dgrahm225,

The motor may be detonating, It sounds like you may need to add a head shim. Try adding .004 and see how the plug looks.

Jim

Pull off the head and see how many shims it has or measure them. Stock has 2 aluminum 0.30mm shims with a 0.10mm copper shim in between equaling 0.70mm. If it has 4 gallons on it, it need have low compression. You can usually get them to run, but it will only hold idle for 10-15 seconds unless you keep revving it. The stock glowplug to use is a Novarossi #6, in standard or turbo depending on the installed head button. The O'Donnell's 99 glowplug is another option. Being it is used, make sure it does have good compression though, as you will be chasing your tail trying to tune a worn out engine. Weak compression will eat glowplugs and so will a leaky front bearing or case air leaks.

Hi everyone. I need some advise. I think there is something wrong with my engine (Rex Re-12S3). I have not run my touring car for slightly over a month. The last time i ran it , it was okay, i think. But during the final laps, the car wasn't picking up speed. In fact it was moving then slows down, moving then slows down when i rev up the engine. I was told at that time the engine could be overheated. 1 month+ later ie yeaterday, when i played the car again the engine cuts off upon acceleration. I lean the HSN & low end needle, it doesn't help. What could be wrong? Not been playing for a long time? Time to change the conrod? Change the bearing or something else? Please help me:cry:. Thank you.

thanks guys, i appreciate the help! as soon as i can get it torn down to check it out, ill post back what it was!

How old is the motor? It could be tuning only. Check for smoke and make sure you are making a trail of smoke. If it has been overheated, chances are the glow plug might not be good anymore so change to a new one.

Did you just put the car away or did you put some kind of oil in the motor for the month it sat. If it sat in a humid place and rusted, it way be harder to get going and may need maintenance. I would change the plug and try to richen the motor. Especially if it was lean at the last race. Go 1/2 turn on the bottom and 1/4 turn on top. try to start with this and see if it helps.

DJ Apolaro

Hey fellow r/c drivers, thanks for the advise. The engine is 3 months old. It seems that the glow plug could be the cause. Oh DJ Apolaro, when you mention 1/2 turn bottom, 1/4 turn top you mean clockwise or counter- clockwise? Yeah, I hardly see any smoke. If the engine is overheated, other than the glow plug, what kind of damage can be inflicted on the engine; permanent? BTW how do i know it is the time to change conrod or bearing? So far i have never disassembled an engine. Is there any website that offers such advice?

Counter clockwise to make it richer, Sorry I forgot to say which way. The bearing will either start to leak (more than normal) or you can actually hear the bearing going bad. over heating an engine can cuase many bad things. It will loose it pinch. As far as changing a conrod, you can do general maintenance every ? hours or I notice that when the engine stops holding an idle it has a lot do to with the conrod going bad. Not that this is the only thing, but it is one way. If you have a used motor from someone, I would change it to be safe. If the motor has good pinch and everything else looks normal than I would change the rod.

Hope this helps,

DJ Apolaro

ok, i havent gotten the whole motor out of the car due to a f@#$@ stripped screw and didnt have time to fight with it, but i did remove the button to check it out, its pretty f'd up if you ask me. check out the pic. and yes, im assuming stock shims--two aluminum and 1 copper sandwiched in the middle.

http://i43.photobucket.com/albums/e3...5/DSCN0091.jpg

That button looks F'up for real. Not sure, but it looks like water damage. I can't tell if thats detonation pits from the color in the pic. What does the piston top and sleeve look like? If your trying to get the back cover off, make sure you rotate the piston to TDC or close to it. The piston skirt will break off, if you try to force the back plate off with the piston at BDC. Feel if there is any resistance when you rotate the crank. A sleeve with good pinch will usually push the sleeve out of case or the piston will get stuck as it gets closer to TDC.

yea, the piston top and button look pretty f'd up... the button doesnt looks so much like pits, but actually bur-like? its crazy? but heres a pic of the piston top, it makes the sleeve look bad also, but its not as bad as the pic makes it look... but i dont know what to do with this thing, i havent gotten it to run right since i bought it. i guess thats what i get for buying a used motor from someone i dont know, hahaha!

http://i43.photobucket.com/albums/e3...5/DSCN0095.jpg

I have no clue what the engine was running on or what happen, but it should be smooth inside the button and piston top withg a dark chocolate to light brown honey tint it its running fine and tuned correctly. Any pitting or roughness is inproper running/maintainence or over heating.

yea, i know what you mean, thats the first time ive removed the head and now i see what the motors been through. do you think its salvageable at all? i may order a new motor and keep this one for a last resort spare, LOL! any suggestions guys? :confused::ha:

It is hard to say what the problem is and being a used motor makes it even harder. You most likely will need a new piston and sleeve and may want to change the conrod, since it was used. What fuel do you run (% and brand)? Make sure for the next one that the motor is shimmed correctly. If the motor calls for .5 go .55 if .6 go .65 and so on. This will help you bring in the motors tune slower and ensure that you do not have this problem again. Just till you have an understanding of how the motor work. This will save you $$$$ in the end.

Regards,

DJ Apolaro

i use sidewinder 30%, but ive only run 1/2 gal on this motor since i bought it, never could get it to hold a tune. ive struggled with it for quite a while, im about to cut my losses and buy a NEW motor and start over..

i can drive the wheels off it, but being new to nitro, i cant readily identify alot the problems, etc. i know enough and have had help along the way to get some runtime with it, but with no luck keeping it consistant, so it was a learning experience to say the least, haha!