Good morning all.

I am new to this forum and i urgently need help with my zzr 400.
I have a '95 zzr 400n and ive been having problems with the bike running rich and not pulling properly at mid revs. Between 2000-5500 rpm the bike 'misses' or bogging occurs. At high revs it ran fine.

Last week it i suddenly had problems starting it and when it started it wouldn't idle or rev up. After a few minutes of push starting it it would idle slightly at full throttle and very slowly start to pick up revs. I then proceeded to change the plugs and check the plug wires. And it seemed the problem went away. Bike started first time (engine was still warm). The next morning it wouldnt start at all and ever since ive been strugling to start it. I checked all the plugs for spark and the coils. Removed the carbs and cleaded it thoroughly. (the idle jets were slightly blocked). After cleaning the carbs and installing it again with the air/fuel mixture screw turned 2 1/2 turns out. I tried to start it again so i could balance it. But still to no avail. I am lost and boggled at this as the bike was running fine besides for it running rich. I bought gauges to sync it but my float heights were all over the show and the dials on the gauges was moving erratically. This also influenced my decision to remove the carbs and reset it.

Does anybody have any advice on how to at least get the bike started or where else to start trouble shooting. I need the bike to get to work 40kms away and im desperate.

Any opinions would be appreciated

 

I say go back to the basics. After totally soaking and cleaning of the carbs,,,,,,
during install, how did the CV diaphrams look? Are they seated properly, any cracks, etc. The needle height, what level? What is the float height set at? I would recommend replacing seats and float needles. 2 1/2 turn out is a good baseline, yes. The plugs are prolly dirty now and need cleaned. I normally find that the main jet holder is the one that plugs up on me.

Don't forget to look at your fuel screen/filters.

 

Thanks for the reply Dragone.
float Height is set at 13mm and i started with the fuel/air mixture screw at 2 1/4 and work my way to 3 and then back to 1 1/2 but still nothing. I've cleaned the plugs changed plug wires and checked that the coils and plugs spark.
i checked the diaphrams. float needles look fine. there's not even a mark or any sort of damage or or signs of wear on the needles. the needle height is still standard on the cv, i haven't shimmed it up or anything.

Main jet holders? would that be the inside of where the main jet screws into? sorry if i sound a bit thick.. im very clued up on car engines and smaller motorcycle engines. this is my first bigger motorcycle I've owned. fuel/screen filters? where would i find that? or is that the in-line fuel filter just before the pump?

 

I am not a mechanic, but what I meant was the emulsification jets get plugged. According to the parts fiche on your bike, it was the main jet holder.

The petcock screen can get plugged from the tank. Not sure if yours has an inline fuel filter or not aftermarket.

[QUOTEi checked the diaphrams. float needles look fine. there's not even a mark or any sort of damage or or signs of wear on the needles. the needle height is still standard on the cv, i haven't shimmed it up or anything.
][/QUOTE]

hahaha, you have been around the block a time or two. Good to see that someone has done or even knows tidbits like that.

 

Thanks Dragone

Im sitting with a new problem!!! I've replaced the spark plugs and managed to get the bike to start, synced the carbs and took it for a test drive. but not long and then my plugs died again. i have a set of plugs that are 2 days old and a brand new set that are both dead or not sparking correctly.

When i removed the plugs it was quite black and sparking from the porcelain ti the thread and not between the electrode.

Does anyone have any idea on what might be causing this????? i have to replace plugs everYtime i get the bike started it kills my plugs..

 

What plugs are you running?

I would stay with NGK personally.

 

to me it sounds like valve clearance, these bike has shims on top of the valve spring and by age the valves get worn and the valve clearance tightens so you have to do valve clearance. Hope this helps.