Drat

I decieded to finally get an RC car. After going over mass information and local availibilty of parts, I went with the RC10GT Plus RTR. I am completely new to RC and completely expected to do something wrong. Anyway, here is what happend.

I purchased the car and when I got home I first checked the remote/reciever connection. All worked fine. I then checked all the bolts and tightened a few(Have not lock tighted anything yet).

Next I started charging the glow plug igniter, and put it up for the night. The next day, after 20 hours of charging I was ready to start the break in process.

I first checked all of the speed screws by screwing them in (not over tightening) and then unscrewing them to the ammount of turns suggested in the manual. I did not touch the idle screw because it looked ok.

So far so good, I think. Anyway... So next I lightly oil the filter and then I put some gas in the tank(Blue thunder 10%). After a fair ammount of pulls, it started up. I just let it sit there and do its thing, as I was just going to let the engine burn all of the fuel doing nothing as Tank 1 of the break in process. Well about 20-30 seconds into this idle, it starts to roll forward at a really slow rate. Thinking that this is normaly(and it could be) I just lifted up the back end so I didnt have the chase the thing. Next thing I know, the engine takes off. I have no idea if it was max or not, but throttle had not moved. So for a moment I thought this was normal. So I did the water test for heat, and it boiled off in less than a second so I climped the gas tube and the engine shut off.

I look over everything, and cant figure out why it took off. So I let it cool down, and gave it another go. It idles fine for a while, and then boom, it takes off again (wheels arnt spinning at all) and so i kill it right away. So i start looking around it again and I see my spur gear and 1/4 of it is torn/ripped/melted away.

All and all I went through not even a 1/4 of a tank of gas.

I am confused if I did anything wrong, or maybe because I am so new to these, I didnt check something listed on the check lists. I went over so many check lists so many times just so i didnt screw it up.

I plan on taking it to the local hobby store this week, for them to take a quick look at , and also get a new spur. But since I dont know what went wrong, I will most likely destory another.

Looking though these forums and others, I understand it could be break issues, clutch issues, and other issues. Any thoughts or comments you can give me would be great. Thanks for your time.



Drat

grampi

It sounds like the engine is going through a leaning out phase. Try opening the low speed mixture screw about 1/4 turn at a time. Wait until you replace the spur gear though. This is one reason I don't subscribe to idling the engine at all during the break-in period. If you have the mixture set too lean, the engine will overheat because of a lack of air flow. If the mixture is set correctly (which is rich for the break-in period), then the engine doesn't get hot enough. I recommend running the engine as rich as possible and driving the vehicle around varying the throttle to about half or so. Do this for the first couple of tanks, then vary the throttle up to full. This will keep the engine at about the right temps. After 4-5 tanks, you can start leaning it out for power.

Drat

Thank you for your response grampi.

Once I get the replacement spur gear, I will increase how rich the engine is running, and not let it sit.

I am still confused on why it ate the spur gear though, If i wasnt even trying to move. Just a result from a hot engine still breaking in?


--Drat

Forevafire1

yea i just got a NS4 and i let it sit to do its thing and it sounded like it was at full throttle(this is my second RC car) i just took it in to my hobby shop to let them fix it cuz i did not want to mess with the car (maybe when i have a little more confidence in myself) lol sry this might my a long post when i got my first RC car it was fine during break in so then i thought to race tune it and i blew out about 4 spur gears till my stupid mind finally thought to read the manual so it said to tighten the diff. and added some locktite to the engine mount screws and it made a world of difference

1fstxnt

drat first thing first, put loctite on all the screws that thread into metal. Loose screws can cause a world of trouble. Never allow the rear tires to spin with out a load! (on the ground) Next you want to check for air leaks, check the base of the carb, fuel lines, make sure the head is tight. Once you check all this set the needles back to the factory break in settings and try to start her up. The way grampi said to break it in is probley the best way to do it. As far as the spur gear check your gear mesh, also make sure the drive line all moves freely. Hope this helps, if you need any more help just ask. Where in ohio are you????

Drat

Turns out the factory mesh was to far, and thats why the spur stripped. And yes, it was running too lean but that isnt what cause the stripping, it was the mesh.


They replaced the spur and realigned the mesh. Also adjusted the lean some and the idle. Ran it for a few mins there and all seemed well.

They were cool about everything, and they didnt charge me for the spur or the labor. They said since you just got this, and this is "factory" set, you dont owe us anything. If it was anything else, most likely.

So now i get to restart the breaking process, er break-in process....

--Drat

1fstxnt

good luck man!!!! Are you near columbus??????????

Drat

Northwest Ohio Area. So an 1hr - 1.5hr from there.

1fstxnt

damn!!!!

grampi

Since we were discussing setting the gear mesh a bit, I thought I'd mention this. I actually posted a method to use for setting gear mesh about a week ago or so, which I saw in one of the magazines. However, I actually tried the procedure last night and it doesn't work. It has you insert a piece of notebook paper between the the two gears, then slide them together and tighten down the engine mount bolts. This method doesn't provide enough clearance. I've still found the best way to set the proper gear mesh is to slide the two together as close as possible and still have the gears turn smoothly when turning them by hand. You can easily tell if they're too tight because the gears will have a grinding feel to them when you turn them. If the proper amount of gap is achieved, you should be able to slide the tip of a needle just barely between the two gears. Proper gear mesh is critical to the lifespan of the spur gear, or both gears in the case where both are metal gears.

Drat

The guy at my LHS did the paper measure trick for mesh, but didnt like how the mesh looked, and ended up just setting and feeling the gears out.

--Drat

Drat

And.....


Another spur bites the dust
And another spur bites
and another spur bites
and another spur bites the dust


Oh yeah!

Well, I had a smile on my face for 4 mins while I did slow figure8s, then I stopped moving it for a moment, and "engine goes nuts time" and it chew it. Anyway...


Time for a beer.... or two... or three...

--Drat

hoodiegadoo

When breaking in the car don't pick it up off of the ground that takes the load off of the engine and will make the engine wind out....instead face the car into the wall or something to keep it from moving forward.....don't lift the rear wheels.

rc10_gt

Make sure ur drag brake is set right. and make sure it is running rich. I had the same problem when i took my car out and it was 1 deg. that day. it would idle good for a min or 4 then it would try to take off but i had the drag brake messed up so it wouldnt let my car move and it ate my spur gear.

1fstxnt

Did you try all the cures before you put the new spur on????? When you say the "engine goes nuts" what exactly does it do (redline and stay redlined, or flactuate) Does it just do it out of the blue? When it eats the spur does the car move(while eating it) If the engine just goes haywire every now and then you probley have some metal on metal rubbing going on. Try loctite on all metal to metal screws also check linkage for rubbing

Drat

The car was never off the ground in this last instance.


The break for some reason, has always bothered me. But being new Im not 100% sure how it should act in what instances.

I explained everything that happend to my LHS, and they put the spur on. I made suggestions of things people posted to look at. Before they put the 2nd spur on they looked at all types of things for like 30 mins or so.

"engine goes nuts" == acts like I am pressing the throttle, and I am not. Also the throttle isnt moving on the engine in this instance (aka, wierd interference). It just sits there, sounding good, and then all the suddend it powers up, faster and faster and faster, to a point, and then I kill it cause its going to over heat. I know it goes beyonds its temp range because a drop of water doesnt last a second.

Everytime It has eatten the spur, the car didnt move at all. Example: When all worked fine, from idle point, I would press the throttle a bit, engine would speed up to the point where it would move. When it eats the spur it sounds JUST like that, but it speeds up alot faster and doesnt move at all.

The metal on metal screws have been loctited also.

When they put the 2nd spur on, there was some issue where the spur would touch the back of the clutch bell. Meaning, when it was meshed with the clutch bell, the back of the bell , flat part, was touching the spur gear. But they adjusted a the engine around so that there was clearance. I hope that made some sense, as I dont know what else to call that part of the bell.

--Drat

hoodiegadoo

sounds like an air leak somewhere check all the gaskets and seals..