JohnP2

The O.S. .25xz break in process has definitely been different than the others. While this is my seventh engine to break in, I still get a little nervous with each one (probably always will). Especially since this is my first "competition" engine.

First and foremost has been the starter box. While not necessarily part of the engine, it IS the only way the engine can be started (as is), and thus far the starter box has been the bane of my existence. There are a myriad of factors for this:
1. The starter box did not come with pegs. Thus aligning the flywheel is a little more challenging.
2. The compression on this is uncanny. Even with the glow plug OFF and the engine heated up, once it is at the top of its stroke, I have to use a slotted screw driver to get the piston to BDC. I know compression is a good thing, but I do hope once the "run-in" (as OS calls it) is complete, it does loosen up some.
3. I primed this engine only ONCE (the first attempt). I've learned not to do that again. Due to its compression, this is a "self-priming" engine. By that just turning the flywheel by hand. you can see fuel being sucked in to the carb.
4. The started box can ONLY turn over the car if the 7.2 batteries are at peak charge.
5. OS run-in method is a little different than what I'm used to, but I very much respect their advice, so will follow their method without deviating from mine much. The net-net is with theirs you goalmost. I k2/3 a gallon of fuel before tuning it.
6. I'm excited about tuning this I know people complain about it, but I LOVE tuning. Especially new engines as that is when it really comes to life.
7. I bought a 12v battery and hope this makes a huge difference, as there is no way I can take this thing to the track and hope I get lucky and get it started. I will be contacting OFNA to find out why no alignment pegs, as Ithink those would help a lot.
8. Using the starter box requires some touch. I've learned that if you get the wheel to terminal speed, then barely lower the flywheel onto it, that works best. As noted, it is one of those things you have to develop "feel" for.
9. Today I get to finalize the tune(after about two more tanks of break in). I got a sneak listen the last tank, as when it ran out of fuel it leaned itself out a little and oh it sounded sweet!
10. My son it breaking in his Losi 8 today. He knows how to break in, what the purpose is, cool it at BDC,etc., but hope he has better luck with his starter box than I do. At least his has pegs. ;-)

supertib

stick packs suck for a starterbox

12V gel cell is not enough for a OFNA truggybox...you really need 4S lipo to see what that box can really do...the difference from a 12V gel cel to a 4S lipo is almost double the power, and from the stick packs will feel like triple the power........

Ttowntoolman

I agree, stick packs suck for any bump box in my opinion. Are you sure it is wired so you are getting 14.4 volts to the motors or just 7.2?

I never let my 25XZ run out of fuel since it was new. I may be too anill about it but I think it takes life out of an engine because it has run dry. I guess if your fuel is good quality with a good oil content with castor it wont make any difference. I try to NOT run out of fuel and shut my engines off via flywheel stoppage. I have 12 plus gallons on my engine, running great, no signs of getting tired at all yet.

Sorry to hear of your frustations, but you seem to be handling it well and I am sure you will be well rewarded with much satisfaction in the end. Good luck and keep smiling!

supertib

you have no alignment pegs ? are you serious ?

dude you need to slow down here if you have no pegs...your going to destroy your starterbox...

Ttowntoolman

Oh yea, good catch, I did not read that first time over this thread. Without pegs of some sort, it's just poke n hope!

supertib

I couldn't even imagine trying to breakin a tight engine with no alignment pegs especially using only stick Packs.....poor guy would be pulling his hair out and probably destroying the starter box in the process.....

little details can kill you..things novice wouldn't think would matter much can actually be the difference between success and catastrophic failure...

Ttowntoolman

Yea the devil is in the details for sure. I thought alignment was gone over in another thread as part of the set-up. It's all good, part of the learning curve.

Ttowntoolman

Wow, I can actually hear that OS with it's narly cackling purr coming down off a high speed pull. I got to go home and fire mine up in the garage now, all geeked up.

JohnP2

I've been very careful with it (without starter pegs), I assure you. In fact, after writing that post, I went to start it and it fired up the engine almost immediately., Is ideal, obviously not, but it is what it is. I just have to go slow and ensure it is lined up correctly and then lower it. If it's not lined up, I know pretty quickly as I can see the flywheel from the top and I immediately remove it. I am a little ticked as it was SUPPOSED to come with pegs, as the diagram shows it. I went ahead and ordered some as I can see where it will certainly help.

The good news is that at least I know there is an easier way, and I can see the advantages of the starter box once it becomes easier. ;-)

JohnP2

So I finally got it tuned, and all I can is WOW!

Once it got to the point it was tuned well, when it started hitting the pipe I was actually getting a little nervous it's so fast.. Because this will be a track-only vehicle, I doubt I will ever get it top speed  on the track...but it's good to know I have that power if I need it. As for the kit, it handles like a dream. I need to go through and ensure everything is locked and loaded, and there are a few tweaks I need to make to it, but I'm thrilled with the results. I was a little worried the cost would not be worth it (i.e. it would be just another car) but it is more than worth it!

HerrSavage

I've only ever run stick packs in my starterboxes, and have never had a problem - even with really tight engines. I've never had them die on me either from too little juice. I'm fairly careful about making sure they're always charged - but they are absolutely reliable for me in my experience. Extremely low on my list of things I need to upgrade in RC... Not even on the list at all to be honest. More like on the "if it ain't broke, don't fix it" list...

Both pairs of stick packs in my two current starterboxes are over two years old too. Middle-range 3300's, that's it.. (The stick pack in my Losi Spinstarter is four+ years old.. [X(] )

nitroexpress

Never had a problem running stick packs in my starterboxes. Sure 4S will spin faster, but an engine will either start or not both ways. But it got to the point that the price of decent stick packs got excessive. I tried some EBay stick packs, but they lost capacity in a short time. So it got more cost effective to run a 4S LiPo. 4000mah is more than enough, hardcase is not needed. Although some find 20C is adequate, I usually go for 30C. Ialways use a LVA for safety since they are less than$6.HobbyKing 4S and you're good togo for $30 - $35

supertib

I am opinionated against stick packs.... seen way too many guys at the track struggle with their stick packs trying to start a engine...Probably a good part of the issue is nobody was using fresh new stick packs, they usually dig out some old garbage packs they had from 1995 just to save a few bucks not having to buy a proper battery.....ends up costing them more frustration and headache then it was worth to buy a proper battery......... Been a few years since I have seen anyone with a fresh, good quality stick pack ! usually all we see are old worn out garbage dug out of the scrap RC box in the closet...

supertib

Herrsavage and Nitroexpress do you guys use the OFNA Blue truggy box ?

the reason I ask this is because thru my experiences the twin 775 motors of the Blue box will struggle with weaker power sources....The motors it uses are power hogs, and if you try to run weak batteries the box's performance drops off drastically, Not only that but the motors can get excessively hot....I Am not sure why this happens, but you can damage that box if you batteries are unable to provide adequate power........I have multiple starterboxes, mostly OFNA's..but none of them have had any issues with lower power supply..my twin 550 boxxes run all day on a 12V gel cel... However the OFNA Blue box(twin 775) will not run well on a 12v gel cel at all..The motors overheat and torque is terrible...on a 12V gel cel my 550 box blows my 775 box out of the water......... However once you flip both the 550 box and the 775 box over to the 4S Lipo the 775 blows the doors off the 550 box.... That OFNA Truggy box needs power ! if you dont give it enough power you will cook it......But hey what do I know about this stuff !

nitroexpress

I have 2 OFNA Truggy starter boxs (twin 775 motors)

OFNA 1/8 Starter Box (chrome top)w/Power Panel (single 12v motor). Not sure what size it is considered.

supertib

did you run your 775 boxxes on Stick packs or gel cels ?

I have one of those old single motor boxxes too.....maybe the motor would be a 1050 LOL ! they are massive....

HerrSavage

Both mine are Ofna truggy rebrands (SMD) with dual 775's, running with stick packs that are a good two years old, if not more... Yes though, I do charge them pretty fequently(probably more than necessary..) Had another one previously(that I sold with a buggy), also ran with stick packs for a good two years..

Even the old TT single-motor startbox had the guts to start most anything with stickpacks.. Ran that one for years too..(then sold it as well) My two current Ofna boxes though are plenty sufficient to do everything I need them to do.

nitroexpress

I never tried a gel cell in the the truggy boxes. Not sure if the truggy box is largeenough for one.

At present, I run one box with sticks and one with a LiPo.

For peace of mind, I run this $2 Low Voltage Alarm on the LiPo.

big JC

My Feedback: (1)

I recently got a twin motor ofna box ( got tired of throwing belts on the losi box real quick) and switched from stick packs to a 4s lipo. What I don't understand is when youalreadyhave a lot of money into the hobby why not spend just a little more in order to take full advantage of the expensive gear you already own. You can get a descent quality 4s lipo for araound $40 now. Not only will the box have more power on 4s, but it will last you an entire race weekend without having to worry about charging it. Furthermore, as already stated, ifthe motors onyour starterbox are trying to pull more amps than your stick packs can deliver you will burnthe motors up.

big JC

My Feedback: (1)

oops

SyCo_VeNoM

you mean the batteries right?

nitroexpress

When my stick packs are heavily used and start to go flat, the motors slow down. Obviously, the motors want more amps than the used up batteries can supply. In this case, I really doubt that the motors are in danger of damage. Over discharging can damage the batteries, but not the motor. The only thing that will burn out the motors would be when the possible supplied amperage is high and the motors are put under an unreasonable load.

For me,2 stickpacks or 1 4S LiPo, they bothdo thejob. I go with the cheapest combo.

I'm not cheap, I'm thrifty.

big JC

My Feedback: (1)

Not an expert by any stretch but guess the whole system would take a lot more heat? What I can say is the motors on both my boxes get subsantially hotter when using my old stick packs versus my lipo. The cause and effect of this I am only recently learning.

big JC

My Feedback: (1)

That makes sense, wandering now if one of my stick packs has a short or high resistance

supertib

At the end of the day whatever works.....