Camshaft chain removal

[ElJokerr]

So my '06 Ninja 250 has 30K miles and is making a rattling noise, more noticeable at idle than at acceleration or driving. I took it to two different shops, and both confirmed that the chain needs to be replaced... I plan to do it myself, though it's my first time (I do have a very good knowledge of how things work, taking them apart, and putting things back together). However, I would like to know if I need any special tools other than the regular handy ones you would find in any mechanics garage, and also what parts I need to remove... Obviously the camshafts must come off prior to removing the chain, am I correct? Suggestions and advice on this from people with first hand experience on this job is appreciated. Thank you.

[Motofool]

First, you should measure the elongation of the chain by yourself.

At 30K miles, it should be OK still.

Please, read this old thread:
http://www.ninjette.org/forums/showt...443#post592443

[ElJokerr]

Yup, every 10-link lengths I've been measuring are over 2.5in, which equals to 5in for 20-links, and service limit is 128.9mm (5in=128mm). So it's confirmed, the camshaft chain needs to be replaced...

[Motofool]

Originally Posted by ElJokerr

Yup, every 10-link lengths I've been measuring are over 2.5in, which equals to 5in for 20-links, and service limit is 128.9mm (5in=128mm). So it's confirmed, the camshaft chain needs to be replaced...

http://www.ninjette.org/forums/showp...&postcount=735

http://www.ninjette.org/forums/showthread.php?t=104334

[ElJokerr]

I just want to know, am I going to have to split the crankcase for sure? Cause there seems to be no way for the chain to come out, due to that little safety guide that is right below the crankshaft gear.

[choneofakind]

I saw a method posted a while back where a dude on youtube changed his dirtbike cam chain without cracking the case.

he cut the chain, tacked the new on onto the end of the old one, pulled the old on through while rotating the engine by hand, then just cut the old chain off the new one once the new one was threaded through there. Then check the timing and voila!

I'd probably crack the case instead though...

[ElJokerr]

Yeah I haven't seen the video but I know which you refer to.. I know some basics about welding, done a little bit of work, but I don't feel comfortably doing that to the bike. This will be my first time splitting it, is there anything special I need to know? Like gaskets, parts or springs that might come out? I already took off the whole top end minus rocker arms and valves, and removed the clutch.

[ElJokerr]

Fortunately, I didn't have to split the crankcase. I was able to get a grinder with a small plate that fitted in the small space and grinded down that little guide that goes around the gear on the crankshaft. Now all that's left is getting that darn timing right haha.

[quarterliter]

Is that little guide that you grinded down inside the engine?

[ElJokerr]

Yes that's correct, I grinded the guide down inside the engine to give me clearance to take the chain off and put it back together.

P.S. I have installed everything back, it won't turn on... It cranks, but it seems as if the piston is hitting the valve... When setting the chain for the timing, was the cylinder #2 the one that was supposed to be TDC?? Or was it #1? My service manual says #2... And that the EX mark on the exhaust sprocket is supposed to be lined up with the gasket, while the IN mark on the inlet sprocket is supposed to be lined up with the gasket as well. Also, when counting the pins in between the marks with chain tensioner installed, it's supposed to be 33. I'm wondering if my service manual might have possible made a typo?? Please clear up any confusion about this if possible. Thanks.

[Motofool]

Originally Posted by ElJokerr

................Also, when counting the pins in between the marks with chain tensioner installed, it's supposed to be 33. I'm wondering if my service manual might have possible made a typo?? Please clear up any confusion about this if possible. Thanks.

See this:
http://www.ninjette.org/forums/showp...01&postcount=4

Cilinder #1 is the left one when sitting in the sadle.

When mark 2T shows up through the visor, the lubes of the cams should not be pressing on any of the valves of cylinder 2.

Note that there are two top positions of the piston (two turns of the crankshaft) for each turn of the cam shaft.

[FvnnyL3tt3r1ng]

Can you post pics or video?

Just to cover the basics you did turn fuel on and connect all your vacuum lines correct? If you installed your throttle cable too tight the bike won't start. Have you tried bump starting it I've found that to override some minor starting issues so that at least you know your timing is right...

[ElJokerr]

Finally got the bike running. Sounds beautiful, no more rattling, runs great

[Motofool]

Originally Posted by ElJokerr

Finally got the bike running. Sounds beautiful, no more rattling, runs great

[alex.s]

thats an interesting idea cutting off the bottom chain guide. just make sure it never gets loose enough to skip a tooth down there.

[cuong-nutz]

Originally Posted by ElJokerr

Finally got the bike running. Sounds beautiful, no more rattling, runs great

Yes, the satisfaction of knowing it's running good

[n4mwd]

I just found this thread. Interesting. I have never heard of grinding the lower chain guard down, but as long as there is still enough of it left to keep the chain from hopping a tooth, then it should work OK.

Most of the time when people with a pregen complain about a ticking or rattling sound at idle that goes away under load, its nearly always the clutch basket.

A timing chain does not feel torque with the engine and only feels speed. So the faster the engine, the more it flaps. Load makes no difference.

The pregen clutch basket has a design flaw that makes it rattle at idle. By applying a light load with the front brake, you can make this type of rattle go away.

Every pregen I have ever seen in person has had a clutch basket rattle. Unfortunately, there is no real solution. In theory, it might be possible to use a newgen clutch basket, but I've never confirmed that.