[SOLVED]Engine break-in....stalling...overheating?

According to the kaw website, the mechanical advancer on your bike is only used on 750's. The 550 one will likely bolt on, but the advance curve may be different.

I'm not too familiar with those carbs, but a ripped diaphragm won't affect manifold vacuum at idle, and will increse it when you open the throttle. Also a ripped diaphragm really shouldn't affect idle in any other way either, as far as I know. I've only seen ripped diaphragms affect off-idle response.

It did occur to me that there may be some remote chance the oscillating may be enricher-circuit related, but it was just a passing thought. You could try to gently push down on the enricher rods while it's idling to see if it changes anything, that is, if it has plunger rods activated by the choke lever.

Dumb question, I know, but are the vacuum caps on the carb holders? (there was a guy on this site a while back who didn't know they were needed) Ed

There is no dumb question!

They are all installed...otherwise bike won't run without them... mine just stall... brand new too!

According to the kaw website, the mechanical advancer on your bike is only used on 750's. The 550 one will likely bolt on, but the advance curve may be different.

Maybe weight are different, anyway i will try with the rubber band.

As for the timing light, at any rpm it should flash either at 1-4 timing mark or 2-3 depend which spark plug I've clamp on ?

Could i change the carb rack to let says a BS34 from a GSX ?

What type of carb fit with the KZ750 intake spacing?

That would be in worse case scenario thought!


have a nice ride guys!

best regards,
laurent

ELCouz wrote: Thanks loud for the reply !

One more question... when in traffic... the idle is around 1200 rpm then after few seconds if i don't touch the throttle it will drop to 800-900 rpm and start to oscilliate to 800 - 1200 - 800 in a 5 seconds interval... if i give a tiny squeeze (1/32th) on the throttle it will go to normal idle (around 1200 rpm again could be 1100 my tach look unprecise) then after 20-30 secs drop again to 800 ... if i raise my idle with the screw to 1100-1200 when its at 800 rpm when i move the idle would be at 1500 rpm (way too high)...

ur throttle cable is binding, lube it


Highly unlikely, since its doing it without throttle cable installed but since i'm desperate ... oh yeah i'm lubing it!

thanks guys!!!!

regards,
laurent

sooo ur not using a throttle cable when u ride, :dry: :blink:

Perhaps carb return spring has wilted or isn't oem.

Good Fortune!

Patton wrote: Perhaps carb return spring has wilted or isn't oem.

Good Fortune!

That happens when you forget to water them :silly:

Oh manhood flower,
Where art thou spring,
Wilt not she pled,
Stand tall and sing.

Good Fortune!

cavanaughracing wrote:

Patton wrote: Perhaps carb return spring has wilted or isn't oem.

Good Fortune!

That happens when you forget to water them :silly:

well piss on it, :woohoo: no really

the reason I mentioned throttle cable is I routed mine under the tank and secured it with a tie wrap, I had pulled the tie wrap to tight and the same thing was happening to me.
on my other bike I had to lube the cable to solve a similar issue
but I waiting to hear an answer, riding with no throttle cable ????:laugh:

but I waiting to hear an answer, riding with no throttle cable ????

Yeah i do it all the time :lol: , hand under the seat.... here we go! No need for stinking throttle cable ...

Most of the time when troubleshooting, carb are not connected to throttle because i know i will need to remove them again (adjust fuel level or jets)... idle problem appear either without the throttle cable or with it!

Perhaps carb return spring has wilted or isn't oem.

One thing i'm sure , its the damn return spring is stiff... snapped a finger once when quickly released the throttle by hand!

Btw, received my digital IR tachometer today, gonna check tomorrow if idle is set right!

FSM specify 1000-1100 RPM idle... but if i'm not able to get it run smoothly at these speed could i go a little bit higher (1200 RPM)?

regards,
laurent

If the ignition advancer gets ruled out, the next thing that comes to mind which may go into an oscillation , is the carb slides.

If you have the throttle opened up far enough at idle, farthter than normal that is, maybe due to a mixture issue or some other issue, it may be openend far enough that the slides are right at the point of lifting off the bottom of their travel. So they start to creep up and the idle increases. But when they lift up slightly, the mixture gets too rich, so the idle starts to drop, this drops the slides back down. Then the mixture is stronger again and the cycle repeats.

You could try to put some weights in the slides, or maybe block the slide hole (the hole at the bottom of the slide) so they will not lift off at all. Then see if the idle at least stays steady.

If the ignition advancer gets ruled out, the next thing that comes to mind which may go into an oscillation , is the carb slides.

If you have the throttle opened up far enough at idle, farthter than normal that is, maybe due to a mixture issue or some other issue, it may be openend far enough that the slides are right at the point of lifting off the bottom of their travel. So they start to creep up and the idle increases. But when they lift up slightly, the mixture gets too rich, so the idle starts to drop, this drops the slides back down. Then the mixture is stronger again and the cycle repeats.

You could try to put some weights in the slides, or maybe block the slide hole (the hole at the bottom of the slide) so they will not lift off at all. Then see if the idle at least stays steady.

I will go in a more drastically manner... buying new rack of carbs!!!

A lot of parts locally but.... will ZX750 83-85 carbs will fit ?

Could i use a gpz 1100 EFI ... what will fit ? Also which other brand use Mikuni BS34 ? suzuki ? yamaha, honda ?

GPZ 900, lots of parts for this too!

This could give me more choice in my searches!

Many thanks!

regards,
laurent

EDIT:

My current carbs looks like new and very clean but in fact they may hide something (maybe cracked inside) ... creating a little air leak when hot... better be sure with other carb!

kzrider.com/forum/3-carburetor/232899-82...50-replacement-carbs

They were stock carbs on most of the KZ1000 and KZ1100 bikes from 1981 on, as well as several other models.

Can someone confirm that KZ1000-1100 have bs34 ?

Also i've read in the forum that 83-85 ZX750 have push-pull BS34 carbs ?

I just want to be sure before buying... i have only one cable (pull)

have a nice day,
laurent

GPZ 1100 1995 .. looks like Mikuni BS36... don't know the carb spacing would be great if it could fit!

regards,
laurent