Zephyr750 running issues.

[BravoCharlie]

Hi guys,

Hope we are well, and sorry for the wall of text below...

I'm having some trouble with my bike. To give you a backstory, i got the bike a few weeks ago. When i got it, she wouldnt run properly and would cut out. It seemed as though it was a fuelling issue and eventually the bike would only run on 2 cylinders (1&2 would run so not a coil). Took it to the mechanic, we changed the fuel filter and fuel, and it ran fine with no issues. I never used it last week as i was working 7 days and 14 hour shifts between 2 jobs, so it made sense to take the cage. It sat in the rain pretty much all week as the current cover is too small.

Fast forward to monday, im off this week and fancied a run. I got 5 minutes down the road and it cut out. Managed to nurse it home, but just. Today i checked and i think maybe the seal on the fuel cap has gone and let water in. Completely drain the tank and carbs, new fuel in and she sounds great again. Took it a 20 minute blast locally, sounded fine and ran fine. One hour later i go to use it and it's the same story, 2 cylinders,dying on me, high revs to get it home again. Any thoughts?


Sorry for the long text and any spelling issues, I'm typing on my phone!

Cheers,

Barry
____________________
Current: Kawasaki ZL600 Eliminator
Past: Suzuki GZ125, Kawasaki GT550, Kawasaki GPX600R, Honda vrx400,Kawasaki Zephyr 750, Suzuki SV650 K5
Dream as if you'll live forever, live as if you'll die today.

[Casper]

Could be dying HT leads or coil that brake up when hot. I would get the carbs out first for a proper clean before spending money. Is the tank breather free. Is the fuel filter inside the tank clean.

BTW you can call a car a car its also one keystroke less.

[temeluchus]

Float needles.
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Some shite cruiser. Now with guns and FREEDOM!

[hmmmnz]

im just gunna put it out there, valve clearances..
i had all sorts of crazy things happen on my zxr when the clearances had tightened up,


wouldnt start, would start, ran great, ran l;ike shit,
would randomly drop a cylinder,

i thougght it was carbs, electrics, and spent ages chasing my tail,
worth having a check if you have the tank off and are checking the carbs anyway
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[BravoCharlie]

Thanks for the input guys.

So the general idea is to start at the carbs. I've never done any work on the carbs or valves before - is it a tricky job to do?

Cheers,

Barry
____________________
Current: Kawasaki ZL600 Eliminator
Past: Suzuki GZ125, Kawasaki GT550, Kawasaki GPX600R, Honda vrx400,Kawasaki Zephyr 750, Suzuki SV650 K5
Dream as if you'll live forever, live as if you'll die today.

[Robby]

Follow the Haynes manual, ask questions on here as you go. Expect it to take a while. Expect to end up spending some money, the point of the carb cleaning process is to inspect bits for wear and replace what needs replacing.

Getting the carbs back onto the bike will be a pain in the arse.

The problem may end up being something else altogether.

[RhynoCZ]

There shall be no fuel filters on GPz/Zephyr engines, also when this happens again, try to run the fuel tap on PRI, if it gets better, the tap is faulty.
____________________
'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[BravoCharlie]

[bikenut]

check on cmsnl as there may be small filters just above the float needle valves, they may be blocked/blockage etc and I bet there is a filter on the tap, in the tank.

If yours has a flush fitting fuel cap then there will be a drain to let the water out that will fill the gap tween cap and tank.

Make a simple cover to cover the fuel cap or the whole bike if stored outside.

hopefully the cap drain which passes thr the tank is not leaking........somewhere near the top...........any fuel coming out of the cap drain? or is it blocked with crap??
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nuts about bikes

[RhynoCZ]

I also had the same problem and as I have been told, on the GPz550 forum, every air cooled Kawasaki in-line four has to have no restrictions in the fuel line. I bought my GPz with a fuel filter, and it was very restrictive, as I found out later. It caused fuel starvation and dying after a couple of minutes of ride at faster pace. The PRI helped to force the fuel through a bit, but it was not the solution, also the PRI only worked with at least 1/2 of the tank of fuel. I tossed that fuel filter away and got a new fuel line = worker alright again.

Also your problem might be in the tank breather, that's also a common problem of the 80's GPz's. Cleaning shall be enough. The last thing that could go wrong, speaking of fuel starvation is your float valves and fuel tap.

Side thought: fuel filters are not a must. If you've got clean tank. If the filter was not on the bike when it came out of the factory, you're might gonna face the problem I had with my GPz = insuficient fuel flow.
____________________
'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[Casper]

[Casper]

As for cleaning your carbs out they are quite easy. Ask Dan

https://www.dansmc.com/mc_repaircourse.htm

and try and find a youtube video. I was lucky as the video was for my model of bike.

[Robby]

Thinking about it, fuel filter could cause problems. I'm not sure of the reason, but I have seen inline fuel filters causing problems on vacuum fuel taps before, possibly something to do with the air bubble in the filter stopping the diaphragm in the fuel tap from doing its thing properly.

[BravoCharlie]

Guys, thanks for all the input so far, genuinely appreciate it.

To give you an idea, this is the fuel filter https://i1263.photobucket.com/albums/ii639/bravocharlie1/20140801_185516_zpskumrzisn.jpg

That's the old one but was switched for the exact same. I now guess they shouldn't be there and if that's the case i'm going to.get a fuel hose long enough to do without one, and take it from there. I'll probably still get the carbs checked out for peace of mind too!
____________________
Current: Kawasaki ZL600 Eliminator
Past: Suzuki GZ125, Kawasaki GT550, Kawasaki GPX600R, Honda vrx400,Kawasaki Zephyr 750, Suzuki SV650 K5
Dream as if you'll live forever, live as if you'll die today.

[RhynoCZ]

That does not look like something Kawasaki would put there.
____________________
'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor