OS .12 CV-R rattle at idle

[mAdMan]

When disassembling and ressembling I found there to be .003 clearance between the con rod and the crank. Other then that the engine appeared to be new out of the box.

It will make the noise when standing still against my foot with the driveline stopped.

Any ideas?

[youtube]wQIU8yQB8n4[/youtube]
http://youtu.be/wQIU8yQB8n4

[limestang]

I don't think it's the engine, it sounds healthy. Are you able to check to see if something on the chassis is rattling?

Limestang

[RC10resto]

is the right side outdrive hitting the Spur gear?

[alien3t]

does it make the noise if you hit the brakes?

[mAdMan]

Im not sure it's in the chassis Limestang. It goes away completely with any throttle input and doesn't return until idle. I pulled the stock clutch and replaced it with a MIP one I drove 45 miles for...and the spring fell off on the first run...lol

Got that fixed. Got the MIP 4 in 1 all setup. I will retest tomorrow morning. It's just strange that it made the noise with the drivetrain disconnected, and with 2 different clutch systems, one being messed up.

Rc10resto I checked after reading. I have a new 64 tooth spur, pinion, now a clutch, and new rear arm mounts and all spins free with the motor off. I'll make a new video tomorrow with the MIP clutch if it's still being noisy.


Alien3t yes it makes the noise with the wheels on the ground and held still as well.



I'll recheck tomorrow and update.

[RC10th]

Could it be the pipe rattling against the chassis?

[mAdMan]

It appears it was the bellhousing/spur. I changed the clutch to the MIP 4 in 1, and did a little modification the the MIP spring. It would not hold "looped" like they wanted you to. I looped them, spun the spring, and used needle nose pliers to crimp the spring closed. Very happy with the end result.


Video I posted in the other thread of it idling.
http://www.youtube.com/watch?v=t3DUGxj2iXU
[youtube]t3DUGxj2iXU[/youtube]

[klavy69]

did you cut the flywheel pins down for the MIP 4n1?

Todd

[mAdMan]

did you cut the flywheel pins down for the MIP 4n1?

Todd

I used a old clutch bell and my flat edge vice to press the pins into the bell. Little by little while comparing the new clutch thickness to the pins. When it was right I turned on my grind wheel and took them JUST TO the back of the flywheel. Making sure to remove the same on each side and not hit the wheel itself.

Clutch is working great.

I had it rich for break in, leaned it out a little just now and the noise came back. Hmmmm

[klavy69]

leaned it out a little just now and the noise came back. Hmmmm

Glad I'm not the only one having that kind of day

Did ya ever check to see if the pipe might be hitting the chassis as suggested above?

Todd

[mAdMan]

I checked the exhaust but it's free and clear.

I think I'll pull the pinion/clutch kit and let her idle.

[RC10th]

It doesn't sound like the engine to me. Nitro engines are pretty temperamental and usually wont run if something is "wrong".

If it were my truck and you were sure it wasn't something like loose mounting bolts, pipe rubbing the chassis, gear mesh, or anything else obvious I would personally do the following. Also, while the engine is running it helps to touch or hold things to pinpoint a rattle.



Try a new glowplug first.

Remove pipe and give it a good shake to see if something foreign is inside.

Remove engine and check clutch shims for play, check for rubbing on flywheel pins or contact with the flywheel.

Check for a loose flywheel nut or one that won't tighten fully against the flywheel. (A glow plug washer is a perfect to fix this)

Check end play of crank while clutch nut is tight, does it move in and out?

Remove head and check that both head shims are installed, check the top of the piston for any signs of contact. Check the glowplug.

Remove back plate firstly making sure it was installed properly. Secondly making sure crank pin wasn't contacting it.

Remove liner and inspect for damage

Remove piston and rod and inspect for damage. Make sure/mark it so it goes in the same way. (If the rod has an oil hole it faces the crank, CV-R may have a large hole in the side of the piston but I can't remember, if so it faces the crank side)

Check front and rear bearings with and without the crank for failure, rust, play, smoothness.




If all is good reassemble and look at something else besides the engine