Won't start

[Evilchicken0]

Trim the ht leads back about 5mm on the plug cap ends them reinstall the caps.

I still think the problem will be above the caps because they share a common source - the coil or its electrical supply

[Mang]

Can anyone point me in the direction of a "how to do" on valve clearances. How much of the bike do I need to dismantle to do it?

[Evilchicken0]

Use the FZR600 manual - Haynes do one. The top of the engine is similar to the 400 and the steps are the same.

But generally ...

Remove the radiator, the rubber splash gaurd and sparkle plugs. Take off the carbs and then the cam cover (this should keep you amused). You can go further and drop the engine which is sometimes easier in the long run. It allows you to clean everything.
Take off the genny cover put some tape so the edge lines with where the crank cases meet at the front. Rotate the crank so the flywheel mark is level with the tape (thats where the cases meet at the front). Check No1 is at TDC and look at the camshafts. There are small raise dots on the cam journals they should be lined up with the two small pin holes on the camshafts - Take a Picture of this. The exhaust is at 12 O'clock to the head / barrel matin surface the intake is at 1 O'clock (nearer the carbs). This is TDC No1.





I'll do some more of this at lunchtime

You can check the clearances when the cam lobes are at 90 degrees to the valves and also when they're straight up so in therory you only need to turn the engine over once. Draw yourself a chart with 3 boxes for each valve so you can write the Existing Clearance the Existing Spacer and New Spacer.

Take off the cam chain tensioner and cam journals .... do the journal bolts a little at a time, mark and photograph them so they go back in the same place and orientation as they came off.
Use a magnet to lift the cam follower out and you'll probably find the spacer underneath it note the number on it and replace it. When you've done them all sit down and calulate the best spacers for each of the valves (theres a sheet somewhere to help I'll try and find it). Order the new spacers.

When you fit the camshafts check your pictures first, lay them in and check the pics again. The dots on the journals and cams won't line exactly because the chain tensioner isn't on, the intake will move towards the carbs a bit. When everything is built up check the cams are right (sometimes it take a few goes to get them in the right place) and turn the engine over by hand. If it locks don't force it, it will feel tight as the pistons get to TDC and BDC.

With this all done button the engine up, throw the bike back together and relax.

[Mang]

Thanks for that Evil.
I am away at the moment but will get onto it on my return.
Sounds fun.

[Evilchicken0]

Take your time - it's fairly straight foward

[Mang]

Well got back late this afternoon and had the chance to strip the bike to the stage I could measure the valve clearances.
Exhaust tolerances all spot on but sadly not the same for the inlet valves, the majority of them are less than 2 thou and some have no clearances. With no clearance as a starting reference how the chuff do I work out what shim I need???

Evil were you able to find the "Ready Reckoner" for working out the shim sizes??

[Evilchicken0]

Sorry I was running around a bit and it slipped my mind.
You're going to need the inlet can out to find the size of spacer

[Mang]

Evil

Thanks in advance for sorting the chart.

My real confusion is –

If there is no discernable valve clearance then it may be correct to assume there is in fact a “negative” valve clearance i.e. the valve is constantly depressed by the none lobed section of the cam. If this is the case do I make calculations base on the gap being zero for the purposes of shim height calculations. My thoughts are that if the valves are constantly open then I may need to “take a little height off” the existing shim height (by maths not by filing!) to make the final clearances fall within tolerance when I put the new shims in. Do you see what I mean?

Mang

[Mang]

Marginally confused as to which mark on the rotor is TDC - is it the larger of the two marks?

[Evilchicken0]

There's a small mark on the fron face of the fly wheel - it line with the chrome screw on the cover, but the mark you want is on the edge or skirt there's a mark with "T" by it.
Put a pencil (point upwards) into the spark plug hole of No1, and you'll feel the top of the piston move the crank forwrds to TDC a little and you'll see the pencil move up and stop - that's TDC. The Cam lobes will be at 9o'clock EX and 3 o'clock IN and the cam marks will line up with the cam followers.

Set the engine to TDC before you remove the cam, so you can put it back in more easily. You can also put a mark of paint or tippex on the cam gear and it's corresponding camchain link.