Engine decides to lock up on me. Help!
 

http://www.youtube.com/watch?v=ETs36ME5R-A

Video is pretty self explanatory. The piston locks when its at the top of the sleeve. I also found crap in the engine and don't know how it got there.

The piston is supposed to be tight at the top. Not sure if you have any other problems. Invest in a clutch shoe removal tool and have your local hobbyshop show you how to take the clutch apart.

Rex

Its not just "tight", it clicks and locks. While it's locked (like shown in the video), it can wiggle a little, it has some play. This is the third engine I've owned. This is not normal.

My engine used to do the same thing, but today it stopped doing that. :confused:

You could send it to me I do engine service.

Rex

I'll consider it. What do you charge?

I think you'll find that you damaged the piston. Many competition engines will stick the piston a little at TDC when they're brand new, but the only way an engine gets tighter after you've run it is for debris to get stuck between the piston and sleeve. My guess is that you've lost one of the retainer clips for the wrist pin, or maybe you lost pieces of the rear bearing and it scored the piston skirt. This makes the piston really tight in the sleeve. Look for a bright/polished vertical stripe in the surface of the sleeve and you'll know where the piston is damaged.

To get the engine fully disassembled, put a couple zip-ties through the exhaust port and rotate the crank to move the piston upward. You're probably going to have to use pliers on the flywheel because the sleeve is probably really tight in the block. The use of the zip-ties should get the sleeve to pop up just a little bit, which should give you enough to work it the rest of the way out by hand.

Regarding the carb - don't worry about the lower screw. It's a hole where you can install a boost bottle, but those were debunked years ago as not improving performance at all. I'm not quite sure why they would include that feature in a new engine so many years after, but maybe the engine is THAT old. Re-install the screw that you took out of the carb clinch nut Tighten it all the way back down and, just as the screw starts to tighten up, back it off three turns, but don't remove it completely. Whack the screw head with a screwdriver handle or something that's not going to damage the screw head. This will force opposite half of the clich nut out of the bore and loosen the grasp on the carb. Now, remove the screw, thread it in from the other side and now you have something to grasp and remove that half of the clinch nut. Once that half is removed, use a 2mm allen wrench to poke the other half of the clinch nut out of the engine block. It might take some persuasion, but once both halves are removed, the car will come out easily. As a side note, you don't need to remove the clinch nut to separate the carb from the engine block, but yours sounds like it's stuck so complete removal and a good cleaning might be in order.

There are some clutch removal tools that might be helpful, but if the clutch is worn, then just rip them off and don't be concerned about damage because they're being replaced anyway.

I'm willing to bet that you need at least a new piston and sleeve, if not a crankshaft bearing or two. Make your own decision about the cost of the piston and sleeve, but if you need any bearings, it's going to cost more than replacing the engine.

Good luck.

This really feels more like a bearing problem. The engine doesn't have any more pinch than it used to, it just locks when the piston is at the top. It clicks, like it's locking into place. Its very hard to describe

take it to a local who knows their stuff...or Send it to Rex....he'll figure it out. :nod:

The problem may have been caused by a bearing failure, but I can assure you that the piston is damaged. That's free of charge. ;) Bearing debris or a wrist pin retainer have scored the piston skirt, which is why it's so tight at the top of the bore. I've seen it many times.

Ok i just watched the video....that motor is pooched from what i can tell.

If you dont know how to remove a 3 shoe clutch you need to get out the manual and get reading. :nod:

I would honestly like to, but the reason I don't know much about this engine is because it didn't come with a manual, and I've searched everywhere on the internet for one with no luck.

I charge $35.00 to rebuld a motor, all parts are extra. Includes pinching the sleeve, cleaning, inspection and any parts replacement. Also includes shipping back to Us. If it is not fixable then I only charge return shipping.

Rex

Thanks rex, I'll think about it. I'm deciding whether to get my engine fixed or to sell everything and buy an E-Revo VXL or something.

Your going from a 1/8 nitro buggy to a 1/16 mini electric Traxxas? :rolleyes: