6.5 Honda Clone Randomly Seized up?

[stubone278]

Hi yall,

I've read and learned tons from this site, but couldn't find this issue so I decided to make my first post.

I've got an old thunderkart with a 6.5 Clone. It ran perfectly fine until the throttle cable broke off at the engine. I shut the engine down (due to the cable being broken). So the pedal doesn't work, I figured I would just push the throttle manually so I could make my way back to the shed and fix it. When I went to start it back up again, CLUNK. The thing wouldn't turn over.

I took out the spark plug and was able to push the piston back down with a dowel, but upon pulling the rope it just goes to compress and gets jammed.

I haven't been able to break it down yet, but what are yall's thoughts? Symptomatic of a stuck valve?

 

[Doc Sprocket]

That's an odd one, eh? Could be coincidental to you shutting down. Drain the oil and take the side cover off. I wonder if you broke your rod...

 

[KartFab]

Could be a lot of things... I couldn't figure out why one junky small engine was seized... Turns out the flywheel was catching on the magneto.

 

[Doc Sprocket]

No doubt. I've seen a lot of oddball stuff like that. It could very well be a dropped valve, or the flywheel striking something. Heck- the governor could have grenaded, an the crank is striking the arm. Only tearing into it will tell.

 

[stubone278]

Thanks for the replies! I may be able to look at it this weekend, I'll report back what I find.

 

[stubone278]

Update

Well this project got put off for quite some time! Well I figured it out today (and decided to junk the motor). So it wouldn't turn over all the way so I pulled the crankcase cover and everything looked fine. Upon putting it back on, I put one of the alignment pins in the wrong place! (When I looked back there were actually 3 holes to put pins in but only 2 pins, so I just assumed where it went was correct) It was too late when I hit it with the drill it cracked the crankcase cover instantly.
I still wanted to know why it wasn't turning all the way over so I started to take the cylinder head cover off to see if part of a valve broke off or something. While I was looking over the motor, I saw a bolt in a place it wasn't supposed to be...... stuck on the magnet of the flywheel

You can see in the picture, the bolt fell off the gokart frame and into the small hole where it locked up the motor.

Such a shame that a simple problem led to the motor being junked. Still lots of good parts so I'll save them for another time.

Only real good news is I have an old Honda 5.0 that I'm gonna now put on it, so it's not all over for the kart.

 

[B.M.800]

Where is it cracked at?

I hit it with the drill

Not sure if using a drill is really the best thing to use.
?

 

[Doc Sprocket]

I can think of no good reason to use a drill anywhere near an engine under normal conditions. What exactly were you doing with a drill?

 

[buckwheat]

New side covers should be available from a number of venders if I recall correctly.

 

[stubone278]

I was being lazy and had a drill with a socket on the end.

 

[B.M.800]

^^ I knew it! I know what you mean, putting bolts in or out can be a pain if you only have a wrench.
Im looking to get a bunch of ratchets and sockets gathered up, they make life easier... but not too easy.

Like buckwheat said, you should be able to find a side cover somewhere.

 

[jandj]

Check the for sale & clone pages at Bobs 4 cycle site. Lot of racers have stock parts they replaced laying around. IIRC Dover Powersports also sells stock parts they removed when they build race clones.
You can also post on just about any kart site, odds are somebody will have one they don't need.