fzr400 loud knocking noise

[mpotnoodle]

can anybody help me out i bought another engine for my fzr400 3tj,checked the valve clearances oiled the top end then turned the engine over before starting til the oil light went out all good so far put petro lin it and it starts easily but it has a loud knocking noise i checked the camchain tensioner and it was fine ,even tried another one all okay,i then took the camcover off and there is plenty of oil getting to the top end,i think it was a bit noisier with the cover off,i inspected the camshafts and there is some pitting on four of the inlet camshafts lobes not a lot but it is through the shiny surface and you can feel it with your nails,any thoughts would this be enough to cause the knocking noise as apart from this it starts and idles fine,if so can someone tell me how to set the timing on it
thanks mike

[Evilchicken0]

You need to find where the knocking is in the engine. Use an engine stephascope or a long screwdriver (where the blade goes all the way to the end) or a metal tube. Put it on various points of the engine and find where the knock is loudest.
Unfortunately it sounds like a big end shell. If it is then you might be looking at a duff engine.

Timing. With the Genny cover off the mark on the outside of generator wheel should line with the crankcase joint to the front of the engine. Check No1 is at TDC by putting a rod or pen down the spark plug hole until it touches the piston. Look at the cam covers they have a dot on each of them and these line with the all hole in the corresponding cam, also No1 should have both lobes pointing to each other. The exhaust mark is 90deg to the head / barrels mating surface the inlet is about 75deg (the dot is closer to the carbs). They only line up fully when the cam chain is tensioned.

[mpotnoodle]

i have another bottom end of an engine but it might be as bad as the engine thats in is it easy to check the shells as i could swap the top end over if it was okay,thanks for your help i`ve never worked on a small engine like these before
cheers mike

[Evilchicken0]

Good question .... um.

I think you can get to the middle two, but couldn't say about the outer ones. I don't have much experience of engine building but these aren't to difficult (this is other peoples oppinion).

If the knock is half speed it's in the cams. If your knock comes low down near the back of the engine it might be the exup, if it's loose or not connected they make a noise, it's not in time to the engine.

Static timing marks yesterday

[dobbslc]

It's not easy to get the bottom end apart to check the shells as you have to take the whole top end off the access two crankcase bolts under the barrels
Got to be worth checking the cam timing and shims although it does sound like the big end or main shells could be duff.
It could also be something like a loose flywheel or clutch nut...
A full gasket set for these engines is about £100 plus anything else that's knackered, can you take it back to where you bought it?

[mpotnoodle]

unfortuneately i bought the engine months ago but have never got round to sorting the old bike,but i have stripped it down today and the number four cylinder big end shells have turned and buggered the crankshaft,i have my old engine which is knackered up top but the bottom crankcase is damaged when i had an little tumble,i`ll maybe strip both down and make one out of two
cheers