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Hi guys its me again with the engine rattle. Just been told by an apparent reliable source that my big ends have gone on my zxr!

Apparently the noise from the engine is the piston hitting the top of the engine. Can anyone relate to this as its doing my head in trying to raise the cash to buy new engine and if this bloke is wrong I'm gonna have to take it out on him :smt013

hmmm, if it was hitting the top of your engine i think the valves would have had it by now.

May well be the big end bearings tho, with just a small amount of play i think they get quite noisy.

Have you managed to loacte the whereabouts of the noise itself? And what exactly does it sound like?

Short of being a master mechanic there are only 2 ways to find out if your engine is fooked:

1. Bits of valve are being fired out of the exhaust / sticking through the side of the engine.

2. You / he / someone, opens her up and sees what is what.


If its a H model or early L I'll take some of the sting out of a new engine by buying the cams off you

Its a 1994. It sounds like a tapet on a car. As you rev the bike the noise gets louder but on tick over, it isn't there. Gonna take the engine out tonight and have a proper look, Jmez has got an engine for sale so if I get it out tonight ill let u know my findings in the morning or later on tonight.

Oh and the noise is coming from the top of the engine, not from the piston housing. The seems to be a little loss of power. Not as much as I thought would of if I had done a big end

Have you got a set of feeler gauges to check your clearances?

If not it would be a wise investment although if they have been out for a while the cams and / or tappets may be gone

Why buy a new engine ?

I it was me I'd have it apart and fix it. What ever it is that wrong
Sounds like cams or camchain or rocker/valves.......... top end anyway.

ZXR 400 engines are easy to build worst thing is trying to get the thing to sit up straight on the bench

id go camchain first. pull the rocker cover and look for abnormal wear. its not pistons hitting valves cos yer engine would not run after a few secs of running like that. check your cam chain adjuster too.

Hi guys! Fresh from the garage and p***ed off a bit! Managed to get the rocker off with the lump still in the bike. Couldn't take lump out in the end as the bolts were so tight to undo, ive snapped my only socket. Out to get another tomorrow. Anyway couldn't find anything wrong or any signs of damage or pitting on the cams, not that you can see a lot if im honest. :smt013

insurerman wrote: Couldn't take lump out in the end as the bolts were so tight to undo, ive snapped my only socket.

i'm presuming you've undone the nuts off the engine mount bolts first and not trying to undo the bolts on their own?

No I was undoing the nuts on the engine mounts. I managed to get one undone with a spanner underneath the fuel pump. Thing is ive had the bike for about 4 months now, and it was all taxed and mot'd and apparently recently serviced so I haven't really touched her. Now it looks like it hasn't been touched for ages. Nevermind, u learn by your mistakes i suppose.

Bit odd that it only does it when you rev it up. If its the cam chain im pretty sure it'll do it on tickover but quietens when you rev. Last time i heard an engine sound like that one of the piston rings had gone. You might want to check the valve clearances first before you take anything more apart, you nver know it could just be that.

Just had a cam belt incdent on my other halfs renault. very noisey at idle, but when you take it up through the rev range it quietens down.
When the covers were off and teh engine running - there was 1" play in each direction
albeit this was a cam belt not a chain


is there any loss of power?
blue smoke coming from teh exhaust?

and when did you last check your valve clearances?

what does the noise sound like? is it a quietish rattle? or more of a banging sound?

if you want to try and identify the problem without opening the engine up, you could always get an oil analysis done. the metal deposits in the oil will give you a good indication of what is wrong with your engine. It does help if the oil has been in for a while!

/Caz

No, it sounds like a tapping noise from the top part of engine. Only had bike 4 months so ive neva checked valve clearances. No blue smoke, its actually whiteish so that seems normal. I can recall that when i first heard the noise i was only a mile or so from my destination so i took it steady. When i started it up again 8 hrs later it didnt do it until a couple of miles up the road . All in all id say the bike has probabgly done about 10 steady miles since the noise appeared. There is no play in the cam chain and the tensioner seemed fine when i checked that the other day. When we diagnose the problem, i think ill arrange for everyone to come round mine and we'll have a party . Taking engine out tonight when i get home from work

Just had a thought, could be a sticking valve.