Robins 295 seized

[Steve Besmer]

I have ezgo cart with 295 Robins engine the started knocking and seized up. After taking top head apart shooting PB blaster on cilinder heads i was able to put wrench on fly wheel bolt and work back and forth and free up cylinders. Everything moves free now. Had oil but was old. Any clues what might have happen? Both cylinders move up and down together and free

[meimk]

Can't tell for sure without a teardown, but if it was knocking it was probably more connecting rods to crankshaft rather than pistons to cylinder walls. Oil pump failure, grit plugging oil passages, overheat from plugged up cooling fins? Lots of possibilities.

[slonomo]

It's common for the #2 cylinder to fail and break the connecting rod. The #2 cylinder is the one farthest from the oil pump. If the oil gets thick, dirty, old, or if there is low oil, that cylinder is usually the one that suffers first. Not always true but very common. No way to tell what the damage is until you tear down the engine for inspection.

[JPonLKN]

If both pistons are still moving up and down, Its likely you dropped a connecting rod bolt. Very typical for these to simply loosen up and back their way out over time, usually results in a broken rod, but its possible yours simply didn't break yet, but if that is the case, the rod would still be shot. Crank will likely be salvageable. The other possibility is loss of oil pressure to the rod or bearing journals...one of those passages gets blocked with debris, and the bearing surfaces won't last long. Usually, it will just slow and sieze, without knocking too much though. My bet is a loose con rod bolt. You can pull the oil filter out and possibly see the bottom of the con rods with the engine still in the cart.

[CP241]

Freeing it up is a good thing.

But if it were me, my next step would be tearing the engine down and finding the root cause of failure. Paying particular attention to the crankshaft for galling. There’s no bearings between rod and crank, so when oil goes low or something happens with lubrication the aluminum rods will gall up and leave some behind on the crankshaft. You can polish it with Emory cloth to remove it.

Also pay close attention to the oil pump for scratches and wear. And you didn’t mention what year the cart is, but if it’s a mci motor inspect the timing belt side of the head where the crankshaft rides very closely for wear. Those have a tendency to seize. The pre-mci are much better about it. If you look at the exhaust, the pre-mci has a cast exhaust manifold bolted to the head, and the muffler bolts to the manifold. On the mci motors the muffler bolts directly to the aluminum head.

Either way I wouldn’t run it without tearing it down and finding out what failed and why. It’s probably salvageable now but if you run the engine just because it’s freed up, it may cause it to fail much more catastrophically

[crash12888]

Originally Posted by CP241

Freeing it up is a good thing.

But if it were me, my next step would be tearing the engine down and finding the root cause of failure. Paying particular attention to the crankshaft for galling. There’s no bearings between rod and crank, so when oil goes low or something happens with lubrication the aluminum rods will gall up and leave some behind on the crankshaft. You can polish it with Emory cloth to remove it.

Also pay close attention to the oil pump for scratches and wear. And you didn’t mention what year the cart is, but if it’s a mci motor inspect the timing belt side of the head where the crankshaft rides very closely for wear. Those have a tendency to seize. The pre-mci are much better about it. If you look at the exhaust, the pre-mci has a cast exhaust manifold bolted to the head, and the muffler bolts to the manifold. On the mci motors the muffler bolts directly to the aluminum head.

Either way I wouldn’t run it without tearing it down and finding out what failed and why. It’s probably salvageable now but if you run the engine just because it’s freed up, it may cause it to fail much more catastrophically

Not may, It will!!! save it now with just a rebuild kit,
295 complete kits on ebay for $288.00

[Steve Besmer]

Originally Posted by slonomo

It's common for the #2 cylinder to fail and break the connecting rod. The #2 cylinder is the one farthest from the oil pump. If the oil gets thick, dirty, old, or if there is low oil, that cylinder is usually the one that suffers first. Not always true but very common. No way to tell what the damage is until you tear down the engine for inspection.

I will keep digging into and will update what I find. Thank for all replies.

[Steve Besmer]

Originally Posted by Steve Besmer

I have ezgo cart with 295 Robins engine the started knocking and seized up. After taking top head apart shooting PB blaster on cilinder heads i was able to put wrench on fly wheel bolt and work back and forth and free up cylinders. Everything moves free now. Had oil but was old. Any clues what might have happen? Both cylinders move up and down together and free

tore apart and cylinders and rings look good. 1 connecting rod was only finger tight. Everything else looks good and clean.

[slonomo]

Originally Posted by JPonLKN

If both pistons are still moving up and down, Its likely you dropped a connecting rod bolt.........My bet is a loose con rod bolt. You can pull the oil filter out and possibly see the bottom of the con rods with the engine still in the cart.

You called it!

Now the question is....to rebuild or not to rebuild?

[CP241]

Originally Posted by Steve Besmer

tore apart and cylinders and rings look good. 1 connecting rod was only finger tight. Everything else looks good and clean.

I can’t count how many of those I’ve found just like that.

I’d just tighten it up and see what you’ve got. Most the time that can cause them to bind, and they’ll run just fine once you torque them down.

No idea why they loosen themselves up but I’ve had several carts do exactly that.