Timing is pretty easy on these old quads.
1. verify you are at Top Dead Center.
2. With the cam chain cover off, make sure cam chain is off and the cam sprocket is not installed on the cam. On the cam sprocket you will see a line pressed into the sprocket. This line needs to point to a small lobe that is cast into the head at the top of the cam "window". Install the sprocket into the chain so that the line point exactly at that lobe. Now turn the cam so that the sprocket can be installed onto the cam.
3. Once you have it all put together, double check to verify at TDC the cam sprocket is aligned correctly.
4. You should be good!

 

say I sure do appreciate the help. I'm still having problems my 87 yamaha 225 moto 4 is backfiring out the carb , just had the valves done , but on my cam i have a F and a mark and I have it looks like a T and a mark , I put it on the F MARK because when i put it on the T mark i can't get the cam sprocket on am i not doing something right . with it on F it is tdcits where it will go either way its that far up. any Ideas would sure appreciate more help please. or if you know a link that i could take a look at on how to get this darn thing running. thx

 

The "T" is your top dead center mark. The "F" mark is the firing mark. If you timed it to the "F" mark you will be too far advanced and will backfire and not run so well. Make sure the "T" mark sits right in the middle of the timing hole. Make sure your cam chain tensioner is removed while you do this. You should have enough slack in the chain to install the sprocket in the chain so it lines up with the bump in the head and then turn the cam to mount to sprocket.
Let me know if you still are having trouble and I will pull the cover off my 225 and take a few pictures for you.

 

I"ll look at it tomorrow if I have a chance and let you know what I find out thx agian. do you mean on the T or the mark after the T.

 

Line up exactly on the "T", that is your TDC crank position. then like they said before, loosen or take off the cam tensioner and make sure the cam sprocket line is matched up to the little casting mark on the head. With the cam chain loose, you can "walk" the links over the teeth to get the sprocket to line up. After you get the cam gear back on the came, you should have both lobes in position to set your valve lash, then make sure you put the cam chain tensioner back in, and you should be good to go.
My first ATV was a 1986 Moto 4 200, started and ran great, super quiet, I would take it ice fishing and it would start no problem after sitting out in 10 below weather all day. I especially liked the air box intake, right up by the handle bars, I would always amaze my riding buddies by running in water up to the racks and it would just putt away, making bubbles with the exhaust !!

 

i have a 1987 moto 4 225cc and i just replaced the piston rings and got everything put back together and set the timing but my problem is i can not get the chain tensioner to go back in , please help