starting atc-90 after many years

[NJPCRX]

Ok, so my atc-90 has been sitting in a field for quite a few years. I would guess at least 10-15. Spark plug is in, and everything was left connected, so no dirt or water got in. Gas tank was drained and cap was on. Oil is full and clean. Motor turns over by hand easily. It ran when it was put away. So what do you think I should do before I try to start it up again. I'm gonna change the oil, and clean the magneto and points and check timing. Pretty much do all the checks and adjustments in the manual. I also rebuilt the carb. What else do you think I could do to get a better idea of how long it might last. Pull the head and look at the cylinder and piston maybe? I don't want to make myself sound like a dumb ass. Should I just overhaul it, or just run it till it blows up? What would you guys do? What should I look at or check?

[RDH/86200X]

Buy a spark plug as well. As of right now there is now need to pull the head. Try to start it first and see if it will run if not check your spark.

[Ghostv2]

Personally I wouldn't go so far into it. Try to get it running first and see what needs to be done from there. Remember, to check air, fuel, and spark. Try to fire it up, what could it hurt.

[jakestrawn]

U might shoot a little oil in the cylinder.....help lubricate things a bit

[kb0nly]

I second the oil in the cylinder... I usually soak the cylinder down with PB Blaster from the spark plug hole, loosely put the plug back in, let it sit overnight, pull the plug out the next day and pull it over slow a few times to loosen it up and blow out the excess PB Blaster, then change the oil to get rid of any that drained down past the rings and got into the oil, then fresh plug and fuel and let er rip, if she will.

The biggest problem from sitting that long is usually bad fuel, and condensation. If the tank was drained and its ok then your good on the fuel side, if the tank is rusty though get that cleaned out first. Cleaning the carb and checking the points is definitely a good step, but check for spark before you worry about the points.

Condensation usually ends up giving you a rusty cylinder and a bit of moisture in the oil, so even if the oil looks ok on the dipstick i would change it just to flush it out from the stuff that might have accumulated from sitting.

[NJPCRX]

Ok, my friend at work said marvel mystery oil in the spark plug hole. It has quite a bit of old oil on the bottom of the motor. It was caked with dirt and old oil around the foot pegs and shifter. So i'm worried it may have a good leak, or someone just wasn't careful when they changed oil. But its full of oil that is not too dirty? I did notice a leak around the gear shift when I removed the shifter to clean it up. Can that seal be replaced easily? I was looking around ebay and didn't find any engine rebuild kits for it? You could buy a 70cc kit cheap. What should I look up to find one, if it did end up needing rebuilt? The only thing that worries me is the magneto cover was removed while it sat. Everything looks ok, but I will have to sand the contact points. Luckily it only rains like once a year around here, and rust isnt a factor. Some idiot destroyed the wiring on the entire bike, so I bought a harness on ebay, and used coil on ebay. The 2 wires comin out of the magneto are destroyed. I'm gonna have to splice new ones in and run them through the rubber boot on top of the case. What a mess. But I am enjoying working on it.

[HondaXRider]

I always just us regular motor oil in the spark plug hole.
And there is no such thing as a GOOD leak just saying.

[kb0nly]

Check around the chain sprocket on the motor, if there is a lot of oil on the bottom of the motor someone might have punched a hole in the case with a chain slap.

[NJPCRX]

Ok, my bike still has the chain cover installed. I will look, but the oil is mostly around the base of the foot brake, gear shift, and foot pegs. I guess that is the lowest part of the motor, duh. So can you replace the seal at the base of the shifter without tearing down the gearbox?

[kb0nly]

The shifter shaft seal can be replaced by just removing the shifter from the shaft and picking it out and then sliding a new one over. Not that hard thankfully.

[NJPCRX]

I pulled the chain cover off and it is not cracked around the front sprocket. The shifter shaft has play in it. In and out. Is this bad? I think the leak is coming from one of the side covers on the motor. I still havn't removed the motor and cleaned it up. I gotta fix a crack in the frame and then paint the frame after I clean it up.