Engine locked up on the highway

[1983lux]

Hi all,

Was driving the bike down the highway, when suddenly there was a noise, a puff of smoke, and the engine quickly lost power and stalled. The starter would try, but couldn’t turn over the engine. Checked timing belts under the cover and they had not broken. Oil level was okay. Got it towed to a repair shop nearby and will have to trailer it home.

Very similar to an incident 5 years ago where I had taken a bolt out of the cam holder in the head, trying to remove a broken valve cover bolt. Because the cam was under tension from the belt, it wore a groove in the cam bearing and locked the engine up, bent a couple valves. I had some 79 heads so put my 75 cams (damaged one cleaned up at engine shop before install, was harder than aluminum head so not much damage) in them, changed my belts and it worked fine for last 5 years.

Anyway, I suspect something similar has happened but it’ll probably need some dissassembly once I get it home to figure out what happened.

[1983lux]

Historical post from last time something like this happened:

http://ngwclub.com/forum/viewtopic.php? ... 85fee87236

[Fred Camper]

My first step would be to see if it will turn over with a wrench. If not, remove the plugs and see if it will turn over. Could be something like a head gasket that let coolant into the cylinder and taking the plugs out will rule that out.

[1983lux]

Oh wow, but would a blown head gasket really be enough to lock up a running motor instantly?

[Fred Camper]

Coolant in the cylinder certainly can lock things up quick. The white puff is a witness mark.

[CYBORG]

And a bent rod is another one

[redglbx]

Yepper , coolant in the cylinder can definitely lock things up and bend a rod, coolant doesn’t compress. As Fred said above pull the plugs & turn it over by hand. Be prepared as you this can shoot a stream of coolant from the plug holes across the room easily, so be prepared for that. Protect yourself.

If you have coolant in the cylinders you’ll have to pull the heads and then check for how far below the top of the cylinders the pistons are at TDC and that should tell you if a rod is bent. They should be pretty close.

If you have a bent rod you have a couple of choices, pull the motor apart and change out the bent rod,

Or just put fresh head gaskets in it and just run it until it completely fails (not recommended) , but the gl motors are surprisingly resilient and durable, it may last a while.

Or just find a junkyard motor and just put it in and run it forever & enjoy it, that’s what I’d do !

[1983lux]

Well, I got it home and had a bit of time to look at it. #3 plug was suspiciously hard to remove, and the end of it looked like this maybe a valve broke off?

IMG_5100.jpeg

[redglbx]

Ohhhh, that is just ugly ,,, guess it’s time to look for a replacement engine. It would be interesting to pull the head just to see what happened but that’s just me being free with your time. Sorry !

[Whiskerfish]

[Whiskerfish]

another one bites the dust.gif

[Fred Camper]

Yep, my bet, with no dollars, is you will find a head gasket issue that allowed coolant into the cylinder and that broke a valve as it tried to open. It is shopping time. I have a spare but you are too far away.

[1983lux]

Ouch!!

I’m guessing those scratches on the cylinder wall means it’s not doable to just replace the piston. GL1000 engines are not easy to come by up here in Canada. Maybe a GL1100 or 85-87 GL1200 might be easier to find. I do have a spare head if I were to run 1000 heads on either of the later blocks, but I read there’s issues with them being overly low geared with the 1000’s drive system. Probably worth a separate topic post though.

[ritalz]

Dang, that looks pretty nasty. I would be looking for another motor.

[redglbx]

Lux, so sorry for your trouble there but I wouldn’t spend anytime on that one unless you really need something to hold a stack of paper down.

An 1100 motor would be a relatively easy fit, that’s what I would do, the gearing is a little shorter than the stock 1000 I believe, I had a 78 with a 80 1100 motor and it did spin a little faster (couple hundred more rpm) but wasn’t really noticeable, it did have 75-77 1000 heads and cams and it definitely wasn’t lacking for giddy-up. Let us know how it goes.