break in reassurance

[kejseren]

Hi!

yesterday i ran my new jato (brand new) for the first time, doing the break-in steps traxxas recommends.

I can find variations of this question around the forum, but i can't find an exact answer to this question, hence why im asking (ive looked cant find any).

My question is:

how can you ever know, if you did the break-in correctly? I like to have some sort of reassurance...
Reason im asking is i had problems with the piston getting repeatedly stuck at TDC, the fit was _very_ tight. We came up with the conclusion that it was too cold outside. 55 degrees + a rather stiff wind, which made the actual feel even colder. Even after the break-in, we couldnt get it started and decided to head home and try to blow at the engine with a hair dryer. After heating it up, there was no problems. Fired up first burst of the ez-starter and idled well. No time to run anymore though so we turned it off and called it a day.

After this i havent run it yet. Its currently in my room at normal room temp. and i can still barely push the piston around with a screwdriver.
Ive run some afterrun oil through it as well to get it lubricated.

Is it still too tight? Do i have to run the break-in process once more? How can i know that i did the break-in correctly?

Thank you in advance!

[RC-Fan]

if you did the break in according to traxxas instructions you should be fine, the resistance in the piston is because it is a new motor, and it has a lot of compression, when the piston-sleeve is worn out, the compression will be lower also the resistance.

[slayer17]

To answer your question is simple. If you broke in the engine proper and the pistson and sleeve has a perfect fit, you can take a drop or two of silicone platelets, I use (Midas Touch Lubricant) from Boca bearing drop it into the cylinder. I turn the engine over several times to embed the silicone platelets into the piston and sleeve then I use a tiny bit methanol to clean most of the oil residue out. I put the glow plug in and I check the seal of the liner by to rock the piston back and forth at TDC Top Dead Center and after about 15 times and it still holds its compression then you have a properly broken in piston and sleeve

Hi!

yesterday i ran my new jato (brand new) for the first time, doing the break-in steps traxxas recommends.

I can find variations of this question around the forum, but i can't find an exact answer to this question, hence why im asking (ive looked cant find any).

My question is:

how can you ever know, if you did the break-in correctly? I like to have some sort of reassurance...
Reason im asking is i had problems with the piston getting repeatedly stuck at TDC, the fit was _very_ tight. We came up with the conclusion that it was too cold outside. 55 degrees + a rather stiff wind, which made the actual feel even colder. Even after the break-in, we couldnt get it started and decided to head home and try to blow at the engine with a hair dryer. After heating it up, there was no problems. Fired up first burst of the ez-starter and idled well. No time to run anymore though so we turned it off and called it a day.

After this i havent run it yet. Its currently in my room at normal room temp. and i can still barely push the piston around with a screwdriver.
Ive run some afterrun oil through it as well to get it lubricated.

Is it still too tight? Do i have to run the break-in process once more? How can i know that i did the break-in correctly?

Thank you in advance!

[jarod_rodriguez]

I think one key to proper break-in is to be sure you don't go out for the first 5-10 tanks and just run it WOT. Varying the trottle speed and not getting it super hot etc... heat cycling the engine is good and taking it easy for a while is good. Otherwise, you run the risk of warping or cracking something and not getting a long life out of the motor. I have had all kinds of things go wrong during break-ins. Broken clutch springs, throttle servo's, mis-behaving carbs etc and I have good results as long as I just baby it for a while and get it through about 10 tanks with med-high <270 temps with varying throttle.

Just my opinions of course as I am not your warranty depot :-)

I have also burned up some motors by running it way too lean. I have sensed switched fuels that have a much higher oil contents which helps as well. I can run it fairly lean and still have a massive trail of smoke out the pipe. Almost see the oil coming out the pipe.

Good luck and happy tuning.

[kejseren]

Aight, thank you for the response!

the engine was definitely not too lean. Too rich if anything for sure. But i read its better to run abit rich during break in, but not too rich to not get the temp high enough in the engine. But i didnt fine tune it yet, ill be doing that next time im out

i guess the thing im mostly concerned about is the fact that the engine might have been a little too cool during the break-in. Im not sure though. Which is why im curious and wondering if i should do the break-in procedure once again next time im out running, or if i should just take if abit slow and not WOT it through several tanks?

[jarod_rodriguez]

Based on my experience, you can re-run the break in without any issues. You might get bored though. :-)

[slayer17]

If your break in was tool cool your fine and as jarod said you can rebreak it in. All your doing is heat cycle the piston and sleeve.

Aight, thank you for the response!

the engine was definitely not too lean. Too rich if anything for sure. But i read its better to run abit rich during break in, but not too rich to not get the temp high enough in the engine. But i didnt fine tune it yet, ill be doing that next time im out

i guess the thing im mostly concerned about is the fact that the engine might have been a little too cool during the break-in. Im not sure though. Which is why im curious and wondering if i should do the break-in procedure once again next time im out running, or if i should just take if abit slow and not WOT it through several tanks?