Cold rear

[Cammo]

This is driving me crazy. What's the chances of both coils packing in cos I have one front cylinder firing and one rear. Checked for air leaks, changed plugs, checked wiring. It ticks over on full choke but dies when I rev it. The only thing left is the coils.

The coils will be fine - they fire the front and rear banks so you've proven that they work. Problems with them are rare.

I think you may have flooded and killed the plugs. Simple.

[TROUBLED OTTER]

Well I just carnt figure this one out.Bought new plugs and still exactlly the same.Only running on two cylinders.Checked butterflys and there all spot on.The only thing now I can think of is that theres an air leak or something.

[Drunkn Munky]

If im teaching you to suck eggs here then ignore me but are you starting it correctly? Ive never know any of my NC's to respond well to the throttle when cold, they would either cut out or sound very rough indeed leading me to think something is seriously a miss when infact there wasnt. Im also not alone when i say ive killed even 2 sets of plugs in a row trying to start a perfectly setup NC wrongly.

Not really much help but if stuck then start with the basics.

[arsey30]

How odd that at first the 2 rears were out, now it's the 2 right side.
Doubtful if it's ignition, especially coils.
Are the throttle slides clean and free, and lifting equally, and diaphragms sound.
Are you running with air box/filter on or off whilst testing, and yes, get motor hot first to test.

Do the 2 right side cylinders cut in if the motor is allowd to rev, even if only on choke, or are they completely dead?

Dave.

[TROUBLED OTTER]

I tried cleaning up all the earth contacts on the coils but it's the same. I managed to get three going for about 3 mins but then went back to two cylinders. I've only started it on full choke and it ticks over ok on two cylinders, then when it's warm I try to rev it and it trys to rev up to about 4 and then dies. The only thing I can think of is there's a air leak on the carbs somewhere. I'm going to take the carbs off again and check it all for the third time. Thanks for all the help guys I know it's hard to diagnose something what I'm trying to explain.

[TROUBLED OTTER]

Sorry, forgot to mention that I am running her with the airbox and filter fitted. Sliders and diaframs are fine, choke cable and sliders are fine. To be honest the bike is in really good shape, very clean. I took it all apart and reassembled her with no problems. Apart from the most important part, getting it to run, lol.

[TROUBLED OTTER]

Well, I had a friend look at the bike today and he thinks it's the crank sensor or the key has slipped inbetween. I was wondering if anyone has had the sensor fail. I checked the resistance between the contacts for the sensor and I'm getting a Reading off on side but nothing off the other . So this makes me think that it's the sensor. It's also fireing on diagnal cylinders which would point to the sensor on one side having no reading. What do you guys think or has anyone experianced a crank sensor failure?

[CMSMJ1]

You mean the pickup?? There will be a way to check...

[TROUBLED OTTER]

Pick up then. Please enlighten me on how to check it.

[CMSMJ1]

lol - I don't know...

But, as far as I do know.... there are two pickups/sensors mounted in the genny side cover - the 30 has 2, the 35 has 1.

These are the triggers for the sparks and I can imagine one of them has failed (as per your diagnosis)

So, have a look, see if you have a loose wire? I'll check my manuals an see if I can find a check for it....