• Welcome to RCTalk! 🚀

    Join the #1 RC community where hobbyists connect, share, and get expert advice on RC cars, trucks, boats, drones, and more!

    • ✓ Friendly & passionate RC enthusiasts
    • ✓ RC tips & troubleshooting
    • ✓ Buy, sell & trade RC gear
    • ✓ Share builds & upgrades

ahh what caused this to happen?

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
C

cooldude

RCTalk Racer
Messages
104
Reaction score
0
Points
0
RC Driving Style
ok engine was running good then it died so i try to fire it back up then it wouldnt start..i felt it was not spining good so i stop it so i open it up then i saw this..its like the part of the button head had a little chunk that came off
and got in the piston and messed up my piston and sleve..now there like a metal piece that like stuck on the piston that came off the head button..
i was running with 20% odonals and the engine was running around 180 to 210
it was still getting warm just started it too..i always blow off dust before i replace the plug or check it..
DSC06940.webp

what caused this to happen?:doh:

thanks
 
Last edited:
It's hard to see, but looks like you had a serious detonation problem. This is normally due to having too high of nitro, too few head shims and too hot of a plug. Causes the fuel to explode when the timing is wrong.
 
its been only on 1 gallon and quater..yeah the pic is not that great its from my iphone ill fix it with better pix quality
 
alpinehyperlite said:
Or, it could just be worn out from time.
Click to expand...

I wonder how much time it would take for an engine too look like that if properly cared for? I have 15+ gallons on an engine of mine and it has a little bit of pitting on the button, but nothing serious.

Although, if you lost your pinch and it was running poorly/not holding a tune, then the compression stroke was letting a lot of force by the piston, which would tend to make you lean it out to get performance out of it, which would in turn burn it up more quickly... That in mind though, I've had many engines and never had pitting like that.

I did have a main bearing split a ball in half on me on a 4 gallon old engine. Of course, that piece of bearing went through the engine like a grenade and just sliced up the piston...
2007-0224-OS21RGBearingBrokePistonGouge.jpg
 
so in this case i have to buy a new piston and sleve and button head and rebreak in again and shim..i couldnt get the button from the sleve to come off so i had to get a flat head to pier it open and i broke the shims but they dont cost much thoe..but yeah I'm bum about this..its been only on 1 gal and couple of tanks then this..ahhh grrr:angry: time to stay for some overtime at work:\
well its part of learning and hobby so yeah i know what i was in for anyways..fix the pic now looks more better

but yeah thanks everyone for the explainations..

now what could i do to prevent this from happening again? i do run plugs thats suites for my weather and i only run 20% nothing higher i do tune to conditions..advice are welcome

thanks:D
 
Just make sure you properly break it in, and care for it properly after running, plug exhaust and carb when not running to keep out moisture.
 
alpinehyperlite said:
Just make sure you properly break it in, and care for it properly after running, plug exhaust and carb when not running to keep out moisture.
Click to expand...

thanks will do ..do you think my rod will still be ok to use? it does have a minor scracht on it but nothing major

thanks
 
You could, but if it were me, i would just do a complete rebuild while its broken down already. If you go cheap with your stuff, it will preform cheaply. Parts usually dont wear equally, so if you put a brand new part in with old, possibly damaged parts, you could damage the new parts.

Say your rod has 2 tanks left on it, and your piston and sleeve are brand new. If the rod breaks in two tanks, then it will break, and cause the piston to damage the piston and sleeve, thus your brand new piston and sleeve has only lasted you two tanks. See what i mean? Thats just how i see it.
 
If it were me... I'd buy a new engine and keep this one for spare parts. The carb, head and crankshaft are still good. Without taking the engine completely apart, take out the bearings and wash the entire thing, you can't be certain there isn't a renegade hunk of aluminum still in there that will tear up your new piston/sleeve.

Even then, you had issues with this engine, so there may be a manufacturing defect in the crank case somewhere or something. The damage you did to the button may also be on the crank case where you did the prying.

I'd inspect the rest of the engine very carefully because I doubt that piece came off the button but rather got sandwiched between the button and top of the piston.

End result, this one is parts, save up for a new one. Just curious... what engine is this? I don't see a mfr or model quoted anywhere.
 
Last edited:
Oh... well, then maybe I'd rebuild it, but probably not. Too many unanswered questions with it to bother trying to "fix" it.

Did you figure out where the hunk of stuff came from yet? Or does it appear to be only the head button/piston top are the likely sources? Just seems odd that a chunk of the head button would fall out... I mean, it's a machined piece of aluminum. I could see it being a bit of the piston skirt breaking off, or a piece of a bearing or something.
 
olds97_lss said:
Oh... well, then maybe I'd rebuild it, but probably not. Too many unanswered questions with it to bother trying to "fix" it.

Did you figure out where the hunk of stuff came from yet? Or does it appear to be only the head button/piston top are the likely sources? Just seems odd that a chunk of the head button would fall out... I mean, it's a machined piece of aluminum. I could see it being a bit of the piston skirt breaking off, or a piece of a bearing or something.
Click to expand...

ahhh i did remember a leak of fuel by the fly wheel and gears were it was coming off the bearing i checked it and it spins fine i tot i flood the engine so i just spay it down with some cleaners..ill check the bearings ..but for now its in pieces put away for now. i did spray it with WD40 down before i store it just so it wont have rust..
 
Not sure if you caught the photo of my damaged piston. YOu can see nicks in the con-rod and the inside of the crank case had nicks and cuts all over in it just from half of one of the ball bearings in the rear main bearing. It took me a while to find the cause, but once I did, I felt better knowing it wasn't something I did.

I didn't notice it at first because I was seeing the side of the ball that was still there. I spun the bearing around slowly with my finger and saw the busted ball. It's the weird spot in the bearing race on the left side of the photo:
2007-0224-OS21RGBearingBrokeBearing01.jpg


It's amazing all it takes to destroy one of these engines. Especially when you consider the punishment we put them through!
 
did you check the plug to see if the coils were still intact? they could have fell out of the plug and caused the damage.

could have been something that got in the exhaust pipe and was sucked back in the engine.

something may have been in the head around the plug hole and you accidently knocked it in the engine when changing the plug.

I'm with olds, something made its way into the combustion chamber and took the chunk out of the button and piston.

you can polish the rod if its only got a scratch(its a performance mod anyway), while its apart i would remove the crank to clean and inspect everything else before just slapping a new piston/sleeve in it.
 
plug coil was still good nothing deform or anything..

ill look into my bearings if it broke off or somthing..but still spins smooth thoe but there was leak so has to be bearings ill look at it and take pics of it..

what would cause a bearing to break like that? high temps or just from use from running it also with vibrations ?
i dont run hot just around 230 to 250

thanks
 
That looks a lot like a glow plug failure. The element dropped into the engine. Was this the original plug in the engine, or had you changed it since break-in?
This is why I always throw away my break-in glow plug after 5 tanks of fuel. Break-in is rough on the plug element.
Edit; just saw you posted right before me.
Is the piston wrist pins still in place?
I'd send it to RB, way too much dough for a one gallon failure!
 
If you look at the picture you can see the hole in the button head that matches up with the piece on the piston. I use to work a Aluminum Company called Alcoa in there cast house. From my experience it looks like you might have had what we refer to as a inclusion in the button head, which caused the chunk to come out. I would contact RB send the parts to them. Looks alot like a manufacture defect.
 
GrudgE said:
If you look at the picture you can see the hole in the button head that matches up with the piece on the piston. I use to work a Aluminum Company called Alcoa in there cast house. From my experience it looks like you might have had what we refer to as a inclusion in the button head, which caused the chunk to come out. I would contact RB send the parts to them. Looks alot like a manufacture defect.
Click to expand...

yeah when i put them together it fit like a glove and my bearing are good..ite a perfect match too..ill take pic of it tommorow see what you guys think..
 

Similar threads

mambro401
What does everyone recommend??
Replies
13
Views
734
mambro401
mambro401

RC Builds

Back
Top