If the cam cover gasket and the right cam sprocket gasket are still usable,you can just smear a light film of Permatex around them. If in doubt,replace them.

 

Ok OPT, now I'm going to ask some questions that I'm embarrassed to ask.....I ordered a new camshaft,exhaust rocker and carburetor. The carb I can do in my sleep. It's the cam I'm worried about. You gave me good instructions in a previous post after I get into the motor but here are the questions I'm embarrassed to ask but I've never done this before so here goes....I drain oil first,correct? How about coolant? I assume I'm not going to lose much except for whatever is in thermostat housing. Am I only removing components from the left side of the motor? Is the shift lever going to need to be removed or can I work around it? To refresh your memory, this is a 95 magnum 425 2x4. Again, I know these are novice questions but I have to learn I guess. I don't have the cash at the moment to take the quad in at $90 an hour ! Thanks in advance and I'm open to advice or tips from anyone else reading. I don't have a manual by the way.

 

Couple things I forgot to tell you also..You can crank the engine up until it's warm,drain the oil tank, crank the engine up for 10 seconds only!This can remove the 8 ounces from the sump. Then remove the oil filter to get the rest.Then remove the lower fitting from the oil tank after you drain the oil.It has a screen that may or may not have shavings on it,but best to check/clean anyway. Use a little teflon tape on it and screw it back in and tighten the nipple to the mark on the oil tank.When you go to crank it back up,first pinch off the upper tank vent line right at its nipple as there's a slit in the hose for condensation drain about 2 inches down from there.Crank the engine up for about 20 seconds and kill it. Remove the vice grip,clamps,etc from the vent line. You may hear a hiss of air entering the tank. That's a good sign the oil pump is primed.During this time leave the radiator cap off and let the fan cycle on and off.The radiator level should drop when this happens and any air in the system should purged.Top off the radiator and recovery bottle.These covers have to be removed:thermostat housing to be able to get to the small cam cover to remove it and the right side rectangle cam sprocket cover to access the 3 bolts on the cam sprocket. Sprocket and chain can just drop down out of the way.After the rocker blocks are remove,the old cam slides out the left side and new one slides in. Use some engine copper paste or some good assembly lube for the cam journals and lobes. With the rocker blocks back on align the plated link with the crank sprocket and case mark(shown in the pics) two plated links on the cam sprocket(pics on that also) pull the cam over and the sprocket in,turn the cam until the index pin aligns with the sprocket and push together.Blue lock tite on the 3 sprocket bolts. Then the cam cover and thermostat cover can be replaced.Install the tensioner with the shaft pushed all the way back. Install the right side cover after you adjust the valves. Stator,flywheel and recoil next. MARK the stator plate first before you remove it even though it's mark may be close to the engine case mark.Pull the recoil slowly around and the tensioner will adjust. Hope this helps,my fingers are tired.

 

Thanks for your quick response and advice. I should be receiving my parts on Monday so I'll let you know what happens after I work up the nerve to tackle this thing. Haha

 

Ok , so I took the valve cover off my magnum today. The exhaust rocker seems to be moving as much as the two for the intake. I did check the valve clearance and they all seem about .001" tight. I don't know if that's enough to make a difference but the .005 gauge will go snugly but the .006 won't. The exhaust lobe doesn't seem to have any scoring but I didn't take the rocker off yet to check it . Should I replace the camshaft anyway since I have it apart or should I adjust the valves and put my new carburetor on when it comes and see what happens?

 

Less work you have to do the better. Just look at the cam lobe as you rotate the engine over with the recoil.The lobe is the same height as the intake lobes. If it appears ok,no scoring,just set the clearance and install the new carb when it comes in. On these Chinese carbs I'd take them apart and make sure everything is clean,jets are the same as the oem carb. Still the oem mikuni is the better carb and unless rally trashed up,the carb kit I showed several posts earlier can fix one up.NEW SHINDY CARBURETOR CARB REBUILD/REPAIR KIT FOR POLARIS 425 MAGNUM 1995-98 | eBay I know the kit is not much cheaper then the complete knock off carbs,guess that's why so many people have gone to them,but don't get rid of the Mikuni.

 

Finally got to looking at my Magnum again. I decided to take the old camshaft out anyway to examine it for the heck of it. Upon further examination , I noticed chunks out of the intake and exhaust lobes and the exhaust rocker has a gouge in it. I replaced the rocker and put the new camshaft in. I don't know what I was worried about because it wasn't hard at all. I timed it per your instructions and a couple videos I watched. No problem. New camshaft immediately sounded better just while cranking. Bike won't start but will occasionally fire and when it does fire , I see smoke shooting out from somewhere in the front of the motor. I can't tell if it's coming out of the exhaust or the head gasket or what. I hold my hand over the spark plug hole and I'm not 100 percent but it feels like I may be lacking full compression. Any thoughts ? I remind you the quad was running very rich before all of this....

 

Check that the decompression device spring is set right and the actuator moves and flips back. If you're not careful when you install the cam the spring and actuator can slip out of place. Double check that you have the cam chain in time with the flywheel tdc mark and that the cam sprocket alignment pin is dead center of the head. The smoke could be coming from exhaust pipe gasket at the head or an exhaust pipe donut could be worn/leaking at the first joint of the exhaust pipe that held by the springs.

 

spring was good as well as timing. Rocker arms were so tight that they wouldn't budge at all. Loosened them up and the quad started. What would make the rockers so tight?

 

when i say i loosened the rocker arms i mean the valves were too tight. How do they tighten on their own?