Newb asking; Engine troubles

[TTB1992]

Hi,

info:
A have an on-road car with a Force 15s engine. I is fitted with a pull start, a aluminium flywheel with a three shoe'd clutch and a two speed bell. My glowplug is a rossi r2 hot plug.
I run a methanol fuel (ofcourse) with 10% nitro.

Problem:
The car ran fine. I took it out, started it almost instantly, it ran a little on the rich side which I couldn't be bothered with since I wasn't going to race it. I was in a park, with people and children around, I don't like to let it get to far away from me then.

Roughly four tanks passed the engine head had been warm, but not hot, I could lift it by the head, hold it a couple of seconds before it became hottish to my fingers.

But then the engine stalled.
My first thought was of an empty tank, but to my great surprise, the tank was half full. The darn thing did not want to start any more...
I checked the fuel flow to the engine, but nothing strange here. I took of the air filter, checked the carb, but noting was out of order. I checked the exhaust pressure line, but nothing was clogged.

I walked it home, tried again, and felt that it turned over quite heavily. Glow plug out, excess fuel out, carb a litle leaner, try again. nothing. I runs super smooth with the glow plug out, but once it is in, I fear of breaking my pullstart. If I pull it anyways it sounds like it 'explodes' but doesn't have the power to continue the cycle. It starts smelling of burnt fuel after pulling the string a couple of times.

Summary:
Engine wont start.
Tried:
-charging plug glower thing
-changing plug
-checked the fuel lines
-checked the carb
-checked the fuel tank
-checked the exhaust system (manifold and all)

What do I miss here?

Tim

 

[Rolex]

Running rich and only "warm" is fine for a new engine during break in but is very hard on it after that. Heat is normal and required for these engines. Some of them like to run at about 285 degrees.
Remove the glow plug and plug it into the igniter. How bright is it?
What is the temperature outside where you are running it?
Did the cold plug come with the engine or did you change to it?
Why are you running 10% and not 20?

 

[TTB1992]

Remove the glow plug and plug it into the igniter. How bright is it? Bright orange
What is the temperature outside where you are running it? when it worked and stalled, roughly 15deg celcius, +-60deg farenheit. As we speak it is roughly 32 degrees farenheit outside.
Did the cold plug come with the engine or did you change to it? It's not a cold plug, it's a hot plug. I got it from the guy at the shop, he said it was a replacement for the stock one.
Why are you running 10% and not 20? Because it was advised. I do not have a clue otherwise. why shouldn't I?

 

[TTB1992]

Well, guess what.

I took out the plug again and pulled the pullstart. To my great surprise a little liquid came out. Not like a spray. More like this little droplet I saw flying accidentaly. I decided to flip the car and pull like an idiot. Slow liquid came out. I presume oil.

After some more pulling I reinstalled the glow plug. Funnily enough the engine could now be turned over by hand.
I Filled my tank and went to start the vehicle.

After three pulls and promising grunts, my pull start broke. Fudge.

Dismounted the engine, took off the exhaust in the process.
Breaking some rules of wisdom i mounted my electric drill to the engine. Plugged in my glow starter and turned the engine over. With more noise than I expected puffs of smoke were launched from the manifold.

I am now on my way to buy a new pullstart. But the engine turns over by hand. Which is a massive improvement.

Rolex, please still answer your questions. I am really curious.

Tim

 

[olds97_lss]

20% nitro is usually the minimum a lot of us run. It's a good mix of price/performance and ease of use.

From what you wrote, it does sound like your running on the rich side. @60F ambient, you should be able to run with head temps between 210F-240F without issue. That's too hot to hold onto with your hand.

I'd find a cheap temp gauge to help you get things dialed in better. I've been bashing for 15+ years and I still use a temp gauge every time I run just to make sure I'm safe.

 

[Rolex]

Olds has it all covered in the post above me.
Finding that much oil in the cylinder pretty much answered all your questions. It was too rich, flooded, wouldn't start, filled up with oil from trying to start, wouldn't turn over any more, broke the pull start.
Between helis, planes, boats, cars, trucks and bikes, I've been running nitro engines for many years and I've never seen 10%.

 

[TTB1992]

Well okay then.
I still got a liter, (which converts to roughly a quarter gallon) of 10 percent. afterwards I will switch to 16 percent. (the store sells 10 and 16)

Problem is still here though. New pull start, new hope.
no use.

The engine turns over smooth-ish, gnarls as if it is about to start. exhales smoke, but never really catches on.

I quote from the manual

Factory setting of carburetor: With the following basic adjustment the engine starts immediately, running perfect and rich enough (outside temperature 8°C).
• Idle stop screw: approx. 1 mm air gap;
• High speed needle valve: screw in completely, then open 4 full turns;
• Low speed needle valve (linking): flush with the edge of the linking arm, then 1 full turn clockwise;

After run-in is finished the high speed needle valve should be open at least 3 and 1⁄4 turns. A richer setup is better if outside temperature is high.

Well. nothing.

I got one of those infrared thermometer devices. the engine block was 15deg celcius (59 deg farenheit) during my try to start it.

 

[Rolex]

How old is your fuel? If I were you, I'd buy a new container of 15% and get it running. After all is good, you can try the 10% and see if it still runs on it.

 

[olds97_lss]

Where are you located? I've read some posts outside the US and they use lower percentage a lot as that's all they can get without mixing their own fuel.

Also, broken pull-starts can usually be fixed. The ropes usually break near the end of the pull or at the handle, which means you have a shorter rope after cutting, threading and tieing a new knot. Springs usually break near the ends, which can be fixed by applying a little heat to the new end to remove tempor, then shaping it to fit properly and rewinding it.

Might be a bit above your skill level at the moment, but might be worth fussing with while you wait. Don't have much to lose. If you have to recoil the spring, wipe it clean with a paper towel wetted with DA (denatured alcohol) first to make it easier to hold onto and, if it gets loose and cuts you, less grit/grime in your cuts. Once it's rewound and back in the case, put a drop or two of light oil on it to lube it.

You can find vids on how to rebuild a recoil:

That guy does it a bit different than me, end result is the same.

 

[TTB1992]

@Rolex, I will get new fuel as soon as I can. Although It's only a couple of weeks old and is kept in a metal can with a twist cap. Sooner or later it would be time to switch anyways.

@olds97_lss I am from the Netherlands. The shop mixes the fuels itself. Technically he could mix anything he wants.

Thanks a lot for the spring fixing tip. I might make some time for this. I am a bicycle mechanic by trade, so I know my way about finnicky springy things.

 

[Rolex]

All good info. Keep us posted, we'll be here when you need us.

 

[olds97_lss]

[USER=1493]@olds97_lss I am from the Netherlands. The shop mixes the fuels itself. Technically he could mix anything he wants.[/USER]

Nitro is probably the expensive per oz part of the fuel, so would make sense they would make a lower rated fuel to keep the price down. None of the stores (all 2 of them) that I buy fuel at mix their own. They just sell a myriad of brands and nitro/oil contents. I now run 25% nitro because my LRP28's seem to run way better on it than 20%. To avoid having to keep multiple fuels, I just run the same stuff in all my rigs and they all seem to do well.

9 out of 10 times, I have to buy a gallon of 20% nitro and a gallon of 30% nitro, then I mix them 50/50 in spare bottles to end up with closer to 25% nitro. Is a pain, but if I'm not breaking in engines, a gallon or two will easily last me through the season. I just try to avoid buying too much so it doesn't go stale by the next season.

 

[TTB1992]

Well then, I recieved the fuel in the mail today,

It's 16%.

Poured it in, primed the engine. pulled the cord over and over, took a multimeter to my starter, read 1.3v. but nothing!

again, a grunt, an ignition, another one, a couple in series, but no fudging running engine.

what else is there to check?

 

[olds97_lss]

If you take the glowplug out, put it in the heater, does it glow a bright orange/yellow?

What are your ambient temps your starting it in? If it's below 50F, you may need to heat the engine up to get it to fire. Nitro engines are pretty particular about being started when it's colder out. I don't even bother trying to start mine without heating them first if it's below 65F outside.

 

[TTB1992]

Yes, it's bright orange. This is the first thing I checked, and keep checking.

I tried starting it in the kitchen, where it is at least 60F.

 

[TTB1992]

I brought in tot the shop today, normally I am all in when it comes to diy and learning new things.

But this time I have to admit my defeat.

We will see what returns.
Thanks a great bunch so far.

 

[TTB1992]

You guys will never guess. I got my car back.
I only had to ask nicely every 3 weeks...
Guess where I am never going again!

Anyhow, the guy at the shop told me the flywheel was loose, the clutch shoes mounted incorrectly and the engine was tuned incorrectly.

I can believe the last bit, I've been fumbling with it a lot, but the first two were thing he did...

Right now, the car starts at the second pull, I can live with that

Anyway, Thanks you guys for the input!

 

[Rolex]

I'm glad you've got it running now, but it should have taken the guy about an hour.