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Fair few problems can you help


Garry45

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Hi Guys

Please bear with me on this as a fair bit has happened to my car and will try to be as clear as noob can

1-problems started when I fuelled up set all factory settings on the carb,made sure trim on handset was right and the throttle idle was 0.5-1mm.

Fired it up and was running fast so adjusted the idle to a nice idle then out of the blue it screams it head off to full rpm,

I double checked everything again even carb settings,got the excess fuel from the engine and started it again,it idled for a few seconds and then went to full rpm screaming it's head off,I killed and again checked and checked the car.

Then I discovered the blue plastic spur gear (fitted to my eb4-s2.5)..was stripped and chunks out of the thread!!

How the hell did that happen??..any ideas would be welcome,

I only tried to start it and had only previously used my rc for a grand total of 10mins

I've ordered a new one and have stripped the car ready,not as hard as I thought but I no setting it properly takes a bit of time but I will do it..

MY MAIN CONCERN

Turning the engine over (with glow plug fitted) doesn't feel right now,it's hard to explain but it feels a bit stiffer on the pull cord and when it's gone from TDC there is usually a smooth transition to BDC but it feels stiff,

Also noticed that when I slowly pull on the cord the main flywheel does not turn as I've marked BDC to help aid cooling when/if I ever get to use the car...by my finger I can turn the engine over clockwise but it doesn't like it anticlockwise...

Also the thing that goes onto the flywheel that obviously drives the spur gear just spins freely like it's not attached to anything,is that supposed to be free like that??

I've got a bad feeling I've done some internal damage but I just can't work out how the hell the spur gear got munched and after a few seconds it revs it's nuts off!! ,

Any advice on this would be great guys

Garry

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try turning it over without the plug fitted, it will be easier to turn and you can feel for any stiffness alot easier if their is any, it will get stiffer towards tdc as the piston gets to the top of the bore

it wont like turning 'backwards' as the one way bearing is working to wind the pullcord tighter, it is winding the pullcord back in when you turn the flywheel (it will eventually stop turning as the pullcord wont wind any more)

 

EDIT

the bit that goes onto the flywheel, 'clutch bell' is supposed to spin free as when the engine revs the clutch shoes inside move out and cause it to start spinning/ moving, thats why the car doesnt move on idle and when you give it some thottle it will start to move off

Edited by fraggs
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try turning it over without the plug fitted, it will be easier to turn and you can feel for any stiffness alot easier if their is any, it will get stiffer towards tdc as the piston gets to the top of the bore

it wont like turning 'backwards' as the one way bearing is working to wind the pullcord tighter, it is winding the pullcord back in when you turn the flywheel (it will eventually stop turning as the pullcord wont wind any more)

 

EDIT

the bit that goes onto the flywheel, 'clutch bell' is supposed to spin free as when the engine revs the clutch shoes inside move out and cause it to start spinning/ moving, thats why the car doesnt move on idle and when you give it some thottle it will start to move off

Hi fraggs

Thanks for the post and just got off the blower with Motorsport uk and I just had that explained to me and your right if you turn the engine over anti clockwise it moves the start....

Took the glow plug out and all looks well with piston moving freely so that's a bloody relief

My other worry was why did it tick over for a few seconds and then scream it's head off????

That's the question I need answering as I'm not going to start it until I no more

Garry

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it could be a number of things, an air leak in any manner of places, around the tuning needle/screw ,on the engine back plate,carb,ect or it could be just down to settings.

First I would check for air leaks, now you have the engine out you might as well check it anyway to rule any leaks out

if you find a leak then great easy to fix and that was the problem if not then it is probs the tuning settings, best or easiest way to solve is to get along to a bash or meeting or a friend who knows how to tune nitro's failing that you can watch loads of guides on how to but first things first check it over for leaks, I think there is a guide how to do it at the top of the nitro section

hope you get it sorted mate, keep asking the questions if you get stuck

Stu

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Thanks for the reply,s guys and it's appreciated

I've just done a test on the 4 Duracell PlusPower batteries I had (still in the receiver) and there we'll down on power 1.45v each,

I don't no what the cut off voltage point on the transmitter/receiver is but I think "runaway train" could be it..

I'm usually a stickler for checking batteries but didn't think for a nano second it could be them there brand new and where checked!!

I'm hoping it was them as it's going to be easier replacing them than trying to find an air leak,

It explains why all was well for 4-5 seconds and running great then "full throttle" and I wouldn't have noticed if the fail safe had cut in as the car was against the wall.

Is this what happens when the receiver batteries fail (screams it's head off)???

If the car is a distance away surely it's going to damage the engine with full throttle stuck on?? .

If this is the case I think one of those bumble bee fuel safe gadgets is a must buy?? .

Garry

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Its when the car "runs away, hits something and still screams when you strip spur gears. When the reciever batteries run low it can do all sortds of weird things. Thats why it pays to fit a failsafe

Edited by Gashead
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hi you don`t need engine running to check just put batteries back in switch on transmitter and receiver and watch what happens to your throttle control after a short while. Fail safe should not give you full throttle but should be set up to brake, plus this only works for trans. failure not receiver battery failure. Keep the faith if unsure keep asking questions if unsure

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Thanks guys for the info

Ive got a built in fail safe and irs all set up and check its working before I run.

Am I correct that if the receiver battery's die like I think mine did it goes on full throttle???

So the fail safe on my rc only works for the transmitter and if the batteries drop below a certain voltage or loose signal the brakes come on.

I just didnt realise that if the receiver batteries fail its a run away train...

Defo going to look at a fuel line fail safe

Garry

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just do some simple tests: switch on tx, rx

switch off tx, -  the throttle should go to either brake or neutral. You could hold throttle at full and then switch off tx should still go to brake or neutral.If this doesn`t happen you need to set up your fail safe

with both on, hold throttle at full and switch off Rx and see what happens? this is what would happen if your batteries fail in Rx

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It shouldn't go to full throttle when the Rx batteries are low, the servo usually stays where it was was when the batteries fail, unless the fail safe kicks in.

And 1.45v per cell shouldn't engage the fail safe either as NiMh batteries have a nominal voltage of 1.2v and you can usually use 4 of them without issue.. 

Also if you had the car pinned up against a wall, then that's the reason you stripped the spur gear, as when the engine rev'd up and engaged the clutch something had to give if the car wasn't allowed to move.

In future if your breaking an engine in and want it to idle for the first tank, make sure the wheels are off the ground as the rev's will rise and fall.

 

As for the engine screaming at high rev's, it could be a number of things, did the servo open the throttle or throttle open some how? if not it's either an air leak or fuel starvation.

Edited by gavin28
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just do some simple tests: switch on tx, rx

switch off tx, - the throttle should go to either brake or neutral. You could hold throttle at full and then switch off tx should still go to brake or neutral.If this doesn`t happen you need to set up your fail safe

with both on, hold throttle at full and switch off Rx and see what happens? this is what would happen if your batteries fail in Rx

Thanks for the reply and will check the fail safe and I set it up as instructions but will defo have a closer look

Garry

Edited by Garry45
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Thanks Gavin

Wasn't sure on what sort of voltage drop the RX could handle till things go loco!!!!

That's at least one solution scrubbed off the list but gonna check fail safe and servos to make sure all is working as it should be.

Now I understand why the spur gear got chewed as it's never revved like that before and normally have it against the wall to warm up and fine tune the idle and pinch test (I'm learning on tuning but it's not sinking in).

From what you and others have said plus a bit of research on the web it is either like you say an air leak or fuel starvation.

Have got a kind member on here who is going to help me sort those problems out and get the car running how it should be.

Garry

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do you have a small spring on your carb? it should pull the carb back closed in the event of the receiver batterys failing (atleast i beleive thats what its for)

 

simply, with no power on if i pull my carb fully open it wont stay open, the spring always pulls it closed in the event theres no power(from electrics)

Edited by Nitro-Guy69
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do you have a small spring on your carb? it should pull the carb back closed in the event of the receiver batterys failing (atleast i beleive thats what its for)

 

simply, with no power on if i pull my carb fully open it wont stay open, the spring always pulls it closed in the event theres no power(from electrics)

your spot on and have just checked the spring and with all electrics off the throttle returns to the idle position.

Have also done the fail safe test and all is 100%

Garry

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