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

get the bike running, spray wd40 around the intake boots and listen for a change in rpm. then do it again when it is hot. if the rpm changes u have an air leak and a resolution to the biggest part of the problem.

Both carb holder (intake boot) and airbox hose rubber are brand new (less than 4 hours of use), i will check later for carb leak but it is improbable (rpm would hang or idle high)

Increase to these settings today:

From:

110 main
40 pilot

To:

120 main
42.5 pilot

At first because i didn't have any main jets in between, i was like no way it would run without bogging (too rich) at WOT...

Heck engine pull even better (didn't have flat spot previously too!) and now much more torque!

Idle still want to stall at stop but its less frequent but still happens... maybe we are getting closer to the fix!

Other thing ... from #110 to #120 main i though it would be richer but when i pulled the plug they (4) are still (core) BONEWHITE! ????

Is 110 to 120 a big increase? for me it look like yes but judging but bonewhite plugs i should jump to 150 main jet??????

Any expert on the subject?

I will wait for explanation before buying anymore main jets!

(don't know which to buy anymore....should i buy by 10 increment or 20 , 30 , 50 or should i jump to 200# main jet???)


thank you very much !

have a nice day!
laurent

EDIT: engine jugs dropped from 350-370F to 290-310F after the same ride... maybe has something to do with the richer jets...

ELCouz wrote:

What country are you in? A lot ofthe gasoline in the USA has so much alcohol in it these days that the plugs don't color up like they used to with the same jetting.

Canada... i'm using premium fuel 91 AKI or 94 RON (which don't have ethanol like regular fuel)

Lift the needle 2 clip positions if it's adjustable. If not, shim it 2mm richer with tiny washers.

Yes it is adjustable (canadian version) but i'm already a the 2nd position from bottom .. time for bigger main jets

I think I'm lean on the low cruise .. idle is ok (after 4 turns out [too much i think]) but if I'm too lean on cruise engine might overheat and upset idle mixture right?

Currently IIRC, i'm running on #117.5 main jets and #40 pilots ... i will try with 120 main and 42.5 pilots

If my memory serve me correctly, pilot jet are for cruise and idle...

Obviously not running on stock pipes :lol: but no pods :sick:



BTW larry, why don't you move out of USA and go here in Canada ... we need more KZ expert up in here :laugh:
Also we have snow its good for you i promise

fisrt u said u had 117.5 mains now u say u have 110's ????

the wd40 air leak test will help u determine if it is going lean when it gets hot. u said it acts up when it gets hot. if u changed the mains and the pilot at the same time, how do u know it wasnt the pilot that helpd and not the main? the only way the mains will afect the mid range throttle openings is if the main was drasticaly undersized. this would starve the miderange .
what is the stock main and pilot size for this bike ?

fisrt u said u had 117.5 mains now u say u have 110'

I wasn't sure being 6 months since last time I've opened them,

i thought it was 117.5# because of my last year purchase history with z1 enterprises.

Kept 110# because 117.5 was too rich.

But now i've had a big bore (810cc kit, because of a scratched cylinder)and new stuff around carbs.
Carb are sensitive to change... why you change so many things at the same time would you say.. because they were in bad shape! No point to tune carbs when old stuff leaks or are hard as rock!

if u changed the mains and the pilot at the same time

Pilot were too small .... had to make 4-5 turn out before engine could run smoothly checked with colortune spark plug

Main jets looked too lean, spark plug all 4 where extremely white( even with the coldest plug installed (BR9EIX)... done WOT and killed the engine and read the spark plugs

what is the stock main and pilot size for this bike ?

Stock:
#110 main
#37.5 pilot
#4 position clip from top (Canadian model, US one is leaner 3rd pos)

Now 120 main, 42.5 pilot are installed today

Remember i do have a racing pipe (no baffle) and oil soaked foam air filter replace to a less restrictive K&N air filter in the airbox... no pods..

Never had stock pipes... i think PO did install the pipe when he bought it in 1982. He never changed the jets thought !

I've bought a laser tachometer to check the idle rpm... thetachometer on my bike, i don't trust it... look not so precise

regards,
laurent

u can also use an unlit butane torch instead of WD 40 remember stooges thats a UNLIT torch :laugh:

good to hear u are making progress.
at the begining u had trouble when it got hot.
so were are u now. how does it feel? what happens when its hot now ?

good to hear u are making progress.
at the begining u had trouble when it got hot.
so were are u now. how does it feel? what happens when its hot now ?

When hot, it still want to die at red light but its less hardcore (one throttle blip every 2-3 minutes before it was every 10 seconds i needed to give some gas)

still the same problem but less intense... maybe im the right way i will order 130 jets to try


thank you very much

regards,
laurent

sounds good .
keep adding bigger mains, untill it feels bad on top. then back up a bit. then do the same with the needle. then u can play with the pilots.
hopefully this will cool her down a bit.

130 sounds pretty big , maybe start with 125's ? your call.
good luck

130 sounds pretty big , maybe start with 125's ? your call.
good luck

Good idea!

Here's my buy list:



KL18-4383-1
Mikuni Large Round Main Jet #127.5
Sku:
4 $1.74





KL18-4384-1
Mikuni Large Round Main Jet #130
Sku:
4 $1.74





KL18-4385-1
Mikuni Large Round Main Jet #132.5
Sku:
4 $1.68





KL18-4386-1
Mikuni Large Round Main Jet #135
Sku:
4 $1.74





KL18-4387-1
Mikuni Large Round Main Jet #137.5
Sku:
4 $1.74





KL18-4388-1
Mikuni Large Round Main Jet #140
Sku:
4 $1.52


Should be enough!

Already have 110,120,122.5,125

After that i don't know where to purchase bigger jet!

z1 stop at 145!

regards,
laurent

Why not throw the 125's in then before u order more. u may not need more.

when u where running the 110's the mid section (needle) was obviously starving, thus caused the overheating. a way to test to see if the mid is starving is to remove the mains altogether, and retest.
the needle restrict the flow so it should run fine until u get near 3/4 throttle.
if it runs better, u know the main u had in there before was still too small.

Why not throw the 125's in then before u order more. u may not need more.

Z1 Enterprises made a mistake last purchase.

They shipped me 3x 125 main large round jet and a small round one...
So i've ordered 1x 125 main round large again while paying 35$ for shipping for just a little jet why not buy other range just in case!

Can't wait to try new jets!

regards,
laurent

OH, that sucks.
i hope they get it right this time.
they have been very good to me. i have enjoyed doing buisiness with them.
Jeff really knows his kawi's.

People are laughing at me when i mention VAPOR LOCK seriously i do get this thing when it want to stall at stop the fuel tubing have no fuel inside! The tubing and the petcock go around 70C (158F) the fuel is vaporizing!

What can i do to isolate the engine heat from gas line ? The petcock is very close to the valve cover which get hot too!

If i could i would put the gas tank on my back! :woohoo:

Should i drill and relocate the petcock at the farthest possible from the engine ????


Looking for clues !

Many thanks guys!

One step closer to perfection!

best regards,
laurent