Dear All, I am very new to RC Nitro cars/trucks and I would be grateful if you could help me solve my problem. I have purchased one GS Shadow ST1 RTR Truggy (Nitro). As per the manual or guide book break in procedure is the most important step to maintain and care for the car. In the manual it is mentioned,
Quote " Now check the throttle servo. Rotate the TH Trim button to the right (if u look inside the carburettor body, u will see the gap get bigger). This will rotate the throttle servo horn away from the engine, pulling the carburettor open. Now slowly rotate the knob towards the left and keep an eye on the shiny sleeve inside the carburettor. As soon as the sleeves stops moving, stop rotating the knob. This is ur throttle neutral point" unquote.
The problem I am facing is I cant seem to know where to look at to find the gap getting bigger or the movement of the shiny sleeve inside the carburettor for calibration. I am enclosing some pictures of the engine and would be grateful if anyone could show it by pointing out where to look for the shiny sleeve graphically.
Thanks for the assistance.

more pics of the engine

This is similar to the standard nitro engine throttle endpoint setup that they are referring to. 

See this video, you can see the carb opening and closing around 5:07.



Remember that your carb opening is covered up with the air-filter (the blue cylindrical thing next to the head of the engine), so you will have to remove that to see the carb opening.

You can see it again in this video.



At 1:30 he pulled out the air filter, and you can see the carb opening (closed and wide open) soon after (starting around 1:40).

Dear Mr. Anwar, As always thank you for opening clueless brains like mine all the time and thank you for being there, by the way what time do u go to sleep and what is ur occupation apart from being a webmaster.

My current line of work involves being in front of a laptop for a large part of the day, and a big chunk of what I do now is watching and responding to emails.  Since I have used the "Notify" option of the forum, I get emailed when new topics are posted.  The 2.5hour time difference between India and Qatar also makes it seem that I am responding at odd hours 

So u in the IT sector and where are uu actually from. Wow u really must be one hell of an RC veteran and enthusiast. So does ur hobby include all the RC equipments like boats, trains, cars, trucks, helis, planes etc. You must be having a big RC garage to keep all ur belongings there. Tell me if u dont mind the number of helis, cars,trucks,trains,planes do u own? 

Prem - You are missing a lot of the obvious ! User every post that I made, I have a link to my introduction, which includes my hangar.  I have also posted that I have been in RC for not very long and so on. Finally, individuals do not matter much, right ?

Quote from: anwar on December 28, 2009, 02:25:18 AM
Remember that your carb opening is covered up with the air-filter (the blue cylindrical thing next to the head of the engine), so you will have to remove that to see the carb opening.

Note that the air filter typically consists of a tube on top of which there is a foam filter, and the tube is sometimes attached to the carb opening with plastic tie-wraps.  So you may have to cut the tie wrap to remove the whole thing, and secure it with a fresh tie-wrap when you are done.

Dear Mr.Anwar, Thank  you again

Dear Mr.Anwar a very happy new year and let me be the first to start irritating you with my queries. As advised i took out the air filter and could see the sleeve inside the engine. But as luck or my bad luck always takes over i switched on my radio with new AA batteries and the receiver too with new batteries. the servo was in normal position and as it had been mentioned i rotated the TH trim all the way to the right but there was little movement only not much again as described in the vehicle manual i rotated the TH trim slowly to the left but the sleeve did not even move. i tried this process both is normal and reverse mode. Still as mentioned in the manual i pulled the throttle stick to max and roated the F.D/High knob to the left first and then to right to check for my max throtle range but there was no movement in the shiny sleeve. as no specific knob had been printed for F.D. knob i moved the small knob that was in between the ST trim and TH trim. am attaching the pic of the radio for ur information on whether the unnamed small knob is indeed the F.D knob or not as there are no more knobs. Kindly assist.

MORE PICS

Any suggestions guys, i have brought 12 new AA batteries and tried , but still no result.

Premvijay - if I may make a suggestion -

Its very difficult to for us discern what your problem is
sitting miles away as you are being
too long winded and overly descriptive.

Start from the beginning again -

What seems to be your problem ?

1. your throttle (acclerator) servo does not respond

2. your throttle trim is not responding .

3. your throttle servo is moving but the carburetor sleeve
    is not moving ?

- today is a slow day for me - so if you feel like it
   call me and I will try and talk you through -- 9435563873

all the best
 

Good to see local help offers between members.  That is how it should be ! SandeepM is another great example of this 

Prem -Since you are already familiar with how servos work, you can troubleshoot this using the basics.  All that happens is that a servo moves when you pull the throttle level, and that movement is transfered to the throttle arm on the carb.  With this basic premise, you can see where the issue is.  It *may* aid your troubleshooting if you remove the connecting rod from the servo arm, and see if the servo itself is moving enough/correctly.

Follow these step and it should work for you, but as most of them said, nothing compared to the help you could get from your local guys.
Step1:
Take the linkage off the carb and check the servo movement.
Go from full throttle to full barke. Servo should go equal both the ways and without binding.
Now check the trims. Does it move when you adjust the trims.
If no: servo may be bad or your radio.
Check if your steering trim work. If it also doesn't work, then something is wrong with your radio.
If steering trim works, switch the throttle servo and steering servo leads in the receiver. That means, your steering trim on the radio will control your throttle servo and vice versa. Check for both.
If everything works fine, continue to next step.

Step 2: Check your carb. Slide out the lsn arm (where the linkage from servo connect). It should be smooth as butter. If its not, take the carb out and wash it with some nitro fuel (no water) or kerosene (should be super clean) and blow air through all the inlets to clear out the dirt or anything that might be binding it. The carb should slide out smoothly and should go in perfectly. If thr is a little bit of crunching, you could damage the carb which might in turn cause air leaks and hence loss of tuning.

Step 3: Always make sure that the linkage from the servo horn to the carb should be absolutely straight with the carb angle. If its even 2-3 degree tilted, it will cause serious binding. Always try to connect the linkage nearest to the centre of the horn, as this will cause less travel, hence less angle change and hence less binding. You could also adjust the epa for it.

If you see in the pic, the linkage from servo is absolutely straight with the carb angle.

Your problem should be within this steps. Hope it get sorted out.

Dear All thanks for all the assistance, was out of station for the last two days so was unable to do anything. Immediately after posting this reply i will get on to the advises provided by u guys , once again thanks for showing so much, means a lot to us begineers 

Dear Mr.Anwar and Mr.Sandeep, thanks for all the assistance, i have managed to start the car and idle it too, so thanks again too rcindia..... but Dear Mr.Anwar dont think this is my last post  my next posts of radios and HPI trucks is to be posted right after i finish thanking you through this post. cheeeeeeerrrrrrrrsssssssssssssss.