Nitro engine break in tips wanted.

[justo316]

Ok, I'll be done building this savage SS soon. Gonna break the engine in this arvo. Need some tips on what not to do...

The instructions say that for a few of the tanks, to run the truck up to full speed with the wheels OFF the ground. Is this safe?? I guess it must be if they say to do it, but I was always under the impression that it was bad to run nitro engines with no load on them.

[Dlux]

Whoooooooaw, easy tiger. Full speed with wheels off the ground! I've never heard that before. Unless they've changed the process of breakin in engines, I wouldn't be doing that. Is this the SS with the 25, 26 or 28 engine? Makes no difference really. Dude, do a search on the savage-central website, those guys there have everything you wanna know about the savage. Your post asks for what not to do, so I won't go into what I think you should do. :p

[BALISTC]

OK this is how I run my motors in.

First start, make sure the needles are set rich.

Put a tank of fuel in, and start the motor.

Let it idle until it reaches operating temp (depending on needle settings this will be different for every motor. Keep idling it til it wont get any hotter, this should be done with temp gauge),

Then shut the motor off. Make sure the piston is not at TDC or it might get stuck.

Let the motor cool down completely, until its stone cold.

Repeat this process 5 or 6 times.

It might take a while to do, but if you want the engine to last the longest period of time, this is an important step.

After you do the heat cycling, start driving the truck around with normal amounts of throtte input, but low revs. Drive it normally, dont be a baby with it, as long as you dont rev the nuts off it. Make sure the motor doesnt get too hot.

Every tank, turn the needle in half a turn. Keep doing this until the needles are set where you want to set them.

Hope this helps :)

[justo316]

Cheers guys.

About the instructions, they are for the nitro star s 25. Basically says (at step 7) "with the tyres off the ground, use the radio to slowly increase the throttle until it reaches full speed, then release."

[Dlux]

Another tip is (and this could be an over kill), when you are heat cycling the engine for the first few tanks, cover the heatsink with alfoil. This gets the temp up a bit while still running it rich. Oh and make sure the idle needle is set right if you have the wheels off the ground so that it doesn't engage too much.

[justo316]

I can't get this thing to stay idling at the factory settings dammit....

[justo316]

To be precise, it idles roughly, then eventually speeds up and cuts out.

[opAsx]

i think hes trying to

[justo316]

yeah, trying to break it in now.

[Dlux]

Turn the idle screw anit-clockwise a little at a time until the wheels stop turning quickly. Get to the point where the clutch is about to engage while idling.

[justo316]

all the needles are set as per the instructions.

Tried turning the idle screw anti-clockwise to stop the wheels turning, but the engine keeps cutting out and won't start unless I give it some gas.

[justo316]

basically, we can keep the engine going longer if we idle it up at first. Then after it warms up a bit we can turn the idle down again, though not anywhere low enough to stop the wheels turning. Occasionally the engine speeds up and goes a bit psycho by itself, eventually cutting itself out. If bychance, it idles for more than 10secs nicely, it will eventually cut out as well.

Giving up for today. Hopefully someone has some ideas (or I find some answers) so will give it another go tomorrow.

[Bowling Ball]

I have never run Nitro but I have fixed 2 stroke whipper snippers.

From what you say, its being starved fuel. Sounds like it might not be rich enough. The other thing I would look at is the hose from the muffler to the tank, as you said it only runs for a bit then dies, it might be fuel flow.

I am guessing, its not in front of me.

BB !amazed

[justo316]

I thought it was running lean as well, but the instruction settings are supposed to be overly rich for breaking it in? I will try richning the both HSN and LSN tomorrow.

Also, I thought the occasional increases in revs might be due to air bubbles in the fuel line? I can't seem to get rid of them.

[Dlux]

Is the LSN flush with the housing. Is the HSN about 4.5 turns out? It's frustrating ain't it but once you got it sorted.............oh that nitro fume.

[justo316]

LSN is 3 turns out. HSN is 4.5 turns out. Hard to gauge a 2mm setting for the idle, but judging by how fast it's going, seems to be a bit too much. Although, from photo's I've seen, mine looks less.

Tomorrow I will try get it started and richen the HSN to try control the excessive rpm.

Thankfully this isn't my truck otherwise I'd be really pissed off. At least I can go drive my Revo if things get really frustrating :P

[Dlux]

I just hope that others that read this don't get turned off by nitro...................it can't die, it just can't die :( . It's a learning process and once you know a bit, it'll have you hooked (for a while anyway).

Justo good luck tomoro. Actually, stuff tomoro, go annoy your neighbours and start that baby up..................I sure as hell did when I first got my truck, then again when I got a new engine, then having the compressor on etc

[justo316]

haha....Mr Gold keeps us up at night ;) But I don't sleep so doesn't affect me.

[BALISTC]

Justo, if you have probs, give me a call tomorrow and I'll swing past after work and have a look..

[justo316]

Cheers mate. I'll keep that in mind.

[James]

Mr Gold. hah, chelsie drives that thing around these days. Dans other car, Le RX7 is in getting a GT35/40, manifold, microtech, etc. nutzoid!

hope u sort ya nitro justo, hang in there, there's more than enough knowledged ppl to help ya out!

[justo316]

Yeah, the rx7 is niiiice. I get a few people asking if its mine....probably something to do with jap cars and asian guys... :P

[justo316]

Woohoo! Using the HSN to control the high revs worked well. Kept it iding nicely for the rest of the tank we weren't able to do yesterday.

[justo316]

nah, I had it as rich as the instructions told me (4.5 turns out). But as the motor broke in it just kept speeding up and I couldn't get it to stay started if I dropped the idle down. So, today, I ran the HSN out to 5.5 - 6 turns and it kept it under control.

Just ran the second tank through it with no problems. Doing slow circles as the instructions tell me. Will give it a little rest to try incorporate balistcs ideas, and then go for my third.

[Bowling Ball]

Good glad you got it sorted Justo.

The manual is only a guide. Different atmosphere, temp, fuel mixture can effect the way the motor will run.

Good learning curve for everyone in this thread :)

I thinking of going gas for a basher myself

BB !amazed

[justo316]

Yeah, hopefully some good points were made along the way.

I found that whenever I found any "break-in guides" they never really say what to do if something goes other than planned.

[Dlux]

Feel the nitro BB, step over to the fun side !alien

[Aj]

Good to hear! might be going for a bash on sunday if you want to come along. add aj @ dinfw.com to msn :)

[justo316]

I would , but it's my brothers truck and he's got it now. My Revo is in the pits waiting for parts (if they ever arrive!).

I think it's gonna be rain/hail/wind this sunday too.