Re Valve clearance

[Richard Headon]

Hi guys
I am rebuilding fzr 400 engine when I rebiuld it can you tell me how to set the valve or tappet cleanance the head is to go to a engineering comp. and will reseat the valves but I though that I sould ask before I let them start. It has jap writing on where the Egn no should be but is the same as the other Egn. I have a 1WG (fram no 1WG084 172) if this helps.

[Evilchicken0]

There should be a workshop manual kicking around here or the web but it's similar to any other DOHC enginge with shims under the cam followers.

Set the crank to TDC and the cam lobes on No1 should both be parrallel to the head (180 deg appart) allowing you to check No 1 exhaust and intake. Look at the cam lobes for No2 and No3 and check the valves where the lobes are 90 deg upwards to the head (intake No2 exhaust No3 it could be the other way round though). Make a diagram and note the clearances down.
Now rotate the engine to BDC and check No4 intake and exhaust and the other two of Nos 2+3. Fill in the diagram.

Rotate to TDC and remove the cams. write down in your diagram the shim thickness for each valve (really you should measure them with a vernier). Add the two values and subtract the desired tollerance to equal the desired shim thickness. Go to the nearest shim available and install them, you can move a few around so you buy fewer. Reinstall the cams with a bit of assembly grease on the lobes and recheck the tollerances.

Make a cuppa tea and dunk a biscuit.
I may have got this wrong but then again I'm still doing IMI level 2

[KIYOSHI]

If the head is off set the clearances before building the engine. Saves loads if time when you need ti change the shims.

Dont forget you will need to check the valve to piston clearance if you have the head skimmed .

[Richard Headon]

Thank you guys this has been helpfull.