New Member - Dan Stoner - Cub 102

[cubs4lifeofme]

Welcome from your N.Y. neighbor Dan. Good luck with the 102

 

[Dan Stoner]

My optimism of getting my 102 running has turned to disappointment. Today I took the spark plug out and hand turned the flywheel, watching for the piston to move. It didn't! I'm not sure how much movement there normally is, but I didn't see any movement. I did hear some movement from within, like movement of the rod but I can't be sure. I guess I'm now looking at taking the engine out. I'm going to need advice on how to go about this. I also have no idea where to take the engine for repairs. My skills are limited. I'm located in central Pa., not sure where to turn.

 

[Ken farmer52]

Stick a long wooden dowel rod in the spark hole. See if it moves up and down. Or shine a flashlight in the hole and watch for movement.

 

[Dan Stoner]

Stick a long wooden dowel rod in the spark hole. See if it moves up and down. Or shine a flashlight in the hole and watch for movement.

I did that. I didn't have any movement.

 

[lpalma]

The spark plug hole is not over the piston, it is over the valve area, pull the head, gotta clean the carbon anyway...

 

[Dan Stoner]

OMG...thank you. I was ready to give up on this thing. I'll post a picture once I get it. Won't be for another week or so. Can't work on it every day.
Thanks again.

 

[jkoenig]

Who says you can't work on them everyday?

 

[mgwin]

Take the muffler off, put your hand over the hole and turn the crank. You should be able to feel some compression.
If you just want to get it running, work on getting fire to the plug first. Then work on getting gas to the plug. That should start it.
Once you get it running, then you can do other things to it. Like cleaning the carbon as Lewis said (requires new head gasket), new plug, new plug wire, new fuel filter, rebuild the carb., etc. Just depends on how much you want to spend on it.

 

[cub1961]

in my somewhat limited experience i have found the ignition switch to be the culprit a few times. at least 3 that i can think of. it is easy enough to check. if you don't have 12v at the + side of the coil with the key on then check the connections inside the dash. you can rig in a toggle switch in place of the ignition switch to get by until you get the old one working or replaced.

theres a lot of info on youtube for troubleshooting the spark in these things. the wiring is actually very simple. there are good wiring diagrams on this site as well. almost all of the ones i have bought have butchered wiring harnesses as well. this can lead to a lot of problems. its a good idea to pull all the connections one at a time and clean or reterminate them. if the harness is a real mess you can buy a new one for around 100 bucks or make one yourself.

 

[Dan Stoner]

The spark plug hole is not over the piston, it is over the valve area, pull the head, gotta clean the carbon anyway...View attachment 152921

What should I use to loosen the carbon deposits?

 

[1811Cub]

What should I use to loosen the carbon deposits?

I use easy-off oven cleaner, and a brass cleaning brush. Make sure you are very careful when cleaning the top of the piston. Make sure you don't leave carbon between the top of the piston, and the bore. Heavy carbon deposits can scratch the bore or piston. Cleanliness is next to godliness.

 

[Dan Stoner]

I use easy-off oven cleaner, and a brass cleaning brush. Make sure you are very careful when cleaning the top of the piston. Make sure you don't leave carbon between the top of the piston, and the bore. Heavy carbon deposits can scratch the bore or piston. Cleanliness is next to godliness.

When reassembling the head, is it important to put the bolts back in the same holes? I was planning on making a template of the head gasket to organize the bolts until I reassemble.

 

[1811Cub]

Yes, I would. Also, run a die down the bolt threads, and a tap in the block to ensure accurate torque readings. Also, the torques sequence is as important as the actual torque spec. A lot of guys check the head for flatness while it is off to ensure sealing.

 

[Dan Stoner]

When reassembling the head, is it important to put the bolts back in the same holes? I was planning on making a template of the head gasket to organize the bolts until I reassemble.

Should I use anti-seize on the threads?

 

[1811Cub]

I would not. I use only new engine oil. Coat the threads in oil, then torque initially at 15 ft-lbs, then go back and retorque to 30 ft-lbs.

 

[jkoenig]

Should I use anti-seize on the threads?

Here we go:


Sorry Dan. You had no way of knowing, but this has been a topic of discussion a few times.

 

[mgonitzke]

It won't matter if the bolts go back in the same holes. If it did, there would be something in the manual about it. They all need to be clean and in good condition, but of course any studs and/or different length bolts need to go back where they came from.

Anti-seize is fine on the threads. I have used it for many years with no issues. This is an application that product is meant for. Don't forget to retorque the head (after the engine cools) after the first 30 minutes of run time.

 

[Dan Stoner]

I've found aftermarket carb's on ebay that say they fit my K241AS engine. Anyone have experience with using them. My original is in bad shape.

 

[mgonitzke]

They are a crap shoot. If you get a good one, it will work. If you get a bad one, it will never run right. The quality is worse than the original carbs regardless. What is wrong with your current one? Isn't much that cannot be fixed. I would get a good used carb to rebuild before rolling the dice on an aftermarket one.

 

[Dan Stoner]

They are a crap shoot. If you get a good one, it will work. If you get a bad one, it will never run right. The quality is worse than the original carbs regardless. What is wrong with your current one? Isn't much that cannot be fixed. I would get a good used carb to rebuild before rolling the dice on an aftermarket one.

I'm a rookie at this. I know nothing about rebuilding a carb. Original carb is really gummed up. It has sat for 30+ years. Local Cub dealer wants $100 to rebuild it. I just replaced the key switch and I now have power to starter. With carb off, I got it to fire by using starting fluid. Now I need a working carb to get it running.