300ex problems

[truestreet300]

i ihave 2000 300ex which i just had the top end redone and iam having some problems timming the motor if i do it the way the manual says to do it comes up a half a tooth off when the motor is lined up with the t mark on the flywheel no mater how i try to set it up its always a half tooth off either direction it seems as though the chain has alot of slack in it and when the tensioner is released it pulls it out of time i tried for along time to try to get it to line up and i cant seem to get it maybe the chain is streched i dont when i took the motor apart it was off a half a tooth then i just thought the guy who owned it before me had it wrong the bike felt really weak compared to another 300 when it was running so iam trying to get it running right any help you guys can give me will be greatly appreciated thanks

[bwamos]

Your are probably dealing with some chain strech there.

It couldn't hurt to replace it. It never seems to line up perfectly on the 300.

Make sure when timing it that the chain slack is on the tensioner side, and also make sure you line up the timing mark on the crank with the wheels in the forward motion, so that slack in the parts are all compressed in the proper direction. I usually remove the spark plug, and put it in 5th, then roll it backwards until the mark lines up. Don't roll it forwards, or the part tollerance are all pulled in the wrong direction. (In neutral you can also use a socket wrench to turn the flywheel under the center plug, it's jsut easier for me to do it the other way.) It doesn't seem like it would do much, bit it can make about an 1/8th of a tooth difference. It also doesnt make sense.. but if think about it, rolling it forward would pull on the parts, like decelerating.. so you want to roll it backwards to compress it, as if the engine were running. It's hard to explain.

Once you do that, set the cam timing. And you'll probabaly have the cam timing marks line up about 1/4 of a tooth or so toward the rear of the engine due to some chain strech, make sure that the schain slack is on the tensioner side (rear of the engine).

[truestreet300]

well the chain fixed it in time fired up on first try this bike was soo poorely kept before i got it it wasent even funny the old chain was streched really bad compared to the new
now all i have to do is ride it and check the jets make sure everything is ok
thanks for the advice

[zeppelin]

imo i would replace the chain asap, if the chain goes, the rest of the top end goes, and the reason it is running poorly is probably because it is out of time by one tooth