new to nitro and having problems after start

[thetrixstr]

hello I'm brand new to nitro, used to rc electrics in the 90s.
I have someone who gave me a nitro rc, its a maximus st? not sure if that's traxxas or not. He built the car and put a engine in it and said it had been cleaned and rebuilt but had not started it. I just learned about glow plugs and and getting it started. I started it this evening after work and it cranked right up but also seemed to be getting a ton of power so I picked the rear end up and tried the brake on the controller and it almost stopped the tires from spinning, then it shut off. I restarted it and let the tires spin while I tried adjusting the trim for the throttle on the controller and it didn't seem to help, but at this point I noticed the tires were spinning extremely fast and what seems to be fuel was pouring out of the exhaust or spraying I should say. so I pinched the fuel line to stop it. I also noticed that my almost half full fuel tank was now virtually empty. I then adjusted the low speed screw thinking it may have been way to "open" and re-cranked. this time it seemed to have even more "power" headed to the wheels as the tires started to come off the rims. I quickly adjusted the high speed screw to see if that helped and it made it worse the engine revved even higher so I undid the adjustment and it started to rev even higher before falling back off slightly before cutting off from being completely out of fuel. now I have a bunch of fuel all over the porch and not sure what action I need to take to at least get this running so I can "tune" it? the engine is a FR 18? not sure how to proceed but afraid that I may burn it up....not sure how to adjust the high and low to factory or how to adjust them both to closed so I can "open" them up slowly to see how it goes. sorry for the long post, any help would be greatly appreciated.....

 

[Certified Mike]

https://www.rcnitrotalk.com/forum/threads/nitro-tuning-tips-and-tuning-flow-chart.60832/
There is a TON of info including the info you are looking for in this post. Please read thru it all. After you are familiar with this, fire out some more specific questions and I/we will be happy to get you straightened out! You are in good hands now!
Just as a beginning to what you need to be doing... Set your carb gap. It should be set at approx 1mm. Use an Allen wrench if you don't have anything else to gap it correctly. The post will show you where to find the gap set screw. After that is set, be sure that your throttle rods are set so that neutral is REALLY neutral. No gain or back pressure on the carb, just touching.
Next is to set the carb back to manufacturer's beginning settings. This is usually a very rich setting and used because it is often where ppl need to get back to as they are familiarizing themselves with carb adjusting during motor break in procedures.
This will require identifying the engine (and the kit itself would be helpful)
Please post pics of the rig. The engine, the car itself and any close-up of markings etc.
Good luck!
We will be here when you're ready!

 

[thetrixstr]

https://www.rcnitrotalk.com/forum/threads/nitro-tuning-tips-and-tuning-flow-chart.60832/
There is a TON of info including the info you are looking for in this post. Please read thru it all. After you are familiar with this, fire out some more specific questions and I/we will be happy to get you straightened out! You are in good hands now!
Just as a beginning to what you need to be doing... Set your carb gap. It should be set at approx 1mm. Use an Allen wrench if you don't have anything else to gap it correctly. The post will show you where to find the gap set screw. After that is set, be sure that your throttle rods are set so that neutral is REALLY neutral. No gain or back pressure on the carb, just touching.
Next is to set the carb back to manufacturer's beginning settings. This is usually a very rich setting and used because it is often where ppl need to get back to as they are familiarizing themselves with carb adjusting during motor break in procedures.
This will require identifying the engine (and the kit itself would be helpful)
Please post pics of the rig. The engine, the car itself and any close-up of markings etc.
Good luck!
We will be here when you're ready!

thank you very much for the help and advice! I changed the gap down to what I believe is 1 mm and tried re-cranking. it did start and run but also starting spraying fuel again so I shut it down again. I made sure the exhaust was as tight as possible, then pulled the plug to relieve the pressure. reinstalled I cranked it again and after a few seconds it revved really high again so I pinched the fuel line to kill it. I noticed the hsn was very loose so I gave it a couple turns in to "tighten it up" and recranked then once again it started and revved the highest I've seen thus far and so much so that I watched the high speed needle back itself completely out of the shaft and fall out onto the ground. shut down I took it back inside. I assume I am missing a rubber o ring for the hsn from what I hear. I also noticed that the pinion gear is now stripped of virtually all teeth so the gap wasn't set correctly. all the hobby shops around me have now went out of business, so I can't just pop in and get a new one. so I'm stuck now until I can order online what I need and hope its correct and I don't run into the same problems again. in the meantime I have tore apart the motor and tried cleaning it and giving it some wd40. same with the carb, just not sure about the o ring where it should be etc..
it can be frustrating but I plan on having a running car someday so ill keep chipping away at it....thanks again I'm sure ill be back with more issues

 

[cbaker65]

thank you very much for the help and advice! I changed the gap down to what I believe is 1 mm and tried re-cranking. it did start and run but also starting spraying fuel again so I shut it down again. I made sure the exhaust was as tight as possible, then pulled the plug to relieve the pressure. reinstalled I cranked it again and after a few seconds it revved really high again so I pinched the fuel line to kill it. I noticed the hsn was very loose so I gave it a couple turns in to "tighten it up" and recranked then once again it started and revved the highest I've seen thus far and so much so that I watched the high speed needle back itself completely out of the shaft and fall out onto the ground. shut down I took it back inside. I assume I am missing a rubber o ring for the hsn from what I hear. I also noticed that the pinion gear is now stripped of virtually all teeth so the gap wasn't set correctly. all the hobby shops around me have now went out of business, so I can't just pop in and get a new one. so I'm stuck now until I can order online what I need and hope its correct and I don't run into the same problems again. in the meantime I have tore apart the motor and tried cleaning it and giving it some wd40. same with the carb, just not sure about the o ring where it should be etc..
it can be frustrating but I plan on having a running car someday so ill keep chipping away at it....thanks again I'm sure ill be back with more issues

If its a duratrax maximum ,then that's a very old model ,the O-rings in the carb are probably rotted & gone!
Duratrax usually were good about parts support an also made their own hop-up parts ,so it maybe worth
doing some research through the Duratrax company to see if there is parts still available for that model.
More than likely ,you will need a new needle.You also might can check ebay for parts ,sometimes people
sell new old stock parts.

No tune guide or a tune is going to help if you got a rotted carb O-rings!...

 

[cbaker65]

Go to duratrax.com ,I just came from there an looked at the manual.
When you go to the site an look up down loads at the bottom of the page ,then to manuals ,you will find a spot that says discontinued products
written in blue words ,click there an you will see the Maximum trucks.

If it is the little 12 size engine ,it says the HSN needle is only about 1 1/2 turns out from closed.

 

[Certified Mike]

Yes!$ you 100% need the orings on the needles!!! I would inspect carefully to see that the threads aren't stripped out. So long as they are good and the carb all seems to be operating properly, Def start buying the parts it needs. The manual will tell you what you need. You really should have the manual and read thru it until you are familiar with the kit.
As far as installing the prints and needles... Be sure to pick up some "associated electronics green slime" that is the truck stuff for getting the rings in without damage. It will help to keep them from,drying out as well. Until you do get the rings, there is no sense in trying to tune. It simply will not work. When you get things straight, let us know and we will get you going for sure!
Glad to help and glad to know my post helped to get you closer to your goals!

 

[thetrixstr]

Go to duratrax.com ,I just came from there an looked at the manual.
When you go to the site an look up down loads at the bottom of the page ,then to manuals ,you will find a spot that says discontinued products
written in blue words ,click there an you will see the Maximum trucks.

If it is the little 12 size engine ,it says the HSN needle is only about 1 1/2 turns out from closed.

Thanks I was wondering what happened to those guys, I guess they are more of a charger esc company now? I didn't see the link when I visited but I will certainly go back and get that manual. that's a huge help in itself. from the pics I've seen it looks like the motor I have is the stock 12 motor ( same color head/shape etc. )thanks again I really appreciate it!

Yes!$ you 100% need the orings on the needles!!! I would inspect carefully to see that the threads aren't stripped out. So long as they are good and the carb all seems to be operating properly, Def start buying the parts it needs. The manual will tell you what you need. You really should have the manual and read thru it until you are familiar with the kit.
As far as installing the prints and needles... Be sure to pick up some "associated electronics green slime" that is the truck stuff for getting the rings in without damage. It will help to keep them from,drying out as well. Until you do get the rings, there is no sense in trying to tune. It simply will not work. When you get things straight, let us know and we will get you going for sure!
Glad to help and glad to know my post helped to get you closer to your goals!

Yes indeed you guys are getting me on the right track! green slime huh? sounds like a handy thing to have, the last thing I need to do is damage it right off the bat putting it in.....thanks again guys i'll keep you updated soon as to how it goes. small question to add to this, will duratrax sell and ship directly or will I have to order from a third party given them getting out of the kit game nowadays? figured id ask before digging....

 

[cbaker65]

Thanks I was wondering what happened to those guys, I guess they are more of a charger esc company now? I didn't see the link when I visited but I will certainly go back and get that manual. that's a huge help in itself. from the pics I've seen it looks like the motor I have is the stock 12 motor ( same color head/shape etc. )thanks again I really appreciate it!

When a nitro rc sits for a long period of time ,its not just the engine you have to clean an do maintenance on.
The tank an the internals could be plugged or rotted as well!
But if you got plenty of fuel going out of the pipe ,maybe too much ,then the needles could be open too much.

The HSN needle on that engine should not ecceed past 2 turns from closed ,I guessed at 1 1/2.
If the o-ring is still in tack ,you can try to put a little vasaline on them.
There is some little tricks out there that you can use.
Make sure that the fuel lines are good an in their proper places an none of them leak.
Make sure that the fuel tank does not leak ,an holds the back pressure from the muffler.

 

[Certified Mike]

Just so you are aware, there should be a fine mist of gray smoke (which is kind of unburned and exhaust all at once) from your exhaust. It sounds to me like you have WAY too much but a little is ok... A LITTLE!!!
If you are sure that you're missing that o-ring, you need to get it back in there. It will never run propper without it. The green slime helps to prevent tearing and sticking on the o-ring as it is installed as well as future adjustments. The green slime was designed for orings in shocks and it seems that it's the best stuff for them. Vaseline will work as a lube but it seems that for shocks and for these needles, the slime is the preferred method.
I don't know about direct shipping from duratrax.

 

[ninnon]

Seems like the link to the tuning flow chart give a good read at the other guide too. Once you understand what's going on, you'll get your head round it in no time.