3AJ CAMCHAIN
 

HI All i have noticed at standstill and at 2-2/5 rpm my 43000km 3aj has a distinct rattly noise. below or above this rpm all seems fine.i have checked the tensioner and found it to be at the end of its adjustment.does these symptoms sound like a camchain replacement is needed? if so i plan to go the endless route as described in an earlier post.can i also replace the tensioner blade this way or is it a cylinder head off job? also if i remove the left side engine casing,how much oil can i expect to come out? do i need to drain the oil tank first? any answers greatly appreciated,thanks T

Changing oil is ALWAYS a good idea.
This is definitely a worn cam chain.
Alternatively, lay the bike down on R/H side......
Remove L/H cover and flywheel. Remove cyl head cover but not the cyl head. Replace cam chain.
All greatly facilitated by putting piston at top dead center.

Auke

thanks auke, can i replace the camchain guides using this method?

Yep, you can. But I have never seen worn guides on a XT / TT, and believe me I have seen a couple of really trashed around engines. So check before you spend the $$ or whatever.

Auke

well, got the rocker cover off,lhs engine casing off, anyone got any tips on how to lock the flywheel in order to loosen the centre nut ?

Are you able to take & post pictures of your surgery? I imagine there are more than a few of us who have the threat of a camchain change hovering in our near future!


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was thinking along the same lines myself! we could have a (how to) picture gallery. seems easier when you can see the actual photos! i will try and post some. T

Thanks! I did a similar thing a couple of years ago on my old MZ two stroker, apparently this helped quite a few people, see:
http://hjem.get2net.dk/bioscience/MZ...shaftseal.html

Harry

Oops, forgot that part...
Easiest is to also remove right hand cover and put a large spanner on crankshaft nut right side, or balancer shaft nut (spanner 30).
Alternatively, use an air tool to remove the nut on the flywheel.
Xcuse me again, this will mean that oil needs to be changed.

I sincerely hope this is the only thing I forgot.

Auke

cheers Auke, just one more question! with the flywheel off,how do you get the actual chain out? do i need to undo the two camshaft sprocket bolts,remove sprocket and take the chain out from the bottom? sorry for all the questions again! T

Hi hows it going, i'm off from london to oz next year and have just started preventative maintanence on the bike (3aj)my bike was also making the same sort of noise so i took the engine out which took 2 hours and was realy easy to do, and found the cam chain needed changing and also the cylinder was scratched.
my advise to you is if you have a bit of time, take the engine out which was a walk in the park and didn't take hardly any tools, and have a look at the girl. this way your know your bike alot better and have a load more confidence. I'm replacing the guts (valve springs, piston, camchain, gugeoun pin) which has cost 150 notes for the parts so no matter what the out come, its still dirt cheap to sort out

Yep, Remove the two bolts on the camshaft sprocket, remove sprocket. The chain can be slid out from the bottom while 'undoing it' from the sprocket on the crank.
Make sure to re-fasten the two bolts on the camshaft sprocket with locktite and make sure to get the timing correct.

Auke

Better ask then destroy ...

cheers guys, flywheel is refusing to budge!! tried putting some heat on centre but still won,t move! have also noticed some play in left side bearing! think this is gonna be a bigger job than i anticipated. gaskets,camchain and a new set of inlet rubber manifolds have been ordered,so no going back now! thanks again for all your help. no doubt i,ll be seeking more advice on the rebuild. T

Hey T - am following this thread with bated breath!

Harry

Flywheel: make sure to use a well-fitting puller. Leave the nut on, screw it on real tight. Then hit the center bolt of the puller hqrd with a hammer.

Auke