View Full Version : Putting Engine Sprockets Back In


Maddawg
October 28th, 2013, 11:19 PM
I have read about every guide I could possibly find, but I'm running into a minor problem.

I went through the procedures:
- Crankshaft was at 2T, from when I removed the Chain Tensioner and Sprocket
- Put the exhaust sprocket into place in chain
- Put the intake sprocket into place in chain

When I put the sprockets so that the timing marks align, and the chain has the correct amount of link pins, so that it is positioned correctly, on Cylinder 1 exhaust, the sprocket seems to touch the cylinder cap.

There are pictures below with the Sprocket aligned correctly (or what I think is correct) and incorrectly. When it is correct, Cylinder 1 exhaust touches one of the caps, and when it is incorrect, if I assemble it, it won't turn all the way around if I crank the alternator.

Anyone know what I'm doing wrong or what I'm missing?

Thanks in advance.

http://runofheroes.org/images/NINJA250/At2T.jpg
At 2T
http://runofheroes.org/images/NINJA250/At2TSlightlyMisaligned.jpg
At 2T slightly misaligned
http://runofheroes.org/images/NINJA250/Cylinder1ExhaustSprocketAt2TSittingonCap.jpg
Cylinder 1 exhaust sprocket at 2T sitting on cap
http://runofheroes.org/images/NINJA250/Cylinder1ExhaustSprocketSittingonCap.jpg
Cylinder 1 exhaust sprocket sitting on cap
http://runofheroes.org/images/NINJA250/Engineat2T.jpg
Engine at 2T
http://runofheroes.org/images/NINJA250/ExhastSprocketat2TSlightlyMisaligned.jpg
Exhaust Sprocket 2T slightly misaligned
http://runofheroes.org/images/NINJA250/ExhaustSprocketAlignedProperly.jpg
Exhaust sprocket aligned properly

Motofool
October 28th, 2013, 11:26 PM
Welcome to our site, Kyle !!!

The problem seems to be the lack of tension of your cam chain.

Search for DYI related to valves here:
http://www.ninjette.org/forums/showthread.php?t=5586

I suggest you service the chain tensioner before continuing.

Maddawg
October 28th, 2013, 11:33 PM
Thanks for the prompt response.

Wouldn't the chain tensioner go on after the sprockets, plates, and chain guide, but the problem exists before those things already go on?

Also, by service the chain tensioner, do you mean get a new one I assume?

Motofool
October 29th, 2013, 05:01 AM
............Also, by service the chain tensioner, do you mean get a new one I assume?

Please, see post #13 and other here:
http://www.ninjette.org/forums/showthread.php?t=140450

http://www.ninjette.org/forums/showpost.php?p=730300&postcount=67

The chain between the sprockets need to be free of any slack and rotating the engine without the tensioner or in the opposite direction can lead to problems.

No, the tensioner can be disassembled, lubricated and re-assembled.
Go to the end portion of this page:
http://www.theyeagergroup.com/2008_ninja_250_valve_clearance.htm

http://www.ninjette.org/forums/attachment.php?attachmentid=24910&d=1369531849

mgentz
October 30th, 2013, 05:05 PM
The #1 cylinder will be putting pressure on the exhaust valves. This makes installing the exhaust cam tricky. The trick I use is to lighly wedge a small screwdriver between the chain and the head so the chain does not skip.

I will say that I am running much higher spring pressure than stock. So my situation may be different.