My Kwaka's not happy

[Omega1]

Hi Everyone,

Just hoping someone can help me,my ZX7R has started running rough it starts ok warms up ok but when you ride away it feels like its running on three cylinders with half power..Now I have read that ZX7,s are prone to Carb icing (apparently this happens with ZX7s frequently in the UK) and with the cold weather (crap)we are getting here in Wellington I thought it might be that?.I went for a ride yesterday and it was terrible.The temperature needle hardly moved and she stuttered and was running rough the whole time.The ride before that the bike cleared itself after 5mins and was ok.The bike hasnt been used much lately and is garaged. It could be electrical I,m not sure.I just thought I would ask before I ring my mechanic so if theres any kwaka experts out there.....Help!!!

[Blakamin]

Have you pulled your plugs and cleaned them recently?

[vifferman]

Hi Everyone,

Just hoping someone can help me,my ZX7R has started running rough it starts ok warms up ok but when you ride away it feels like its running on three cylinders with half power..Now I have read that ZX7,s are prone to Carb icing (apparently this happens with ZX7s frequently in the UK) and with the cold weather (crap)we are getting here in Wellington I thought it might be that?.I've experienced carb icing (on the VF500 I used to have), and it takes quite a while for that to start happening, but does feel like what you've described here. It clears up if you're riding at lower revs and/or if you stop for a while.
I think it's more likely to be plugs as blakamin said, or crap in the carbs than icing.

[Motu]

Sounds like your thermostat is stuck open,if it has one,dunno what those letters and numbers mean in real life.

[FROSTY]

drain the carbs too--might be worth a crack

[Madmax]

had the same proBlem on a 92 750J2 was a fault with coils
put some dydas on it worked fine
MaX

[F5 Dave]

See if you can locate which pot it not firing (if any). Start from cold & just idle, don’t rev it & put your hand on the headers. They should get too hot to touch pretty soon. Any that lag indicate an issue with that cylinder.

If it has been sitting, Take the carbs out & blow through the pilot jets (don’t poke wire through). Change the plugs & put a meter over the sparkplug caps to see that the resistance is not too high (Dicky Smitty have cheapo meters for playmoney). Any that are significantly too high – replace.

While you are about it pull the thermostat out & check it, I had a thread some months back in this section if you did a search, but I believe that thermostats are often rated too low to cope with all markets. Try to get one about 88 deg, I found one from a car & just had to drill one bleed hole like the original. Heats up now. This may help your carb icing problem to some extent.

The coolant should be changed every couple of years or there is a very real chance that the corrosion will damage the head seal on an older bike, so you needed to drain the fluid anyway.

[Omega1]

Thanks very much for the replies,I have just checked with the Mechanic and the problem was a dud spark plug Whew! They have replaced all the plugs and she is running well now.

[LB]

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.Hi Omega1 - good to hear from you. :) :) :) Glad you've got the problem sorted. Do I detect a new motorcycle in the Omega1 gargre? (just a stab in the dark, the "my/favourite bike" gave me a slight clue......!!

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[Omega1]

Hi Lynda,
I was waiting for a comment and yes I have purchased a Harley.Its sitting in the garage next to the ZX7R waiting for the sun to come out.To say riding it is a big change is an understatement but its lots of fun (and lots of chrome to polish when its raining).I think Mark and Steve are still getting over the shock,Dont worry after reading the threads about Harley riders not waving I intend to keep waving at everyone! I hope to catch up with you and Hamish up the top of the hill soon.
Regards Neville