Jump to content
  • Join our community

    Sign-up for free and join our friendly community to chat and share all things R/C!

MTA4 S50 out after 3 years, Help would be much appreciated


Mr Rixter

Recommended Posts

Hello, I took my s50 out of a 3 year hibernation and after cleaning the engine the beast started with not much effort which surprised me a lot. However, after factory resetting the needles I took it out for some tuning and two main problems came up

 

1) The servos seem to be acting on their own when there is some range between the transmitter and the receiver.  I mean seriously moving on their own both the throttle and steering servo. This happens with the engine both on and off. If the transmitter is a couple of meters or closer to the truck then the servos don't move on their own but there is still some buzzing noise coming out of them. Any thoughts on this? Is it the receiver that needs replacing?

 

2)Sometimes I apply throttle, I can hear the engine revving  up but the truck does not move,  then all of a sudden it might start to move. Is this some kind of gearing problem?

 

Thank  you in advance, I would really like to get back into this hobby.

Edited by Mr Rixter
Link to comment
Share on other sites

Are you running a 2.4Ghz radio system?

What batteries are you running in the truck?

Is it the 3 speed box? as this is all controlled by the electrical system so might be related.

did you examine the clutch when you cleaned the engine?

This will help us get you going mate :)

Edited by sean-vrs
  • Like 3
Link to comment
Share on other sites

As above...a bit more info. will help.

 

When the engine is revving but car not moving- is the pinion/spur gear turning (the gears on the end of the engine) ?

Edited by Anthoop
Link to comment
Share on other sites

Thank  your for your replies. Its the original s50 so it uses a 27mhz radio system but I had no problems with it in the past. I'm using a 1500 6v hump pack. The electronics seem messed up to me.

 

I did not examine the  clutch but last time I used the truck it was running just  fine. So could it have broken during storage?

 

The gears at the end of the engine were moving but I will check again tomorrow morning just to be sure.  I also noticed the truck sometimes it would not switch to second gear.

Edited by Mr Rixter
Link to comment
Share on other sites

I took the truck out yesterday and made some interesting observations. The pinion/spur are spinning when the truck doesn't move but it only happens occasionally. I believe the receiver is at fault as all the servos go crazy on their own even if the transmitter is off. I want to replace the radio system with  a 2.4 ghz one http://www.modelsport.co.uk/carson-reflex-pro-2-lcd-3ch-2.4ghz-fhss-combo/rc-car-products/368278 I assume that receiver will work fine with the analog servos right? 

 

I also noticed I need to keep priming the truck every time I want to get it started after it cuts off and the fuel line contains many bubbles so there might be an air leak somewhere. The electronics need sorting before I can properly check other things as I cant control the truck atm. Could it be something else apart from the receiver? I tried some AA batteries and the same problem happens.

Edited by Mr Rixter
Link to comment
Share on other sites

That radio will work fine with your servos......you could track down the problem on your existing radio and fix it for less though....(and there are probably a whole host of different options to the radio set you linked).

 

You can of course test the radio without having the engine running....you can plug the battery straight into the receiver (to eliminate the switch)....you can wibble-wobble connections and antenna wire (to test for faulty connection)...generally I am thinking that if the radio system worked before then it still should...(not accounting for damp storage though).

If you do need to replace any part of the 27mhz system it will be cheap....

 

If the engine is stalling because it is running out of fuel then yes you have some fuel pressure/supply problem.

Link to comment
Share on other sites

I have an update as I took the truck out today. I upgraded the radio during the week to a 2.4ghz one which solved most of my problems as I can control the truck now and it never fails to move. It runs good on WOT with nice top speed and very good temperatures.

 

There is only one problem left. When I start the engine it idles fine and accelerates nicely. However, after a nice WOT sprint, I stop the car and when I try to accelerate again it bogs down and some times stalls, that happens only from 0-50% throttle. If it manages to get past the initial bog then it accelerates nicely into the second gear where it flies (forgot how fast this truck is). I immediately thought the LSN was  too rich (factory setting) but when I tried to lean it the stalling became really bad, could barely get the car moving without stalling so I reset it back to the factory setting where I kind of left it and called it a day. I'm using the TT R2 plug which is meant to run hot I think.

 

Any ideas on how to solve the initial bog? Checked the engine for leaks there was only some bubbles coming out from the back of the flywheel which I read is normal.

Link to comment
Share on other sites

Yeah it was too lean contrary to everything I've read. It shows that you should always just listen to your engine. Tuned it nicely today with the help of a thermometer and it now runs like a dream, had tons of fun bashing. Thanks for all the help.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...