www.zxrworld.co.uk

I'm having a bit of a struggle with this bike, having been a 2 stroke only racer for years, then spannering for matey with his R6 onto this zxr400 he's bought..

It's rough, but seems to have all the right bits. However there are some bits that concern me, being slightly mechanically minded..

The spec is;

ZXR400L
Carbon ram-airbox
Ported Head
Modified CDI, think the rev limit has been raised to 15,700 rpm
Total loss
BEET exhaust
I looked at the cams, and they are slotted. Are these aftermarket?

It's been to dynapro in Runcorn, had quite a bill of work and 74hp at the rear wheel (said the owner, the dyno printout was nowhere to be seen when we got the bike) but it revs up very well and certainly feels quite crisp. Yet to ride it though, might only have 3 gears!

Anyway, what I wanted to know is...

Are they meant to tick over? I know a standard road bike does, but whatever I try with this it refuses to Idle below 2000 rpm. The pilot screws were set to 3.5 turns out, I reset them to 1.75 as the autodata book instructs. But still no different. Is it down to the tuning? I raced a TZ250 for years and that refused to even run below 3k! I'm not bothered about it ticking over like, just if it should, then I'd like it to. Could be a sign of a problem along the line?

It sounds a bit rough, the clutch basket is a bit noisy bit it's to be expected I guess. But on the overrun, there is a slight knock. Sounds like a camchain to me but that looks ok, although embarrassingly enough I'm struggling to locate the tensioner, is it on the bottom of the motor on the RHS? Usually midway up the tunnel but I cannot see it! Or are these engines noisy as a rule, maybe some hp-killing noise dampening removing bits taken out of the engine?

The airbox doesnt seal very well, especially around the carb rubbers. I'm struggling to see a fix, anyone got photies of their setup with the carbs removed?

Thanks!
Paul

Paul, what did mike and chris say about it at dynopro? they have alot of experience with these bikes, second to none in my opinion, and should be able to see you straight very quickly.
3.5 turns out on the idle screws is not uncommon, neither is a 3k idle. A similar setup to mine, i liked the high idle as it does help with rear wheel hop.
It sounds like it has the bits you want on her, slotted cam sprockets are either standard zxr400 sp or kent or similar or regrounds, essential race kit. as is that rmkd airbox by the sounds
Where is the bike from? what number and colour fairing was it when you bought it and when?

Personally, unless i knew the history of the bike in depth, i would have the motor refreshed.

Jake, you know what? Did it occur to me to speak to them? Far too obvious for me I suppose it'd be the best thing, to phone them and ask. I'll get the receipts for the work later and give them a tinkle tomorrow maybe.

Got it off a guy between Abergele and Colwyn Bay, quite high up the hill. It looked a bit of a shed, but as you say has all the right bits on it including maxton suspenders, usual race garb like rearsets etc, so my thinking is it wouldn't take much to make it good. Mainly replace all the cable ties with nuts and bolts, sort out all the bodges and it'd be good. If the motor is right, that is! I'm not fussed about stripping and rebuilding the motor, infact I'd prefer to as it seems to be a bit incontinent from some of the surfaces, not a great sign. There seems to be numbers on each cyl. 50.6, 50.4 etc. What are these all about? Written in marker pen..

This is the bike as it was bought... Lovely colour or what!


Sorry for the shoite picture, we'd stripped it for painting within 10 minutes of removing it from the van!

Whats the usual deal with refreshing the motors? What do you replace as a matter of course?

Cheers!
Paul

That from a guy called steve? i think that was his name..
that bike was at dynopro for a while a few months ago i think, whilst it was up for sale..
I remember it looked a bit rough around the edges, but all there just needed a few quid spent on it.
Im not sure what the marking on head would be, poss compression? why someone would write that on the head tho i dont know.
Refresh would be head gasket, camchain and tensioner checked and replaced if needed, clearances, etc..
Dynopro will be flat out with last minute manx preps for everyone no doubt tho at the moment, so you might have to wait untill next month.
Im no expert but ive had a dabble with one or two zxr's and will gladley have a good look at aintree mate

Thanks Jake. I guessed it'd be known by someone on here!

It seems ok, just noticed that the exhaust is blowing so will have a look at that tomorrow. Want to take it for a run before Aintree, make sure everything is ticketyboo now rather than in practice!

I'll leave Dynapro alone then, forgot its nearly manxtime..

Here's how it's looking now..


Nearly there.. new bodywork would be great but lets see how the rest of it goes first eh!

Looking good

If the barrels have had the "kit" work done to them along with the head then it wont idle much below 2,500 add in a knife edged crank and that will jump above 3K

For a road bike I was adviced just to have the crank balanced to avoid this.

Adjustable cams either, SP, Kent or BEET - the BEET cams should ahve their company logo on them and are the best out there

I would have thought compression readings for the numbers, maybe done to monitor wear - try taking your own readings and see how the numbers stack up.

MM!

Cheers Mori. I did suspect it was down to the tuning!

Just need this weather to clear up for the weekend now