Just bought zxr400 couple of problems

[DeividasVicinskas]

Hi there just got zxr400 got couple questions. The bike runs fine but around leg area is it supposed to be so hot?? Another thing sometimes when I come to full stop the engine just shuts off or idles low rpm and then dies. Lastly is the idle sound supposed to be different when you are in neural vs in gear? I can hear some sort of shaking sound. That's about it for now
The bike itself is a great condition, valves and carbs sorted out, oil is fine and filter is fine, it's pretty fresh the bike, its got 26k miles

[CaNsA]

[bendog66]

1. Its pretty warm there, there's an engine in between your legs

2. Idle mixture screws may need setting and a carb balance wouldn't hurt

3. That would be the notorious ZXR clutch rattle

[DeividasVicinskas]

Where are the idle screws? I tried looking for info online and I can't seem to find anything on it. Do I need to take off the fairings to access the idle screw?

[banner001]

it could be the idle speed screw, which is a cable attached to the carbs and is on the RHS of the bike, above the clutch cover.

[DeividasVicinskas]

Sorted rpm problem, now another thing when I am riding the temp is always all the way on Hot and when I stop there is boiling sound is this normal?

[banner001]

nope

check your cooling system for leaks, make sure when cold that your coolant reservoir and radiator are both topped up.

if you are still getting bubbling then its probably time for a new head gasket.

[banner001]

also, check the overall condition of your radiator, you should notice that its massive, especially for suck a small bike...there is a good reason for that. if your radiator if plastered with crap then your bike will be running hotter than it should, either attempt to gently clean the radiator fins without making it worse (dont use a pressure washer whatever you do...) or look for a replacement radiator, if its an L model radiator they are expensive, so be prepared to pay at least £100 for a decent one.

[banner001]

my bike has an almost brand new radiator on it, when im riding along the temperature never climbs above 1/3rd of the way round the gauge.

you might wanna look at draining and replacing hte coolant, maybe do a good water flush as well. you can drain the coolant from the LHS of the bike, also there are 2 small screws below each pair of downpipes that allows you to drain the coolant from the cylinder bores. check the colour of the coolant, and b on the lookout for rust particles/general crap in there.

if it looks a bit crap you might wanna buy some new seals and clean out your waterpump, all your coolant piping and the thermostat as these are places that rust can accumulate, its possible but unlikely that your thermostat might also have become defective and isnt opening, boiling your coolant in the bores and therefore sending bubbles of steam into your rad...you can test the thermostat opening temperature with a pan of water, and a thermometer.

[DeividasVicinskas]

Thanks a lot for your suggestions, I will definitely keep them in mind. Basically earlier today I took the bike to kawasaki garage, they put some coolant in it (not sure if it was coolant or water, it was on RHS of the bike, near the radiator, under 2 or 3 bolts), and it's all gone after like 5 minutes of riding! The guys at the garage said they will have a proper check on it tomorrow, and will tell me if it's something serious or not, one of them said they doubt it's the head-gasket, because when revving the bike there were air no bubbles and it would have some other problems I can't remember exactly right now. But yeah this is not great, temp went up from middle to the maximum in about 5 minutes of riding in traffic, oh and another thing the fan doesn't start at any point of riding, when stopped there is no fan noise, not even when you turn the key without ignition. I'll have a read through your posts again and see if I missed anything

[DeividasVicinskas]

Okay so thankfully it was just the thermostat. I completely forgot to mention it's the L9 1999 bike and they're not likely to have head gasket problems in the first place. The thermostat wouldn't open up at correct temp

[banner001]

no worries, glad you fixed it

[DeividasVicinskas]

Another thing, the radiator looks pretty worn too, was wondering are there any alternatives from the OEM L9 radiators that fit? Because they seem to be extremely rare, and I can't find anything on ebay

[banner001]

nope, its second-hand good condition (expect to pay upwards of £150) or a re-core (about £300)

[DeividasVicinskas]

Gotcha, I mean it's got a few fins bent but I assume that can't be doing any real damage and not worth swapping