand new kyosho K7, for 10-25% nitro fuel. I bought a fuel that is 12% nitro. Will a kyosho K6 for 5-15% nitro work better?
/Tim

EDIT: I bought a K6, K5, and K4. The K7 was the coldest plug it seems

Looking at the original specs the car has a .12 airplane type engine (pretty normal in those days). I can not find a list of the K glow plugs but I think the 7 is rated too cold for such a small engine. With a low combustion power that this old engine generates it is difficult to heat up the plug to activate the next combustion and so it fades out and stops the engine. Beside that, the heat number of the plug also determines the ignition timing which will be far off...

I think you need to use a warm glow plug so I suggest to start with the 4.

I have really low understanding on how things work with the engine so bear with me.

I put the K4 in, no start.
Changing the K7 (which it had started with previously) no start.
Changing back and forth and sometimes it just fired up only to die again in no time.
Suddenly it started with the K7, but died when the glower removed.
Changed to K4, started but died with the glower removed.
Changed to K5, started and ran without glower, it doesn't run that smooth it is kind of up and down in noise
When I gave throttle it died

So K5 worked but died everytime I gave more throttle.

I also don't understand why it not started but then suddenly started at the same glow plug. When I finally after many tries got it to work, it worked everytime I pulled it. It was like it was perfect amount of fuel in the cylinder after I got it running and stayed that way. But when I try to start and also push in fuel from the fuel tank, I have problem to start it again.

What's your needle setting? Was the motor broken in when you ran it back in the day? If it was broken in back then and you have a new motor needle setting, it's too rich. Changing fuels you might want to do a mini breakin for a couple tanks. Either way the manual's 3 turns out is too rich for a broken in engine. Being too rich is hard on glow plugs, too. There's a learning curve to nitro. If you can find someone experienced with nitro cars it would help you immensely.

This. Also take your time with it, there’s no rush. Roughly how much did you run the engine for 25 years ago?