Turns, sparks work, no fire!

[Rasta-ninja]

Re-checked the timings and its all good, il give it a go jumping from a car!!

[Rasta-ninja]

right gave it a go jumping and got a little kindve grumble but no real starting, then massive backfire. Isn't this something to do with the sparks? or possibly back to my first enquiry about the coils...?

[Tirpitz]

You won't necessarily damage valves with timing a little out. My camchain tensioner broke at 6k and the camchain jumped a few teeth. I was on the road at the time The engine sounded as rough as feck for the few seconds it took me to kill it. Sum total of damage - new camchain and tensioner - not a single bent valve.

If I fell in a bucket of shite I'd come out smelling sweet

No matter how badly out your clearances were before you started tinkering it wouldn't stop the bike running. It would run badly but it would run. If it wasn't running before you setting the clearances won't have cured it. You have a pre-existing problem there, forget the clearances for now, your fault is elsewhere.

You say the plugs are clean but are they new? You may be getting a spark but the plugs may be breaking down once under compression. You want new plugs in and if that's not the problem it's 99% sure to be the battery. ZXRs need a strong, fully charged battery to fire with. Old fully charged batteries just don't do the business.

I'd be looking at changing the coils if this doesn't cure it. 2nd hand ones won't cost that much. With electrics doing the eliminating thing is usually the best way to get results.

[Rasta-ninja]

Thanks for the help Tirpitz. The reason i decided to change the shims is becuase all issues i'd had with my bike previously(i.e bad running, causing me to flood the engine on start up and just generally bad through the revs top end) had led me to thinking it was tight valves(bad compression). This was the case so i changed the shims. The wierd thing is my battery is about 2 months old, and sparks are about 2 months and 1 week( got them around the same time) so maybe the coils are the cause, how do you check they are fully working? I just assumed they were working because i've electrocuted myself to check all sparks are sparking and ive even tested them on bits of metal and seen the spark =S
once again your help is appreciated

[RedexRobB]

Are you trying it with choke? Backfire to me sounds like its flooding a bit.

Ive always tried starting with half choke and then when it grumbles thats when i might give it a tad more.

[Rasta-ninja]

yeah thats what i thought, so got plugs out to let the petrol in the cylinders evaporate then heated them,cleaned them and put them back in, tried with no choke and still no luck =S is it possible for the plugs to loose their ability to produce a big enough spark? By that i mean do the sparks need to generate a massive spark or is a little one sufficient enough? cos they are deffo sparkin hence the "grumbling" i've even tried using a lil throttle at grumbling but still no luck, i've ordered some new sparks though

[Tirpitz]

Yes, you need a very hot blue spark to fire. People think that because they've got a spark then everything is fine but that's not the case. If the spark plugs are old you could be getting visibly good sparks but they are not technically hot enough. Once in a humid atmosphere of the combustion chamber they get doused.

If you've got new plugs I'd be surprised if that's the issue, it's beginning to look like the coils. You may be producing poor sparks. You're looking at £15 per coil for 2nd hand http://www.ebay.co.uk/itm/Kawasaki-ZXR4 ... 563cbea996

Might also be worth changing the HT leads before forking out. HT lead is dead cheap. Then it's down to coils.

[Rasta-ninja]

with new sparks in it fired straight up. Before i started the engine work on it it had a really bad sound coming from the engine. I thought this could've been down to the valve clearnaces, but after doing all that it still has a really bad knocking sound. Took it to the mechanics n he said its F*cked, apparently your looking at 1000s to get into the engine and replace parts, only other option is to get another engine =S so im really stuck on what to do now, what do you guys think?

[cargo]

EPIC FAIL


You had a knocking sound and thought that was valve clearence issue...........................so you took the camshafts out to replace a shim or two.....................all that work for a knocking sound.........................................dear dear me what a sorry tale


And now you tell us that it will cost thousands to fix .............................yet no one has bothered to look and see what the knocking noise is..................


your mechanic is right up there with a chocolate teapot or toffee fireguard.

[Rasta-ninja]

well i had the noise beforehand and had one of the rocker arms replaced and the noise completely disappeared, the noise then came back again and i thought maybe clearances were too tight causing another rocker arm to be worn down excesively which was what the new noise was, clearly not... =/ on the bright side at least now i know how to do valve clearances and shim swaps... haha the mechanic said that it the costs were just due to the amount of hours spent getting into the engine and looking around £55 labour per hour it is!!!

[RedexRobB]

Well, you gone to the effort of learning about the shims so why not see what you can learn from fixing the knocking sound?

Did you by any chance get a good look at the cams n rockers while they were out for any obvious wear?

[Rasta-ninja]

with the shim change i had no idea what i was doing but i had a guide to follow, here i really don't know what im doing, got no idea how to drop the engine let alone take it apart. Took a look at the cams and they were fine no wear, the rockers though did all have a lil wear on them but i thought this was normal...? cheers for the help btw!

[Tirpitz]

Top end produces rattle. Bottom end produces knock.

Yes, you will be looking at £1000s if you have a mechanic do all the work as it's the labour that does it. But if you're prepared to do as much as possible yourself you'll only have parts and a bit of labour to pay for. I'd be tempted to strip the motor to find what is knocking before making an assessment as to whether it is economically repairable or not. You could have a basically sound engine with a worn big-end bearing. If you stripped the motor down to the crank and replaced the bearings yourself you would know you have a sound engine when rebuilt. Buying a 2nd hand one is a pig in a poke. I don't think this one is game over yet by any means provided you are prepared to have a go.

The service manual can be downloaded from this site. The rest is just pretty basic spannering - taking something to bits and putting back together again. Worse case scenario you make a complete hash of it and ruin the motor - you're no worse off than you are now then. So give it a go.

[Rasta-ninja]

in all fairness i've not dealt with enough engines issues(this being the first) to know the difference between a rattle and a knock but it does sound more like knocking to me. What you say about taking engine apart is right, so i guess il be taking a lot of pictures and really taking it slow. Be expecting a lot of posts from me about whats what and how it should look i know theres a manual for reference but its good to get a 2nd opinion. In the mean time i might be buying an sv650 from a mate, he wants £650 and ive been riding with him for a year so i know its a good bike and been taken care of, then once i get the kwak up and running i can sell it off =D

[Rasta-ninja]

the sv that is, the zxr is staying with me for a long time