So... I bought a Hawk off Craigslist

[letsride]

Originally Posted by Ariel Red Hunter

The old fashioned way to do a compression test was to wedge the throttle wide open, jam your thumb into the spark plug hole, and crank the engine. If it has got decent compression, you won't be able to hold your thumb in or on the hole.

YEP!! and the old fashioned way to check spark is what my Dad did, " Here son, hold this here wire for a second' He was only able to ever check spark that way ONCE, after that he had to find some other kid.

[ben2go]

Originally Posted by Ariel Red Hunter

The old fashioned way to do a compression test was to wedge the throttle wide open, jam your thumb into the spark plug hole, and crank the engine. If it has got decent compression, you won't be able to hold your thumb in or on the hole.

I tried that on my wife. She didn't like it and I promptly picked myself up off the floor.

[mdyates]

Finally did compression test and needle didn't move... Check out this video of smoke coming out of crankcase while trying to start. Any guesses before i tear down?

[2LZ]

Man....someone did somethng brutal to it...like run it with no oil or something. These CG motors are as sturday as the day is long.
Fortunately, they're super easy to tear down. You should have the head and cylinder off in no time. I'm not sure if it's just rings. Look for a holed piston. That's a ton of smoke.

[JerryHawk250]

I'm visualizing a hole on the top of the piston. Doesn't look good. Hope your lucky and it's not as bad as it looks.

[Customx253]

Classic! My dad got my on that as well. Only worked once though.

[Ariel Red Hunter]

Originally Posted by mdyates

Finally did compression test and needle didn't move... Check out this video of smoke coming out of crankcase while trying to start. Any guesses before i tear down?

Yeah, you tried the MarvelMysteryOil routine for two days, and it didn't work, right?

[mdyates]

Originally Posted by Ariel Red Hunter

Yeah, you tried the MarvelMysteryOil routine for two days, and it didn't work, right?

Yes, but really only a day long.. Tonight ill pull head off atleast to inspect. Is there a manual somewhere on the net?

[Ariel Red Hunter]

Originally Posted by mdyates

Yes, but really only a day long.. Tonight ill pull head off atleast to inspect. Is there a manual somewhere on the net?

OK, if you are going to pull the head, pay attention to this warning. Make absolutly SURE that you mark the pushrods with a sharpie or something. I use "X" for exhaust, and I for intake. You don't want to get those two mixed up. Engine break in makes each of the component parts (Lifter, push rod, rocker arm) married to each other. For life. Other than that, pulling off the cylinder head is no big deal. Tell us what you find when you take the head off. If nothing looks wrong, gently pull the barrel off. As soon as you lift the barrel 2 inches or so, stuff a clean,many times washed towel or leg of an old pair of 'jeans into the top of the crank case. If you do this right, the piston won't hit any thing when you pull the barrel off of the piston. Now, look for broken rings, and seizure marks on the thrust side of the piston. I had one case where the engine seized just enough for the piston to nip the rings.


At that time and place, new pistons were un-obtainable for that engine. So I carefully removed the rings from the pistons, and using a jewelers file, carefully restored the ring lands, and smoothed off the seizure marks on the thrust side of the pistons (it was a 500cc twin). I put it carefully back together, and the owner rode it for years afterward with no complaints to me......ARH

[ben2go]

It sounds like to me that the valves are hung open and possibly the rings are stuck. I've seen a crankcase vent like that from a lot of moister in the air and heavy use of the starter to spin the engine.

Good luck.

[letsride]

You know a video series of the tear down and rebuild would make you a VERY popular man round here! just sayin

[bogieboy]

Originally Posted by Ariel Red Hunter

OK, if you are going to pull the head, pay attention to this warning. Make absolutly SURE that you mark the pushrods with a sharpie or something. I use "X" for exhaust, and I for intake. You don't want to get those two mixed up. Engine break in makes each of the component parts (Lifter, push rod, rocker arm) married to each other. For life. Other than that, pulling off the cylinder head is no big deal. Tell us what you find when you take the head off. If nothing looks wrong, gently pull the barrel off. As soon as you lift the barrel 2 inches or so, stuff a clean,many times washed towel or leg of an old pair of 'jeans into the top of the crank case. If you do this right, the piston won't hit any thing when you pull the barrel off of the piston. Now, look for broken rings, and seizure marks on the thrust side of the piston. I had one case where the engine seized just enough for the piston to nip the rings.


At that time and place, new pistons were un-obtainable for that engine. So I carefully removed the rings from the pistons, and using a jewelers file, carefully restored the ring lands, and smoothed off the seizure marks on the thrust side of the pistons (it was a 500cc twin). I put it carefully back together, and the owner rode it for years afterward with no complaints to me......ARH

wow... way more attention to detail than i ever put into a teardown... and i am a trade mechanic...LOL if it can take the force of several thousand explosions per minute, its not a fragile little flower...LOL never heard of needing to mark the pushrods... niether honda nor John deere spec needing to take care to make sure the pushrods go in the same spots...

its a CG... tear it down, throw some parts in it and go.... not like a ferrari engine...LOL

[Azhule]

How much does a set of new "chop sticks" (aka "push-rods") cost anyways? It's under a fiver I'm sure

[Ariel Red Hunter]

Originally Posted by Azhule

How much does a set of new "chop sticks" (aka "push-rods") cost anyways? It's under a fiver I'm sure

After the engine has broken in, the valve lifter,push-rod, and rocker arm for each valve are a matched set. It's your bike, do whatever feels right.....ARH

[Ariel Red Hunter]

Originally Posted by ben2go

It sounds like to me that the valves are hung open and possibly the rings are stuck. I've seen a crankcase vent like that from a lot of moister in the air and heavy use of the starter to spin the engine.

Good luck.

Yes that is correct. I have had that experience of a valve hanging open on a Super M Farmall that I was fixing for a guy. He was sure it was going to need an overhaul. When I took off the valve cover, and started the engine, number two cylinder's exhaust valve wouldn't close all the way. I squirted MarvelMysteryOil on the valve stem, and before I could put the MMO can down on the bench, the valve was freed up, and the engine was running normal. I hooked it up to our M&W PTO Dyno, and it was pulling 52 HP at 1450 RPM. I let it run under load for an hour, changed the oil and filter, called the owner and said it was ready to pick up. Bill was $35.00. Of course he didn't believe me. I knew he wouldn't, which is why I left it hooked up to the dyno. Boy, was he surprised when he saw 52 HP on that dyno guage. Then he said $35.00 was a lot of money for somebody to squirt a little panther piss on a valve stem. Then I showed him the sorry, sludgy oil I had drained out of his tractor, the oil filter so gummed up it was a miricle if any oil got filtered at all. Then he decided that maybe $35.00 wasn't really that far out of line after all.....ARH