On the compression stroke the jack lifts slightly and falls down under a load

You can register for free at autozone.com, listing make, model, year, and engine size of as many vehicles as you want. Then look under "repair guides" for vehicle-specific Remove & Replacement procedures.

Usually, you strip down the front of the engine, including the front motor mount (use a jack under the engine oil pan with a block of wood between jack head and the pan, that will keep the engine from falling down). All belts must be removed, and the crank pulley or harmonic balancer also removed so the timing covers can be removed. Before removing the timing belt, you have to set the engine at TDC of the compression stroke on number 1 cylinder-the cylinder nearest front of motor. Then you can see the timing marks for the crank and cam sprocket(s), with the belt cover removed. It is an involved procedure to replace timing belts-you must follow directions exactly. Go to autozone and look at the procedure to see how involved and if you feel capable, or better yet, buy a Haynes repair manual for your Mystique, about 26 bucks.

I don't know of any factory marks. You have to put the #1 cylinder at TDC of the compression stroke, then drop in the dist. so the rotor points to the #1 spark plug tower on the dist. cap. The rotor will turn slightly as the dist. shaft slides down, so you need to start the dist. with the rotor turned slightly back. When it drops down, the rotor will be pointing directly to the #1 plug wire tower. Repeat until you have it right. Then it will start, and after warmed up, set the timing with a timing light.

TDC (Top Dead Center) of compression stroke: there are two TDC's for each cylinder, the compression TDC, and the exhaust TDC. To find the compression stroke, pull out the #1 spark plug. With your finger over the plug hole to feel pressure, turn the crankshaft over clockwise with a ratchet and socket on the crankshaft pulley. As the piston rises on compression stroke, you will feel pressure on your finger (there is no pressure build-up on the exhaust stroke). As soon as you feel pressure, now just turn the crankshaft further till the piston is at TDC. You can use a straw or pencil in the hole to find the top, or just look at the pointer scale by the crank pulley. The mark or notch on the pulley will be at 0 degrees on the pointer scale, TDC of compression stroke-now drop in the distributor.

If you know the engine's number one cylinder location, you need to put it at TDC of the compression stroke, then you lower the distributor in so that the rotor ends up pointing to the #1 spark plug wire tower on the distributor cap. As you drop it down, the gear on the dist. shaft will mesh with another gear and turn slightly. You want it ending up pointing directly to #1. Get it seated, then you can start the engine and set the timing according to specs with a timing light.

To find TDC of the compression stroke (as opposed to TDC of the exhaust stroke), pull the #1 spark plug out. Put a socket and wrench on the crankshaft pulley and turn it in its normal direction (clockwise), with your finger over the spark plug hole. As the number one piston is rising on its compression stroke, you can feel the pressure build up under your finger. You won't feel any pressure as the piston rises on the exhaust stroke, only on the compression stroke. So when you feel pressure, you know the piston is rising on its compression stroke, and you can turn the crank on around until the piston is at top of its travel-the notch on the crank pulley will now line up with the zero degrees mark on the pointer scale beside the pulley. There, TDC of compression stroke. Now drop in the distributor so the rotor tip lines up with the #1 spark plug tower on the dist. cap.

Set the piston to TDC (top dead center) this is the higest point the piston will rise before moving on to the down stroke, either by lining up the marks on the crank rotor or a long screw driver (large handle so it wont fall in) down the plug hole and watch for the highest point lock or hold at this point. The cams should be fitted next on the 'compression' stroke meaing the all valves should be closed when the cams are seated (no valves being pressed by cams) generally at this point the cam lobs face away from the valves, next stroke down (ignition of fuel) valves should be closed with the exhaust cam moving round ready to rock on to the exhaust valve as the piston rises to the top again (4th stroke exhaust) as the exhaust valve lobe rocks off the intake cam lobe should be starting to rock on opening the intake valve on the down stroke of the pistion.
Trun the engine over by hand to make sure no valves are knocking the piston.
Should be as follows
1. all valve clearance free/rocking at ' TDC 1st 'down' stroke (ignition of fuel) valves closed exhaust moving round but not pressing valve ,
2. 2nd stroke 'up' exhaust valve rocking open and closing as piston tops with the intake ready to rock on as the exhaust closes and piston tops (exhaust),
3.3rd stroke 'down' (intake of fuel) as the piston moves down the intake valve should be opening.
4. 4th stroke 'up' compression of fuel all valves rocking closed as the piston rises for the compression stroke back to TDC all valves closed/rocking free.

Intake, compression , ignition and exhaust. (**** squeeze bang blow)

You may be correct about a loose spring. Check this:

Carefully lay the mixer on its back side to access the bottom of the mixer. Remove the cover screen covering the opening in the bottom of the mixer. Using an extension and appropriate socket, be sure the nut of the bowl lift rod is snug, slightly compressing the spring of the bowl lift rod.

If your so sure of no compression on #1 cylinder, lift the valve rocker cover and observe valve condition. both valves will have a very small gap tollerance under compression stroke. Because it's #1 cylinder you probably arn't looking at overheating problem. ( usually rear cylinders) Your lifting the head to be sure !

1. Park the Dodge on a flat, level surface and engage the parking brake. Put two wedges of wood in front of your front wheels and two behind them.
   
2. Put the jack under the back frame of the car and lift it up until the wheels are off the ground. Slide the two jack stands underneath the car right under the axles, one next to each wheel. Use the jack to lower the car onto the two jack stands.
   
3. Loosen the lug nuts with the lug nut wrench, and remove the lug nuts and the two back wheels.
   
4. Look for two bolts that are attached to the caliper. Remove them with the adjustable wrench. Lift up the caliper and set it on the axle, taking care not to let it fall and break.
   
5. Compress the brake pads which, in turn, will compress the underlying piston. If they won't budge, use a C-clamp to compress them.
   
6. Open the spring clips by prying with a screwdriver and take off the pads. And if the pads are stuck you can pry them off with the screwdriver as well.
   
7. Rub a little bit of silicone grease onto the back of each new pad and put the pads in the correct position. Put the spring clips back in place to hold the pads in place.
   
8. Put the caliper back in place and tighten the bolts.
   
9. Reinstall the wheel and tighten the lug nuts. Lift up the car a little with the jack and remove the jack stands. Lower the Dodge all the way to the ground. Retighten the lug nuts.
   
10. Lift up the hood and look for the master cylinder's brake fluid container on the driver's side of the car, closest to the driver. Top off the brake fluid, if needed.
    

You will need the following

• 4 wood wedges
• Lug wrench
• Floor jack
• 2 jack stands
• Adjustable wrench
• C-clamp (optional)
• Flathead screwdriver
• New brake pads
• Silicone grease

check basics 1st fuel , air, compression, spark , timming
then secondary compression ie crankcase air tightness
2 strokes need air tight c/case in order to draw in & pump mixture

check your tank breather is working,

has this saw been sitting a while ? if so might pay to rekit carb

check your carby diaphrams are pliable and inlet screen is not blocked and metering needle is set flush with chamber floor,
are hi / lo needles set base settings are 1-1/4 turns out from lightly seated , final hi setting is done while @ full rev and needs to 4 stroke slightly

check ignition spark under load ie while under compression load- could be a weak spark

check timming key

check for a air leak at cylinder / manifold block gasket or carb joint

check barrell bolts are tight everything been = engine should run

cheers