PSG-1

I've got a mach .26 and i've ALWAYS had problems starting it, ever since I got it. It always starts then dies.... starts then dies... almost immediately afterwards. I tried setting everything back to factory as i figured it'd start and run, just be really rich... still same thing. It hydrolocks almost every time after that too and then I have to take the glow plug out and pull the engine through a few times to get fuel out and then put the glow plug back and just hope it starts. I have to start it and be on the gas almost right afterwards and start going. Another thing is i just went through 2 glow plugs in about 3 tanks... which i would think means it's running rich but the settings i have right now are really really lean as that's the only way it'll run.... just starts really really bad. Any help?

tmodlin

Is the idle screw set open enough?

Nitronutt

My Feedback: (2)

I always recommend beginning any engine troubleshooting with 1) a fully (& freshly) charged ignitor, 2) a close inspection and 3) a good sealing: http://www.wildhobbies.com/news/defa...articleid=1233

When you go through glow plugs, what are the symptoms? Is the wire wet & simply won't light enough to fire? If that is the case, clean the plug coil with brake parts or carb cleaner, dry and reinstall. If the wire is broken (In a few tanks or less) or shoved up in the hole, then you are running too lean.

You said that you have to open the throttle to start it, this is common when warm as most big blocks require a bit more fuel to fire. You should not have to do this cold. Try the above sealing before anything else.

With the mach, I highly recommend the McCoy MC9 plug, Properly tuned, the MC9 can last for a gallon+!

PSG-1

I'm also having really really big problems with my carb not closing all the way... i've got the ofna throttle linkage on there but i'm still having really big problems. I noticed that it seems that the little notch in the carb slider where the idle needle fits into is grooved out a bit on both ends which is why i think my throttle won't to all the way back in. I notice this when I run and come in to adjust or whatever the engine idles fine and then it closes all the way like it's supposed to and then it's idling too low and dies should i just buy a new carb barrel slider thing (whatever that thing's called)?

tmodlin

Take the carb apart and use some very fine emory cloth to remove all of the burrs. I had this same problem. Also, like mentioned above, seal the carb into the engine and seal the backplate. If it is leaking you will be running lean and you will trash glow plugs.

PSG-1

yeah i'm going to get some stuff tomorrow to seal it all up. Also i found out that it was just a throttle trim problem. It was trimmed out wrong and not totally letting the throttle go back to idle. Once i hit the brakes however it would allow it to go that extra little bit to idle. I adjusted the trim and now it goes WOT to closed with no problem and no sticking. So it was just operator error as most RC car problems are hehe.

Nitronutt

My Feedback: (2)

For much more smooth operation of any carb on any Savage, switch your throttle return spring location to go between the rollbar and the 90 degree elbow. This works WAY better. It allows the servo to be more effective and also closes the throttle more positively.

tmodlin

I have never thought of doing it like that. I was going to try a shorter stiffer spring but the piece that the 90deg elbo already flexes enough as it is. This should work great.

Nitronutt

My Feedback: (2)

When I first fitted my SH 28 to my Savage, I could not get 100% opening and 0% closing of the carb due to the throttle return spring putting a slight sideways pressure on the carb slide and binding it. I tried operating everything without the spring and it worked perfect. That led me to believe that the spring was to blame. I replaced the stock S-25 throttle/brake servo saver with the updated version that comes with the cam-type steering upgrade.

I didn't want to leave the throttle without some auto closing mechanism, so I figured the best place for the return spring. I drilled 3 holes about 2 mm apart in the rollbar for some adjustability. Like I said above, it was so much smoother and always opened and closed fully after the mod with no binding.

Like you said, it pits the plastic against itself (Spring vs. linkage) instead of putting more stress on the 90 degree elbow mount (Like with a heavier spring in the stock location).

If you want to read more, search either SH linkage issues or SH throttle issues (Can't remember which was my original post).

Polar_Bus

Heres a pic of my Ofna linkage. I tried a few different ways, this setup works the best and the smoothest. (specifically with a good consistant idle)

Nitronutt

My Feedback: (2)

Complete with the duct tape PB? Lol.

PSG-1

Yeah pb i've got the ofna linkage mod on my truck and I love it!! Mine's set up sorta like yours, a little different servo arm but same sorta concept i'll take a pic tonight maybe I think it looks pretty clean myself. I like that other idea of the return spring mounted to the rollbar... how is that thing mounted on there?

Nitronutt

My Feedback: (2)

I kept the end of the spring in a curve and drilled 3 small holes in the rollbar and 1 about dead center in the 90 degree elbow. I then put the smaller end of the spring into the elbow and the larger end into the rollbar. Once I was satisfied with the position, I made both of the curves (on each end) tighter. In 3+ gallons (still working fine when I sold it.) I never had another issue.

PSG-1

That's a great idea man... i'm so stoked!! The problem you explained before about the carb binding is exactly the problem i'm having. When i slide the carb straight in/out it works perfect but when i put the return spring on it sorta pulls the carb to one side causing it to bind at certain places. I've got an extra header spring that wraps around the engine to hold the header on and i think i'll use that.

PSG-1

What exactly is the purpose of that spring anyways? Is it only there to pull the carb shut in case of servo/linkage failure? It slides awesome without that spring. I haven't tried attaching it to the roll bar yet but do i even need to?

tmodlin

It is a mechanical failsafe, unfortunately I dont think it has the power to pull the servo back in the event of a lost signal. I will attach mine to the roll bar just for the added security. I dont see a reason why you have to have it though, especially if you run a fail safe.

Polar_Bus

I race. I can't afford screws, my servos are held in with duct tape.


The tape is for my ice racer in the winter.

Nitronutt

My Feedback: (2)

Yes, the spring pulls the throttle closed in the event of signal loss. Believe me, the spring works really well in the new position I tested it by having the truck not running but everything on. I pegged the throttle. While holding it pegged, I shut off the transmitter. The spring immediately and completely closes the slide - just like intended...only much more smoothly.

jombo

nitronut, i said the same thing in another thread and there are still people out there that they need a failsafe.i have had my batteries fall out of my tx and rx and every time my truck would go to idle.like nitronut said do this test with the motor off and remove the batt out of your reciever while giving full throttle, the spring should return it to idle. the same thing goes with the transmitter turn it off while giving it full throttle it should go back to idle. the only need for a failsafe is a temp failsafe and i just saw one for sale at tower.everything else is electronic mumbo jumbo (imo).

tmodlin

What happens when some dumbas* comes to the track and starts using the same channel as you without seeing what everyone is using? I like the idea of an electric failsafe for that reason alone, plus the fact that it applys brakes too.

Nitronutt

My Feedback: (2)

To each his own T, but in that case, the failsafe may not engage - after all, it didn't lose a signal, the signal got replaced. Whomever's transmitter has better range and batteries will be the controller of your truck.

jombo

thats when you take his controller and break it in millions of pieces,but anyway the only tx that i know of that have interference failsafes are the ppm,zpcm,spcm radios. the tx lets you program a failsafe setting ,so in the event your signal is lost or overtaken by a dumbass it automaticly goes in the programed setting. my jr 783 air tx has this feature,but none of the am or fm radios have them. it has to do with the pulse code modulation(pcm)frequency.dont want to go into detail about it because i'll be here all day explaning it but it does just that,it sends a pulse code and if its broken it sends it into failsafe mode.
my brain hurts im done.good luck i hope this sheds some light on the electronic failsafes out there on why they dont work properly on fm frequency.the best thing to get is a frequency tester and see the channels being used.