The ZX-7R is misbehaving already! Start damn you, start!!!

[Whosthedaddy]

Went for a lovely spin on the bike, just shy of 90 miles in all with a mix of straight line A road speed and some twisty B road action, and it was faultless bar the rider making n00bish mistakes on a few corners

I did have some severe deja vu as when in the middle of nowhere the bike refused to start after I stopped to have a little walk about

The bike is a little fiddly sometimes to start with a combination of the clutch and side stand switch, but the engine turns freely and sounds strong, there is just a delay in the vroom and start

After a dozen or so attempts, I checked the fuses and petrol, I could hear sloshing but turned the tap to reserve just in case. Still nothing, but just as I was about to break out the mobile for some road side assistance, the bike turned and caught.

So off I go to fill up with some more jungle juice, went off to pay and again refused to start first time!

Even being a little down hearted, I still decided to randomly ride with no sense of purpose other than because I wanted to and to charge any deficit in the battery.

Just down the road from me is a bike garage so popped in to ask how much for a basic 'pre winter' service as its just too much like hard and messy work to dismantle half the bike to change the oil filter, and again the bike refused to start for 3 or 4 times?

The engine sounds strong but it seems to hate starting when warm?
____________________
Current : MSX 125 Past : CBR 900RR Monkeybike : c50 LAC : ZXR750 H2 : FZR600 : ZX7R P3 : YW100 : TRX850: Trophy 900 T309 : GSXR 600 L0: Monkeybike : XJ6S Whosthedaddy

[Cigaro]

Is it an automatic choke?

Sounds like that could be at fault, at a wildly uninformed guess.

[Whosthedaddy]

[hmmmnz]

welcome again to the wonderful world of kawafuckensaki
i had a spot of bother with mine as well, it turned out to be a dodgy lead at the coil end, just one dodgy ht lead will stop 2 cylinders from firing, and it was only when the bike was hot
try that
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[Whosthedaddy]

[hmmmnz]

your best bet is take the tank off un screw the ht leads 1 at a time cut about 1cm from the end of each cable and push them back into the coil and tighten,
do it to both ends, or buy some new ht cable its about £5 a meter and you will need 2 meters. https://www.mandp.co.uk/productInfo.aspx?catRef=501838 (£3 a meter)
if by some slim chance you have silicone leads, then rip them out and replace with copper leads, siliocone breaks down quite quickly,
and we all know that copper is the best conductor of electricity,(with the exception of silver)
have fun
may as well chuck in some fresh pugs while you at it
hopefully you still have you stupidly skinny sparkplug socket
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[Faldo]

Sorry Whosthedaddy, mine starts first time every time, but while the Kwakheads are looking I've got a quick question if i may:

Mine is never happy at 20-30MPH for more than 5 mins. The temp needle is quickly buried into the red. I've never heard the fan cut in once.

So my bike went in for a clutch / service today and I mentioned it to them and asked them to find out if there was a problem. They rung me up and said they couldn't find anything wrong. The guy told me that most Kwaks have to be virtually at boiling point before the fan kicks in, and says that he regularly used to see GPZs etc with modified manual fan switches. Think this is the way I'm going to go, any hints on the best way to do this and if this is a common problem?

Sorry Whosthedaddy for the hijack but hopefully an answer will be beneficial to us all. Hope you get your starting problems sorted out, I know how annoying it is!
____________________
Current: ZZR1400
Previous: ZXR 400 L9, ZX-7R P5, ZZR 400, ZX-7R P6, Bandit 600, GSXR 750 Slingshot, DRZ400, DR650, ZX10R C1H, ZXR 750 L1, ZXR 750 L3, '99 ZX7R P4, KTM 300 EXC, ZX-9R E1, TDM850

[hmmmnz]

lol, that is a super common problem, my fan doesnt cut in until 102'c and by that time its far too hot to cool it back down,
i have just disconnected the wire from the fan switch(bottom left of rad as you sit on bike)
lifted the tank, pulled the wiring back up, and out through the same hole as the wiring for the handle bars, and then connected it directly to a small switch,
i did have it wired in parallel, at first, but i always have my eye on the temp gauge, so in the end it was pointless.
best mod ever for a hot quaker
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[Faldo]

Cheers hmmmnz, glad it's not just mine then!

I'll get my bike back tomorrow so now I'll have a little project to do if I'm bored at work!

TBH, it's not often I ride at 20-30mph so although I knew the problem was there I did sweet FA about it, but I joined in a massive procession type ride through my home town with over 1000 bikers and I had to keep finding a space to accelerate hard to 60 ish and brake hard just try and cool the damn thing down. I looked like a right nobhead! I gave up in the end and had to find a dual carrigeway quick and cane it! Oh well!
____________________
Current: ZZR1400
Previous: ZXR 400 L9, ZX-7R P5, ZZR 400, ZX-7R P6, Bandit 600, GSXR 750 Slingshot, DRZ400, DR650, ZX10R C1H, ZXR 750 L1, ZXR 750 L3, '99 ZX7R P4, KTM 300 EXC, ZX-9R E1, TDM850

[hmmmnz]

yeah they are bastards like that, i can't even get into town in peak hour traffic with out it getting hot,
with the fan on it'll stay at a constant temp,
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[Whosthedaddy]

[bugsy46]

If the bike is running fine with no mishaps when riding then I would knock the HT leads on the head right away. If the ignition sytem cant cope with turning a bike over then its common sense that the bike isnt going to run well or at all under load. I would check things that would lead to poor starting in hot conditions. These would be fuel mixtures first off, checking that the choke is DEFINATLY returning. Also check for dirty wiring around the starter system ie clutch, sidestand
____________________
Laura - "And where did looks come into this and bugsy leave steven alone. You are not gods gift to women you may think you are but you're not."
Keith - "All the best"

[Whosthedaddy]

[bugsy46]

Thats right, the starter system can also prevent the bike from starting if there is a break in the loom etc as they are usually all linked. The fuelling though would be my first port of call and the wiring a last resort
____________________
Laura - "And where did looks come into this and bugsy leave steven alone. You are not gods gift to women you may think you are but you're not."
Keith - "All the best"

[hmmmnz]

in my case it was the ht leads, and had the exact symptoms he described, it may not be his cause, but i think for the sake of £6 and a half hour of time its worth the small effort,

a sure fire way to see if your fans are on is get a bit of a4 paper and while the bike is on, slap it on the front of the rad, if the paper sucks to the rad, then fan is sucking,
under fast riding the zx shouldn't get much above 3/4 (75'c)
and really should sit somewhere between 1/2 and 3/4

let us know how you get on
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[Marah]

Yellowninja - My fan kicks in when the temp gets half way on the dial, no where near the red. It still gets really hot though on my commute to the city centre (I know not the best commuter) but never in the red and I can do a good 20-30mins 20-30mph speeds.

WTD - I had a problem with the 'on position' on my fuel tank which caused my bike sometimes not to start and run a bit rough I now leave it on reserve all the time no problems Need to be careful though Halfords sell a long plug tool thats a bit of a squeeze but it does fit.
____________________
Someone complimented me on my driving. They left a note on my windscreen, it said "Parking Fine"
Old Bikes -1990 Yamaha DT50MX > 1988 Kawasaki KMX125 > 1991 Kawasaki KMX125 > 1981 Yamaha XS250SE > 2000 Suzuki Bandit 600 > 1999 Kawasaki ZX7R Ninja
Bike - 1999 Suzuki Bandit 1200

[bish777]

[sickpup]

I think it could well be easier than everyone else here thinks.

Check the clearances on the inlet valves.

[Barry_M2]

Ignore all of the above.

The problem is with the vent from your fuel tank. Its blocked!

I've seen this soooo many time on the 7, and lots of others have had it too.

If it starts on the button first thing in the morning, but not when hot, even if left for just a couple of minutes, then its the fuel tank vent.

Also, if the spark plugs have not been changed for a while, change them.

The side stand switch was faulty, it would still start.
____________________
ZXR750R (M2) - For the road.
CBR1000 RR4 - For the track.
https://www.bikechatforums.com/profile.php?mode=viewprofile&u=4332

[sickpup]

[Barry_M2]

It has nothing to do with being warm or cold, its to do with the pressure in the tank. When the breather hose is blocked, the tank cannot release the build up of pressure fast enough. And the more pressure there is in the tank, the harder it is for fuel to flow out along the fuel line.

It might help if you reliease pressure by opening the fuel cap to release the pressure, but you need to do this before you kill the engine, or you'll still just get the same problem.

I've seen this loads of times on 7r's and this has been the fix in the majority of cases.


____________________
ZXR750R (M2) - For the road.
CBR1000 RR4 - For the track.
https://www.bikechatforums.com/profile.php?mode=viewprofile&u=4332

[sickpup]

[Barry_M2]

Your right, it doesn't. And I dont know either. But thats always been the fix of the problem in the past, clear out the blockage in the vent.

I had exactly the same problem with my 7. Stop for petrol after even just 5 miles, come back out and try to start after just a couple of minutes and it wouldnt' have it at all. The reason it ok after leaving it for long periods is that the tank will eventually release the pressure build up via the cap, or slowly past the blocked (or partially) pipe.
____________________
ZXR750R (M2) - For the road.
CBR1000 RR4 - For the track.
https://www.bikechatforums.com/profile.php?mode=viewprofile&u=4332

[Faldo]

Right then, I'm trying to add a switch to my 7R for the cooling fan as mentioned above.

I've taken the two wires that go on to a sensor on the radiator (On the left as sitting on bike) and joined them.

The fan should come on now right with ignition / engine on ?
____________________
Current: ZZR1400
Previous: ZXR 400 L9, ZX-7R P5, ZZR 400, ZX-7R P6, Bandit 600, GSXR 750 Slingshot, DRZ400, DR650, ZX10R C1H, ZXR 750 L1, ZXR 750 L3, '99 ZX7R P4, KTM 300 EXC, ZX-9R E1, TDM850

[Barry_M2]