ScottishRacer

Hi,

tried this in the rookie zone and got no response....

I just finished my first car, an Associated RC3 nitro... problem is it won't start. When I took the engine out and manually turned it, it got real difficult when the piston was at the top, then there was a sucking noise and all went smooth again. The starter box cannot cope with this. Any ideas??? It is a brand new STS 12 motor out of the box.

Thanks

IDrinkNitro

You might wanna try loosening the glow plug just a little. Or try heating the engine up with a heat gun, that usually helps with a tight motor.

ScottishRacer

I actually tried it without a glow plug, and it still didn't work. Any chance it is a defective engine

rod_b

Sounds like the engine is just tight...and that's ok. Heat the engine with a heatgun or hairdryer. It should turn over easy after that.

ScottishRacer

Thanks for the tips. Will give it a try tonight.

AMGRacer

My STS was a bear to get going initially, the piston liner fit is insanely tight. See if you can borrow a starterbox with one of those huge motors. If not make sure the piston is at the bottom of the liner before you bump it. It took much frustration on my part, but I got it there finally.

Turbo9000

iTrader: (5)

There should be plenty of pinch at TDC on a new engine. Even with the plug out you should feel it when the motor is cooled. The pinch will become weaker after the break-in procedure so starting should become easier. Using a heat gun or hairdryer may not be needed. I have broken in all of my motors with out that. Since you are also using a Starter box, I can tell you what works for me. I use the ofna box with a gel-cell and large motor rather than twin 550s, but this method should work on any box with a fresh charged battery. What usually happens is the flywheel will be able to spin a small amount and when it reaches TDC it will freeze up and not want to turn either way. The starter box motor doesn't have the torque to spin it any farther, the fly wheel will be stuck at TDC. Move the flywheel with your hand so that the piston is at the bottom of the stroke (where it begins to be easy to turn the flywheel) Let the starterbox motor spool up to its full RPMs and then quickly touch the flywheel to the starter box wheel. It should be traveling fast enough to get it over the TDC pinch and continue to spin until the motor starts.

Keith

R1ceboy

I had the same problem with my sirio. Had to borrow a friends starter box who had a stronger motor to start it the first few tanks. Also make sure that the starter box has a full charge, they tend to have more torque if so.

ScottishRacer

Thank's to everyone for their advice. I eventaully managed to get it started this evening by taking out the plug, washing the engine out with fuel and then heating it up with a hairdrier. Have 3 tanks through it now.

Now I just hope that I can set the engine so that it will run without me pulling the throttle. At present it always cuts out, so I can't even get the car onto the ground!!!

Thanks again everyone

R1ceboy

Try adjusting the idle stop screw so that you have a 1mm opening when the throttle is "fully closed"

au_Nightmare

My STS breakin was 2Ltrs of fuel before it was ready to start leaning out. So give it some time to break in, do not rush this. Follow the A4 sheet of instructions

I always pre-heat new engines, less stress on conrod etc then starting them when cold for the first few times.

Turbo9000

iTrader: (5)

Ask 10 different people and you'll get 10 different answers on breaking in... I dont know about the STS motors but 2 liters of fuel before leaning out sounds like waaaaaay too much. Perhaps you were running it in too rich, which puts even more stress on the conrod as it stretches. It is crucial to build the right amount of heat in the engine during break-in. Keeping it too cool only breaks the motor in for that cool temperature range. When the motor actually gets hot (racing temp.) The motor will re-seat. Now you have broken in the motor twice and will have a shorter life span if you plan on using it while at a racing temperature. As long as you run a overly rich setting nothing happens except the conrod wears out. When the engine is too rich there is so much oil going through the engine nothing can wear. If nothing wears how can the engine break in? You'll know when to start leaning when you remove the plug and feel if there is not a noticable parts bind or "pinch" at TDC anymore. I have never let the engine 4-stroke under load, only on the idleing 1st few tanks while flushing it out.

-This is just my .02
Keith

au_Nightmare

Other engines ive broken in (Force 21, Ho-Bao Hyper 8, Sirio .12 Trp Pro and Novarossi .12 cx) took no where near 2Ltrs, something more like 0.5 to 1Ltr. The STS Piston/Sleeve is one hard wearing tough cookie, with any luck that will translate in to a long life of high compression, just throw $15 conrods in

The STS Rep on these forums stresses to use 2Ltrs of fuel to break in the Dragons, try using 1Ltr and you may find the crank does not work too well in two parts.

(EDIT: and the "wanted sirio crank" is because my car hit a fence, car went under - engine didnt.. it was not a RPM/Tuning problem, more a spastic driving problem lol)

Turbo9000

iTrader: (5)

They must be doing somthing different...two liters is nuts. I use a fraction of that while breaking in my .15 and .21 novas.

au_Nightmare

Agree.. From what I have read the timing is a lot different to other engines also for low down punch.. (Maybe thats just the dragon series.. forget now..