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-   -   One last first fire up question. (https://www.rctech.net/forum/nitro-off-road/314763-one-last-first-fire-up-question.html)

Devilbrad 07-25-2009 05:29 PM

One last first fire up question.
 
I have never fired up a nitro engine, let alone a brand new one. What is the best way to prime the fuel system? Thanks.

LordAnubis 07-25-2009 06:41 PM

I'm new to this stuff too (got my first nitro rc a month ago). There are 2 ways of priming the engine that I know of.

1) remove the backpressure line (the fuel line that is connected to the exhaust) and blow into it gently, till you see fuel going into the carb. A few things to keep note with this method... remove the hose only from the exhaust end... so basically you are blowing air into the fuel tank (via the hose). Also try and make sure you don't blow any spit into the line.

2) Simply put your finger over the exhaust, and pull the start cord a few times (as if you were starting the engine). This method works for me with my pull start, but not sure how well it'd work with other starters (roto, box)... i'm sure it'll still work well. Note with this method the exhaust may be hot (especially once you start it up and it's been running for a while) so be careful.

I use the second method.

One more thing incase no one has told you... starting for first time can be quite frustrating. The engine is new (i'm assuming) and will be really tight. If you've checked everything (car is on, and remote working properly, glow plug is working, engine is primed) then the car should start within about 10 short pulls (remember not to go he-man on it if you have a pull start... they are pretty easy to break if you give it to it). If the car doesn't start within ten pulls, it'll most probably have flooded, which at the moment is a kind of good thing. Here's what you do once you can't get it started and you've flooded the engine.

- Once the engine is flooded (if you don't know what a flooded engine is it's basically you get to a point where the pull start becomes hard to pull... it'll feel like it's blocked up by something) remove the glow plug and the glow plug washer, get a rag and put it down the heatsink, then pull the starter a few times. This will push the flooded fuel out onto the rag... Note the rag is there just to stop fuel spraying everywhere (mainly stop it getting into your eyes) so just cover the top so the fuel will get soaked into the rag.
- Now with the engine un-flooded, make sure everythign is fine again (car is on, and remote working properly, glow plug is working, engine is primed) and try to start it. Sometimes starting an engine is easy after you flood it. If it doesn't start within about 5 pulls stop.
- Now you'll need a heat gun/hair dryer. If there isnt one in your home, jsut go out and buy the cheapest one you can find. With the hair dryer jsut heat up the engine (not the heatsink... but heat the actual cylinder part of the engine) jsut warm it up for a minute or so and if you pull the starter you'l notice that it gets easier to pull (due to the heat expanding the cylinder). Now once it's a bit warm just try starting again and you should notice it's easier to pull firstly, and it should start pretty easily (within 5 pulls).

Ohh and all the while... make sure you are changing your throttle trim... don't be afraid to put the trim as high as it goes... just make sure you are holding the car when it starts... otherwise it'll shoot off, and be ready to turn the trim down once it's started.

Well that was long but hope it helps you.

megasaxon 07-25-2009 06:50 PM

I reccomend using a heat gun or hair dryer to get the motor up to around 170-180 degrees before you fire it. It will start much easier, plus it allows the sleeve to start to expand a bit, helps with the logevity of the motor.

On a new motor, i would use the pressure line technique, or after you've warmed it good, you can use the pipe technique.

Also, i'm sure you've read the breakin instructions thoroughly a couple of times through. don't let the car run out of fuel, kill the motor at the end of the tank by puting you finger on the flywheel. as long as the idle isn't too crazy high, it won't hurt you at all. If you are a little afraid of doing it, use a screw driver end, or tip of your shoe to do the same. Always make sure the motor is at bottom dead center between tanks. You'll be able to tell by turn the motor over, you'll feel it go up into the top of the sleeve and then back down.

Devilbrad 07-25-2009 06:56 PM

Thanks guys. I have read the break in bible and will be follwing it, I just dont recall a fuel priming method. I'll do the pressure line method! And I just might video my first fire up, LOL

thelucky13 07-25-2009 07:16 PM

I've used both ways, and they both work okay. Never used a heat gun/hair dryer though. Sounds like a pretty good idea

Devilbrad 07-25-2009 07:21 PM


Originally Posted by thelucky13 (Post 6116516)
I've used both ways, and they both work okay. Never used a heat gun/hair dryer though. Sounds like a pretty good idea

You should come over and blow some hot air on it! :D

thelucky13 07-25-2009 07:27 PM

if someone wouldn't have ignored me i woulda had it running last night!

Devilbrad 07-25-2009 07:35 PM


Originally Posted by thelucky13 (Post 6116554)
if someone wouldn't have ignored me i woulda had it running last night!

UM...


Originally Posted by thelucky13 (Post 6116516)
Never used a heat gun/hair dryer though. Sounds like a pretty good idea

Yeah Brian, come break in my engine!! :ha::D

davidg01234 07-25-2009 07:38 PM

Take off the back pressure line and blow in it till it gets to the carb

thelucky13 07-25-2009 07:38 PM

sorry i've broken in plenty of these engines. Never had a problem with a single one of them :D

NDHotbodies 07-26-2009 07:59 AM

the 1st thing you should do is when you get your new engine is put some ARO in the engine to let it set for a day or two. before you go to stert it up, pre-heat the engine as said before,I go to 170/200feh. I feel most of the time you realy don't have to prime an engine if you pre heat it 1st. we have engines on thier 2nd and 3rd seasons and still work great and we still pre heat them,, saves alot of wear and tear on them...


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