What Next? [ZXR250A 1990]

[Stealthassassin]

Hi Guys,

We bought a 1990 ZX2R last weekend from a mate who'd left it sitting in the back yard for a year under covers. There were no storage procedures considered before the bike was left to rust. It faired pretty well, from what i can see on the outside anyways... A bit of surface rust but should scrub up ok.

Since getting it home, we have:
Changed Oil and Filter
Flushed the radiator
Cleaned out the tank.

Tomorrow, we'll do:
Spark plugs
Change the brake fluid
Clean the carbs (hopefully we can do this without removing them as i havent done it before??)
Change the fork seals and oil (if time permits)

Steps that will follow above will be:
Change brake pads
Lube cables
New tyres
Chain and sprockets
Blue slipped and rego'd.

Can anyone suggest things we may have missed or tips in completing what we are setting out to do? What would be on your checklist if you had a bike in the same circumstances?

Any advice will be greatly appreciated

Here's a pic just after getting it off the trailer

http://www.postimage.org/image.php?v=aVR5KG9

[Gosling1]

You really need to take the carbs off to clean them properly.

Changing fork seals ? Have you done this before ? It can be a prick of a job. Changing for oil is not as bad.

It will probably need a new battery as well. You need to check this first, as all the other good work will mean jack if you can't start it !

Good luck .

[Stealthassassin]

Changing fork seals ? Have you done this before ? It can be a prick of a job. Changing for oil is not as bad.

Hey Gosling1, thanks for the reply....

Yeah i have done the fork seals on my CBR250rr before, they arent USD forks like the ZX, but i am pretty confident with it..

Forgot to mention the battery... we picked one of those up last night too. I didnt realise you need to charge them before using them though, so i have asked a mate to borrow his charger (if he can find it).

Do you know of any good guides in taking carbs off and cleaning them? I have opened the air box and can see into the carb throats (?) - I cant just spray cleaner into there?

[mike-s]

the carb gumming occurs 90% of the time within the carbie jets which are inside the float bowls, perhaps some of the air jets in the carb will gum up, but thats not too likely. [edit] just pointing out the airjets are at the throat of the air intake on the carbies.[/edit]

[Gosling1]

taking the carbs off is not an insignificant job - all the cables, hoses etc have to be removed, the airbox taken off, the manifold clamps loosened, and the carbs should then be able to be removed. They will need some encouragement, especially if its the first time they have come off the motor.

Once they are off, you can remove all the float bowls and this gives you access to the jets, which can be removed, cleaned, and replaced - IF its needed.

As the bike has sat for some time without being run, the probability of the jets being gummed up is pretty high, so its worth the effort to take the carbs off and clean everything out. There is a product called Clean'R'Carb, its a pressure-pack, and its great for removing any old fuel deposits (they look like varnish) from the bowls and jets. Just take your time, do 1 float bowl at a time, and its an easy job. Its time-consuming, but still pretty easy. It will also help if you have a source of compressed air to blow the jets clean, don't rely on your own air-pressure fo this, its not enough........

As per Mikes advice, the air-jets that are located in the carbie throats will need a spray with the carby cleaner and a blow out with compressed air. If you don't have access to a compressor and an air-duster (air gun), its worthwhile organising one.

[Stealthassassin]

Well you were absolutely right when you said that removing the carbs was no insignificant task.

I took the airbox off with ease and sat staring at the bike for the next 30 minutes trying to figure out where the manifold clamps were. After another 15 minutes of head scratching, realised that you need to drop the radiator down in order to get at them properly.

Anyways they are off. I am absolutely dreading the task of putting them back on and tightening the manifold clamps

Would a can of compressed air do the trick cleaning the jets or is it a bit under powered? Same question really for the tyre pump that i have, it's one of those cigarette lighter ones, too weak?

[Gosling1]

When you go to re-fit the carbs, spray a little bit of wizards piss around the inside of the rubber manifolds. This will not harm the motor (don't empty 1/2 a can in there), and will help the carbs re-seat properly.

A can of compressed air will do the trick, just give each jet a quick blast - You don't want to run out of air with a couple of jets left .

Those battery-powered air-pumps are no good for this type of thing - they don't have the 'ooomph' needed. They are great for pumping up tyres, and thats about it.

When you get around to re-fitting the carbs, *make sure* that they have seated properly in the manifolds. Generally, you can feel when they have seated into their proper position. With the clamps, just take your time. Its really important to ensure that you get all the clamps done up good and tight, to prevent any air leaks.

Well it sounds like your fair into it now, keep up the good work !!

[Stealthassassin]

Hey Gosling1...

Well... again, spot on about some WD40 on the rubber manifolds, easy as anything to get back on! I had more trouble trying to get the throttle cables all lined up and sitting correctly - i had to take the right hand switch block off to loosen the cables enough to get the carbs off, so getting that back together was a bit tricky.

Cleaning the carbs was pretty straight forward, i used a small peice of tube from my chain lube on the carb cleaner can and used the pressure to blow the jets through.. I ended up using one and a half cans of the stuff, just to make sure it was clean The only really noticeable stuff up was disintegrating one of the little o-rings that sits behind a tiny washer below the pilot screw.. I will change it if there are too many dramas, but for now its back together without it.

Also, i thought i was pretty damn clever by trying to balance the carbs by sight, i got all the butterfly valves lined up to what i thought looked spot on, but not too sure now...

Next thing i did was change all the spark plugs, and had to try and squeeze the plug lead connections to make a tighter fit
(you could pretty much breathe on them and they would pop out).

Pulled the tank and battery off my CBR, got some fuel from the tank and run it into the fuel line with a funnel and wacked the battery on the ZX, it fired up after a few turns of the starter motor A fair bit of whitish blue smoke came out - not crazy amounts, but a bit.. I leant down and felt the headers and found that cylinder 2 and 4 were not working... readjusted the leads and no. 2 came to life.. Still not sure about no.4 ....

Another thing i noticed was idle was cutting out if i left my hand off the throttle, i adjusted the idle screw, but that would only make it jump up to about 4K RPM - so that's why i am thinking the balance may be waaaaay out. The throttle also sticks a bit, but i am thinking that may just be dryish cables.

Well now im at a point where i dont really know what my next steps are.. I'm guessing i should see if there is fuel in the bowl of the carb above cylinder 4 and if that is ok, try fiddling with the plug lead a bit... But then what do you think should be the next steps? I dont want to buy a gauge to balance the carbs, so i think i will leave that to a shop to do... shouldn't cost that much i would imagine..

Thanks for all your help so far, it has been very much appreciated!!
Stealth

[Gosling1]

Couple of things to do:

Take the throttle off completely, and lube the bar, inside of the throttle tube, and inside of the actual throttle housing as well with wizards piss. Sometimes if any one of these 3 components is a bit dodgy, you won't get a smooth throttle action or return. You can squirt a bit down the throttle cables as well, but as long as these are routed correctly, you shouldn't get too much drama from the cables themselves.

Make sure the plug leads and plug caps are fitted correctly, it sounds like there could be some issues here. Also, make sure you have plenty of fuel in the system, putting in a bit to test things is OK, but it's better to have 1/2 a tank worth feeding the system, so you can minimise any problem areas as much as possible......

Its almost imposible to balance carbs by eye, this is one job that you need to get a shop to do, if you don't have the gear yourself. When the carbs are balanced properly, the motor should run as smooth as buggery, and idle really smoothly as well.

I would be sourcing a replacement O-ring and fitting it as quickly as possible. As this O-ring is part of the pilot-jet circuit, it will affect the performance of the motor around idle and immediately off-idle, for that particular cylinder. These parts are crucial to good low-speed running. Its a bit of rooting around, but each time you take the carbs on & off, the job gets easier ! One other thing, on some bikes, its easier to re-connect the cables at the carbs first, and then fit the carbs to the motor, rather than fit the carbs and try and attach the cables.

cheers

[mike-s]

Its almost imposible to balance carbs by eye, this is one job that you need to get a shop to do, if you don't have the gear yourself. When the carbs are balanced properly, the motor should run as smooth as buggery, and idle really smoothly as well.

The only thing you can do to do it by eye is get some fine piano wire and measure up the resistance. But that's only 2/3rds there and to get it perfect you can do better by synching them up with vacuum guages.

These parts are crucial to good low-speed running. Its a bit of rooting around, but each time you take the carbs on & off, the job gets easier !

Unfortunately i can vouch for this.

[Stealthassassin]

Thanks, that will be my next step tonight... Get the throttle working smooth. So wizards piss to the rescue again!

Once i get the o-ring, i will take the carbs off again (assuming i can't get to the screw while the carbs are fitted) and seat that back into the circuit as you've mentioned.

Just so that i have got it as reference if i forget, the cylinder that is not firing is not the carb that has the missing o-ring (i think that was carb 3). But i will check carb 4 tonight and see if there is fuel in the float bowl. I guess that if it does, next i will check for spark. The funny thing is, cylinder 4's plug lead was the only one that seemed to click on well.

The butterfly valves all seemed to be open the same amount with closed throttle and that's why i thought i had it spot on .. But i didnt measure it with anything... If i can get it idling and running smooth, i will take it to a shop to tune up. - Do they just attach the gauge up tp the float bowl drains to get the balance correct?

I am pretty confident with getting the carbs on and off now that i know it is possible (from your tips). It was pretty daunting first time round though.

Thanks heaps Mike-s and Gosling for all the continued help

[MiG]

With the clamps, just take your time. Its really important to ensure that you get all the clamps done up good and tight, to prevent any air leaks.

Not too hard though. I found that it was pretty easy to do up the clamps to the point that the rubber is starting to squeeze out everywhere.

[Daisy]

Do they just attach the gauge up tp the float bowl drains to get the balance correct?

That's to check the float level.
To balance them you need to connect a gauge to the engine side of the carbies.
I was lucky enough to get my hands on one of these;

carbsync.jpg (44.34 KiB) Viewed 3486 times

[Stealthassassin]

Cool, thanks Daisy.. Where do they attach on the engine side of the Carbies?

[Daisy]

Not sure about your bike, but usually on the top of the rubber manifold there are nipples with various vacuum hoses - fuel tap etc. You simply connect the gauges to each of those,making sure that you still have some way of fuelling if you're using the bikes own tank and it has a vac tap. Then at operating temp, making sure the idle speed is correct, adjust the carbies in pairs. I think for mine it was left pair, right pair, and then synchronise them with the centre screw.