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Old 10-16-2007, 01:04 PM
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Default My new Jammin CRT .5

I just received my new Jammin CRT .5 and was wondering what is the best way to break the engine in? The owners manual never states how to break it in. Also, what would be a good glow plug to use in this type of truggy. It has the Jammin .12 engine. Here is a pic next to my Fathers LST2.
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Old 10-16-2007, 02:32 PM
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I always idle 1st 2 tanks..

then 3nd tank 1/4 throttle
4th tank 1/2 throttle

so on and so on.....

never squeeze throttle to possition ease up to it and do 3-5 sec bursts then let it settle down with idle..... and heat up with heat gun to 190 b4 starting each tank... then let cool all the way at BDC....

again this is how I do it everyone does it diff.. and has thier own opinion... i had that motor for my pro.. its a good little motor.. i just upgraded to the JL red dot offoad...
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Old 10-17-2007, 08:10 AM
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Originally Posted by glock19er
I just received my new Jammin CRT .5 and was wondering what is the best way to break the engine in? The owners manual never states how to break it in. Also, what would be a good glow plug to use in this type of truggy. It has the Jammin .12 engine. Here is a pic next to my Fathers LST2.
Where did you find the white wheels ? Looks sick !!
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Old 10-17-2007, 08:14 AM
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the RTR comes with white wheels
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Old 10-17-2007, 08:36 AM
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Is the RTR comes with standard servo? Hows the servo? can you show us the picture without the body. Thanks
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Old 10-17-2007, 08:38 AM
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Save some headaches, replace the front top arms with lunsford turnbuckles. My son broke three the first day at the track, and there was no hard impact, just brushing the pipe. Since I made the change, no problems at all!! All it takes is 2" turnbuckle, some ends and screws!
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Old 10-17-2007, 08:45 AM
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Pics of the servo set-up PLEASE.....are they both Standard ?.....Also ill 2nd what David Wall is sayin about the upper arms...they need some attention.
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Old 10-17-2007, 01:28 PM
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Do you have a part number for the Luns turnbuckles? One more question: The glow plug that came with the car came with two little brass washers. Do I need to use both or do they just include an extra one? It is an OFNA glow plug. Here are the pics you requested.




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Old 10-17-2007, 02:30 PM
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Very Interesting....wonder why they didnt do that in the first place.... dumb Yammin...and the pipe is no longer a 1 peice style header.....guess they gotta cut costs somewhere......Looks good tho glock19er thx for the pics.
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Old 10-17-2007, 03:58 PM
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Only use one spacer on glow plug! they give u 2 just in case u lose one.. its under OFNA's common questions on their site...
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Old 10-17-2007, 04:08 PM
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Originally Posted by Integra
Very Interesting....wonder why they didnt do that in the first place.... dumb Yammin...and the pipe is no longer a 1 peice style header.....guess they gotta cut costs somewhere......Looks good tho glock19er thx for the pics.
I've never seen a 2-piece style header.

You break it in just like any other motor. Your father should have all of that information.
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Old 10-17-2007, 10:37 PM
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annie- a 2 peice is like what you see on most 10th scale gas trucks. where you need a coupler. one peice is where springs hold the manifold and pipe together like on 8th scale buggies and truggies.
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Old 10-17-2007, 11:04 PM
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The Jammin .12 uses a short glow plug. If you are using a long glow plug you need 2 washers. That may be why they used 2 washers.
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Old 10-17-2007, 11:10 PM
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One other thing. It is very important that you have at least 210 degrees while idling the motor. Anything less and you are putting a lot of stress on the rod. This is the method I use to break in my motors.

ENGINE BREAK-IN

Engine Tempering & Engine Break-in
Reprinted From S-Grid with Stephen Bess's permission
Below info is from this page: http://rbmods.net/enginetempering.php

If you are still idling at least a tank through during break-in, you're using the old-school accepted method (still works well for some!) but it's not the method that the top engine guys (Ron Paris, Dennis Richey, Rody Roem, Michael Salven are just a few I've spoken personally with about this) recommend anymore.

From the very 1st time you start your engine, plop the car on the ground & begin running it in a parking lot in 2-3 minute intervals, tuned only *slightly rich* getting the temps up in the 200F range on a normal day. Every 2-3 minutes, shut the engine down & let it cool completely with the piston at BDC (bottom dead center), and then fire it back up; continue this cycle until you've run 15 min or so, and then bump up to 3-4 minute intervals. Vary the RPM and don't be afraid to get the temps in the 200's. What you want is heat cycling of the components without the incredible stress that comes with breaking an engine in when it's overly rich & cold. After cycling the engine in this manner for about 20-25 total minutes, it'll be ready for the track and race tuning. I realize this method goes against the old-school "idle on the box" routine, but you'll be amazed once you've completed this break-in routine, your engine will still have amazing pinch w/out sticking at the top AND your engine's compression will last far longer than it will with the "old school" method.

You say you run the engine at "factory settings" for the first FIVE tanks? That alone causes lots of stress, as the factory engine settings are very rich on every engine I've ever owned or tuned. The piston & sleeve haven't expanded to operating temps, and every time the engine turns over, the piston slams into the pinch zone at TDC. The not-so-surprising result can be a cracked con-rod at the crank pin--that's where the majority of the stresses occur as the engine turns over. I've only heard of about 6-8 engines breaking con-rods, and they're ALWAYS during the first gallon...and almost every time it's because the guys have performed the break-in procedure you described. Doesn't seem like a mystery as to why it's happening. Drawing out the break-in routine really stresses the engine & actually wears away compression along the way. This method I've outlined will feel weird at every step, but after you try it once, you'll notice a big difference in your engine's performance & lifespan.

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Old 10-18-2007, 04:35 AM
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Originally Posted by micrors4guy
annie- a 2 peice is like what you see on most 10th scale gas trucks. where you need a coupler. one peice is where springs hold the manifold and pipe together like on 8th scale buggies and truggies.
Don't mean to be nit-picky but you said header, not pipe and header.
There are no two piece headers out there.
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