Throttle/Brake servo linkage trim setting

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w13dle

Well-Known Member
Messages
61
Hi all Ive just replaced my Throttle/Brake servo with a Savox 1256, I put the servo horn on in its neutral position & it seems to be pushing slightly on the carb giving a higher idle so I'm having to use most my trim to bring it back, Im using a Hpi linkage adjusted to the SS manual, could somebody please advise me as to what I might be doing wrong? thanks
 
Not to re-question your statement: Are you sure it was in the neutral position, before you installed it. I had powered the servo on mine, before installation, and thought the same thing.

I replaced mine and ran into a similar issue, I figured if I adjust the horn to slightly negative of neutral it was perfect once the car was turned on. So if the servo is installed parallel with the car chassis, the servo horn would be slightly left (toward the rear), instead of perpendicular to the servo.
 
Remove the servo horn switch on the tx and rx now replace and center the servo horn, then use the trim to fine tune it to where it functions correctly
 
cheers for your advice guys, I've centred the trim on the controller removed the servo horn, switched on tx & rx then put then replaced thes horn at centred position, but I'm having to put the trim 30 one way to stop the whining on the servo,

http://s287.photobucket.com/albums/ll149/w13dle/?action=view&current=9ea4da56.mp4

Hi OuttaLuck, I think you tried to help me diagnose my spur gear trouble when I first got the Baja, nearly a year or so on you'll be happy to know I got to the bottom of it & its been running great, turned out replacing the engine with the SS CY 26cc & complete hpi gearbox solved the issue, I have a few treats in the cupboard as well a OBR 29.5 FM 990 carb:D

are you still running the Victory pipe? cheers
 
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w13dle said:
cheers for your advice guys, I've centred the trim on the controller removed the servo horn, switched on tx & rx then put then replaced thes horn at centred position, but I'm having to put the trim 30 one way to stop the whining on the servo,

http://s287.photobucket.com/albums/ll149/w13dle/?action=view&current=9ea4da56.mp4

Hi OuttaLuck, I think you tried to help me diagnose my spur gear trouble when I first got the Baja, nearly a year or so on you'll be happy to know I got to the bottom of it & its been running great, turned out replacing the engine with the SS CY 26cc & complete hpi gearbox solved the issue, I have a few treats in the cupboard as well a OBR 29.5 FM 990 carb:D

are you still running the Victory pipe? cheers
Click to expand...

Hi i remember helping you once before hows it all going good i hope?
yes im still running the vcr pipe on my obr 30.5 and loving it:D
 
I would'nt worry about the noise its just the servo communicating with the rx its normal for most good quality servo's to make that noise,

my hitech servo makes the same noise its all good
 
I'm good cheers mate:)

Im trying to dedice on a suited pipe, Im leaning towards the Victory Pro but also like the Fluid pipe which is cheaper & made closer to home.

couple of questions if I may what carb you running & oil?

The start of the video is with the trim at zero & the horn centred, it seems to be pushing on the throttle, I noticed as I pressed the brake slightly it slowed down the idle, with the trim tapered off at 30 max this is what I did towards the end of the video it reduced the idle & noise but brought the servo off centre abit over to the right, its reassuring knowing the noise isn't too bad as I don't want to be burning out many of these of at this price
 
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First of all the best pipe for your engine is the Victory Pro as it was designed for obr engines obr sent some of their engines to Victory rc and they came up with the vcr pro pipe..

i don't really know anything about fluid pipes

Im running a 990 walbro carb and i use Maxima 927 castor oil also used and recommended by the obr boys.. makes you engine run very clean with minimal carbon build up and it smells NICE :lol:

Im not to sure whats going on with you throttle servo maybe it has something to do with the voltage i think the savox servos are 7.4 volt system and your probably running a 6 volt battery pack im not sure.

You can also try resetting the horn after it creeps and see what it does...

what radio are you using?

Troy
 
You've just made up my mind, Victory Pro it is then, we have OBR boys over in the UK now but are waiting for new stock.

The Maxima oil is like rocking horse *!*! over here, I can find one seller which is very expensive & I don't know how reliable they'd be, I was curious as to what you was using, I've had a varied repose over here some say use Castrol a747, Silkolene K2, Klotz.

What do you use as you base settings for the 990, H,L, Idle?

I'm unsure because the original KM servo did the same but I didn't think anything of it until I replaced it, the radio gear is the Flysky gt3b, nice radio for a cheapy

Thanks
 
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The vrc pro pipe is worth the wait but beware of the unsilenced version as its loud but thats how i like em ;)

The flysky gt3b not abad budget radio i use to run the same one

Klotz is a good oil but i do prefer 927 castor oil i know its not cheap but its worth it partically with the amount of dollars we pay for these engines you want to give them the best fluids possible

Carb settings At the moment i have both H/L set 1 full turn out from fully in which gives me a rich mixture as im still breaking in mine but it may be different for you

Engine Break-in Procedure [/URL]

New engine break-in procedure
1. Take it easy on the engine for the first two tanks
2. Heat cycle twice, run the engine for 20 minutes and let it fully cool down
3. We recommend 91 octane fuel, mixed at 25:1 Our preffered oil is Castor 927
4. Let your engine warm up before driving
5. Try to vary the rpms during breaking.
5. DO NOT HOLD FULL THROTTLE UNTIL THE ENGINE IS COMPLETELY BROKEN IN!!!
7. Do not use octane booster

Troy
 
For your servo, take off the servo horn, with your radio, center the servo. Now before you replace the horn, loosen the throttle spring on the throttle rod. Now put the servo horn on and adjust the spring so it has a little tension, check the throttle arm on you carb and see how far it opens,if it's a little off fully closed, use the throttle EPA to ajust it,and slightly put a little more tension on the throttle rod spring, you should have it perfect now, adjusting epa so as the servo travels to fully opened and no more (epa), hope this helps you out.:)
 
I think I'll opt for the silenced VRC, me & my mate took the baja's out today he's running a rear Dom & my ears have been ringing all afternoon.

Cheers I'll use your carb settings as a rough guide & see how I go on.

I tried tuning my low speed needle on my current Km carb & couldn't hear no difference at all, I then tried tuning my mates L & the slightest move of the L I could hear the difference, so seems like this clone carb is duff.

cheers for the break in procedure.
 
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picked up a walbro 668 today fitted & to my surprise the servo sat ok in it centred position minimum noise but I couldn't seem to get the engine to start, after scratching my head for abit I noticed the throttle rod is slightly different angle on the 668 to the KM variant, with the KM carb & the servo centred its was on throttle slightly so I was having to back off on the trim, now on the 668 it wouldn't start with the servo centred so I have to use the opposite trim, thanks
 
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