1991 ZXR 250C stuff

**justinx** · 25th February 2007, 20:25

Hi all,

I am new to riding and have recently purchased my first bike - a 1991 ZXR 250C.

I have a few questions that I was hoping some of you could answer:-

1) Engine Oil: I was told to use Motul 5100 15w40 as this is the best oil to prevent clutch slipping. Does this sound correct?

2) Brake disks: The front and rear disks measure 3.2-3.3mm. The service limits is quoted as 3.5mm. Does this mean I must replacement them immediately?

3) Brake pads: How do I tell these need replacing? Wear mark?

3) Tyres: Rear tyre is a GPR100 with plenty of tread. The front is a GPR80 that needs to be replaced. Do I put a GPR100 on the front to match the rear or another GPR80?

4) Air duct thing: I removed the left side lower fairing to take a peak around. There is a rubber duct that looks like it forms part of the air intake? There is oil residue in side the rubber duct. Is this normal?

5) Idle noise: At idle there is a significant rattle/noise that seems to go away when some load is put on the engine (hold brake tight, bit of gas and let clutch out fractionally). Research indicates it is possibly the cam chain / tensioner. Does this sound right? Will I have to replace the chain and tensioner? I know the cam chain tensioner was done about 15,000kms ago.

That should do for now.

Anything else I need to be aware of with these bikes?

Thanks in advance

Justinx

**Wheeliemonsta** · 26th February 2007, 09:10

Gidday Justin,
Will answer in the order you've asked...

1) Engine Oil: Motul 5100 is fine, Golden Spectro is another worth considering - a good quality semi synthetic changed regularly (5000 k's) will keep the old girl happy for ever... Change the oil filter everytime & stick with O/E (Original Equipment)

2) Brake Disc's: It will depend entirely on how pedantic the person doin the the W.O.F is at the time... Yes - its a legitimate reason for them to fail you as they are under the manufacturers specified service limit...

Freddies Disc's (Graham) in Waihi - 07 863 1110 will replace the rotors on your carriers for signifacantly less than what you will pay for brand new discs (around $480.00 each for new disc's)

Yes - you should be looking at having them replaced a.s.a.p

3) Brake Pads: If you remove the caliper from the fork leg there are grooves in the pad surface - these are more to clear water & debri away from the rotor surface than anything else, but, are a helpful guide as to what sort of nick your pads are in...

There should also be a "wear plate" which will contact the disc as the pads wear down - however alot of people bin these when they replace pads for some unknown reason !!!

Again O/E is best here - aftermarket pads will just chew the rotors to bits in no time flat, work on around 25 to 30 thousand kays out of a set of pads under normal condtions...

4) Tyres: These are a very personal thing - listen to what people have to say by all means, but in the end the decision is your's... I.M.H.O the GPR's are well suited to the ZXR's performance

5) Air duct thing: (Nice terminnology !!!) It's most likely the atmospheric vent come drain from the air cleaner assembly - yes a small amount of oil is ok out of here... If you ever actually saw what goes on inside an air box at high rpm you'd be bl**dy amazed that crap didn't literally piddle out of the breather's

6) Idle noise: Without listening to the bike I won't say for certain, however a educated guess would be the old "ZXR Cam Chain Tensioner" scenario... They simply wear out in service and don't tension the cam chain properly (light mettalic rattling noise at idle, normally dissapears as engine speed / load is increased)
Simple way round this is to replace the tensioner & sometimes the chain, dependent on its state... The tensioner comes as several individual bits, not as an assy - I would also suggest having the valve clearences checked if the bikes done over 40k k's & you are unsure when they were done last...

As far as I'm concerned theres only one way to do things...

& thats properly

Go fourth & enjoy your toy, there a great bike...

Cheers

**Panther** · 26th February 2007, 09:24

heya

4) replace the front tyre with either a grp 100 or a gpr70 (if you can still find grp 70 fronts as the tyre has now been superseeded) ive got gpr 70s on my zxr and the rear is oversized which is why most people run 70 front 100 rear, which is sposed to be the best you can get, where 80s are refered to as poo.

5) all zxrs have some cam chain noise just depends to what extent it is and if you're flush or not

oh yeah and don't ride her totally like a nana these things were made to rev high! ya seem to get the most pull between 12rpm and 16rpm imho.

**Panther** · 26th February 2007, 09:26

also try this thread

http://www.kiwibiker.co.nz/forums/sh...ad.php?t=42596

**N4CR** · 26th February 2007, 10:57

1. 15w50 5100 motul actually but yeah that is the best oil i've used in em and others with sucess stay away from silkoline that mt eden uses.. gargh.

2. brake discs... the tolerances are so close at production that it's pretty hard to meet them with a 2000k old '06 bike... enough said. i was 1mm off minimum tolerances when i had to re-cert mine.. they don't bother checking them anyway at most places. well yet to come across one anyway.

3. just visually inspect the pads they should wear evenly and not on an angle, i'd look at replacing them at around 1mm left they will make grinding sound just before they go.

4. gpr 80's are not made any more they are actually just the old gpr100's so chuck one of them on it gpr10sp or whatever the new gpr70's are are the best for them they are sticky as but gpr100's are enough for pretty much everything (worked for me good enough ask anyone how i rode that thing ^ its in my avatar haha), just make sure the correct size is fitted don't go oversize or you will lowside as tyre angle becomes too steep.

5. oil residue is caused by oil breather line not being connected to bottom of airbox properly or the chain oil flicking up on it, it's a 16 - 17 year old bike and nothing is perfect... it could also be just oil from if the breather line was loose at an earlier period. nothing to worry about unless you have oil pissing out.
the air duct is the main intake for your bike into the airbox, not the 'kras' tubes which do nothing apart from put cold air behind the radiator.

6. yeap it's the cam chain and or tensioner often it's just the tensioner. the parts are jack all just the work is costly so try get someone you know to do it or bring it to the spanner night maybe

. 15000km you do get some noise after replacement it will get real bad around 30-35k.. depends on each one i got alot of kms outtta mine. when it sounds like a diesel it's time to replace it as it'll be eating rocker covers.

**justinx** · 27th February 2007, 19:04

Thank you all for your responses so far. Much appreciated.

Wheeliemonsta:
Brake Disc's: Ill give Freddies Disc's in Waihi a call and see what price he can do them for.

Brake Pads: The rear pads still have a V groove in them. Ill will inspect the front pads this weekend as see how worn they are. I have noticed the wear marks on the front disk are odd (non uniform). Narrow wear on one half and wide on the other -> warped disk maybe?

I do suspect something is out of kilter as when I use the front breaks its not so smooth a bit jerky?.

Tyres: I will stick with the GPR as my rear (GPR100) is still good. Based on recommendations thus far i will go for a GPR10sp for the front.

Air duct thing: = Air intake box: After comparing with another ZXR the air cleaner drain pipe has actually been broken off along with the catch tank being removed. So any oil/water is just sitting in the intake/dripping all over the show. Will try and sort something out to stop that.

Idle noise: The bike has done 70,000kms. The cam chain tensioner was done as 55,000kms. I have no idea about the valve clearances (valve shims). Is it expensive to have them checked / replaced?

Sallo:
I’m doing my best not to ride like a nana

But still getting familiar with the bike and riding in general. Thanks for the link too. Already subscribed and keeping an eye on it

N4CR:
1. 15w50 5100 motul: I was actually going to ask for clarification on that because I realised that they don’t actually do Motul 5100 15w40. So you defiantly recommend Motul 5100 ESTER 15W-50 over Motul 5100 ESTER 10W-40? Whats the main difference. Motul’s website seems to portray 10W-40 slightly better? Do you recommend any particular oil filter?

2/3 Disk / Pads: As mentioned above the rear pad looks ok. Unsure about the fronts until I remove the calliper from the fork leg

4. So to clarify a GPR100 on rear and GPR10sp on the front gets a thumbs up? (^^nice avatar )

5. As above some of the oil will be caused by the fact the air cleaner drain pipe and catch tank are missing.

6. Offering it for spanner night is a good idea! Ill have a think and see what they think over in that thread. I have also had a PM offering help/cheap rate so that’s another option.

Thanks all for your help so far!

Justinx

**rookie** · 14th March 2007, 20:01

Originally Posted by justinx

Hi all,

I am new to riding and have recently purchased my first bike - a 1991 ZXR 250C.

I have a few questions that I was hoping some of you could answer:-

5) Idle noise: At idle there is a significant rattle/noise that seems to go away when some load is put on the engine (hold brake tight, bit of gas and let clutch out fractionally). Research indicates it is possibly the cam chain / tensioner. Does this sound right? Will I have to replace the chain and tensioner? I know the cam chain tensioner was done about 15,000kms ago.

That should do for now.
Anything else I need to be aware of with these bikes?
Thanks in advance

Justinx

Congratulations on your purchase...the ZXR is a mint first bike to learn on.

Everyone seems to have covered most of the points but i'd like to add my own two cents to #5.
My bike has just ticked over 50,000kms and like most ZXR's has some form of a rattle mainly at idle. I know that the common rattle of the ZXR is the cam chain however bulk of the rattle on my bike is the due to the play between the clutch plates and the clutch housing. Considering your cam chain and tensioner had 'recently' been done i would say that this could be the same case for you. (Although if a manual cam chain tensioner had been fitted that could explain it aswell).