www.zxrworld.co.uk

Based on the advice on the forum, I think I'll take the plunge and swap the cam-chain
on my H2.
Using the manual on this web site, there's a couple of areas I'm not sure about, and
wondered if you guys could fill in the blanks. Some of these might be really obvious
but this being the first time, I don't want to screw it up.

Step 1 Turn the engine so that the timing mark on the crankshaft shows TDC for
cylinders 1 and 4. Daft question perhaps, but how do you turn the crankshaft?

Step 2 Marking the camshafts. Is there a best way to mark the camshafts against
a point on the frame/engine? The manual shows lining the camshaft timing marks
against the upper surface of the cylinder head, but I want to do it without taking the
engine out.

Step 3 Remove the camshaft caps and cams. When I release the caps and lift
the camshafts, is there anything likely to spring off?

Step 4 Feed old chain down through engine and off the bottom sprocket. To get the
chain off the sprocket, you need to remove the circular plate with the timing marks on.
Doesn't slackening the bolt holding this plate turn the crank? How do I know where TDC
is with this removed? ie is it keyed and can only go back on one way?

Sorry for looking like a real idiots guide......

Cheers
Stephen

Turn the crankshaft with a 19mm spanner or socket.............. it fits on to the timing rotor


The camshfats are already marked..........use them and the whole job is easier with engine out

When you remove the camshaft caps do so very carefully make sure that you slaken the bolts even so the the caps lift off square there is a little flange on the camshafts the fits into the caps whic can break...............nothing will spring out


What I do is losen the bolt for the timing rotor first before setting the crankshaft postion. however it is keyed so can be lined up again

To get the chain off you will need to grind away some of the bit that sticks out stopping the chain from coming off. However one forum member (Zimm I think )has got the chin off just by carefull wiggling of the chain and crankshaft.

Great advice thanks. Dropping the motor may make changing the chain easier,
but that's a big job in itself for me. I'll give it a go with the motor in situ as a
first attempt. What could possibly go wrong.... !!

cheers
Stephen

i would line the marks up with the engine in situ then drop the engine to swap the cam chains.

Hi,

I have tried and tried to get the camchain off the crank sprocket without grinding the casing but cannot do it. Even if you put the chain on the crank sprocket and try to turn it into place it just scores the casing/damages the camchain.

I am purchasing a dremel and cutting disk tonight and I'll post a pic of the finished work if you like.

I wholeheartedly concur with everyone else, my engine is on a bench at the mo and If I was working in the frame I would be taking it out by now. Take the engine out.

All the best mate.

Mark

Mark,
Any pics you get would be welcome, especially if you're 'fettling' with a dremmel
to get the chain off the crank. Will save some heartache I think.

Stephen

OK. Mistake number one. Didn't realise all 4 camshaft caps had to be done
at the one time. Did the carb side first, stressed the cam-shaft oil feed,
and broke it. bugger.

Next question. Cut the old cam-chain to get it out. No point is wasting
time. Have tried unsuccessfully to fit the new one over the bottom sprocket,
so the dremmel has to come out. Spoke with Mark on this forum, and he said
to cut away the casing completely, under the sprocket. Obviously leaving the
section where the bottom of the guide sits.
Would the others on here, who've done this, grind the whole thing off, or just
grind down till there's enough clearance?

Cheers
Stephen

just grind it till theres enough clearance to get the new chain on.

cargo wrote:Turn the crankshaft with a 19mm spanner or socket.............. it fits on to the timing rotor

or pull the generator cover off and turn it by hand using the flywheel

cargo wrote:The camshfats are already marked..........use them and the whole job is easier with engine out

and marked on both sides too, so its easy enough to time up in-frame (well, on an H they are)

cargo wrote:When you remove the camshaft caps do so very carefully make sure that you slaken the bolts even so the the caps lift off square there is a little flange on the camshafts the fits into the caps whic can break...............nothing will spring out

What I do is losen the bolt for the timing rotor first before setting the crankshaft postion. however it is keyed so can be lined up again

aye

cargo wrote:To get the chain off you will need to grind away some of the bit that sticks out stopping the chain from coming off. However one forum member (Zimm I think )has got the chin off just by carefull wiggling of the chain and crankshaft.

this is where using the flywheel to wiggle the crank comes into its own gotta do the ZX4 this week, so i'll see if i can do it again, or if i got lucky .. lol.

zimm wrote:
this is where using the flywheel to wiggle the crank comes into its own gotta do the ZX4 this week, so i'll see if i can do it again, or if i got lucky .. lol.

Zimm you didnt get lucky, I did one your way last week on an L model , no grinding just a little jiggling

I have to say I disagree with the flywheel jiggling thing.............it's another engine cover off and maybe another rnew gasket needed.............

Definately think just grinding a little of the casing is best option but as ever each to their own.............great how this forum teaches and educates................

cargo wrote:it's another engine cover off and maybe another new gasket needed.............

its almost certainly another gasket needed .. unless it comes off almost perfect.

hands up who's wondered why their engine wont turn over after not using one on the left hand cover ?!



on the other hand, getting swarf in the engine isnt good news either and whilst you may be careful, others may not be, and sometimes toad just happens .. lol

ok,

just done the ZX4...

no grinding, and genny cover left in place ..

put the 6mm allen key that holds the ignition rotor back into the crank so you can use the allen key to rotate the crank, off it popped, and in it went ..

just line up the teeth on the crank sprocket so they straddle the offending bit on the casing and there's enough clearance to remove/fit the chain.

Zimm,

I wish it worked out that way for me but there was no way that was happening on mine bud.

Offending tag has now been cut off and the new cam chain is in place on mine, not sure how GT185 got on.

The amount of knowledge on here is great. Cant speak for GT but cheers guys, saved me losing temper.

Mark

do it hardcore. Engine in the frame. ive done head gaskets with the engine in the frame and the cam chain. bit fiddly but can be done