79 KZ650 engine smoking

the spark seems to be fine on all plugs and their all within allowances. i did a comp test, it seems that the compression went up, then when i hit the throttle it went down lol. am i doing it wrong? or did i not wait long enough? i only had one plug out at a time, because it has to be running and i cant see it running on 2 cylenders haha

650ed theyre the NGKs i was suggested by my kawi dealer

yes you are doing it completly wrong call me i'm in the shop right dont do anything else until i explain a few things to you. 1-780-835-6687 i', just north of you about 500 km so i'm just a phone call away.

"650ed they're the NGKs i was suggested by my kawi dealer"

NGK's are fine, but which NGKs? In other words, they make B7ES, B8ES, B9ES plugs. I suggest if you're not using B7ES you should try a set to see if the sooting improves. Ed

oh im not 100% sure on that, ill check it out. those are colder plugs right?

thanks to timebomb i think ive got my issue figured out. i guess my sniffer isnt as good as i thought and there is gas in my oil coming out of my carb bowls. i did an oil change and came up with some pretty stinky black oil, and it no longer smokes but i can still smell unburnt fuel. old bike barn has carb kits for $22 each so ill be picking up those and perhaps a set of vacuum guages from Z1 unless perhaps i should just get the float valves from z1 if theyre all i need?

is there any other simple things i can do to help it out in the long run? i wouldnt mind getting a little more power to make it a little better on the hiway. ive got it sprocketed 17 front 41 rear right now and it just seems very gutless in my opinion. then again its an old bike right. getting rid of the air box means i need 4 39mm filters right? ive got good wires, theyre new still. i just figure i may aswell capitalize on making an order and buy a bunch of stuff at once. i also need new bars, mine are from a dirt bike it seems. do the grips come off easily or will i have to buy new ones and glue when i redo my bars?

im also looking at getting a set of short pipes for my bike. the ones i have now are really bulky and i wouldnt mind cleaning up the look of it some. i was looking at Campbell X-Pipes, anyone run those? even a short muffler would be nice, ive alerady got decent headers. ill be getting my seat redone when i get it all running nice again too.

Hotter plugs. Cold plugs are good for racing where engine temps are higher. Hot plugs are best for normal riding where engine temps are lower and soot doesn't burn off as easily. Ed

CTait wrote:

oh im not 100% sure on that, ill check it out. those are colder plugs right?

thanks to timebomb i think ive got my issue figured out. i guess my sniffer isnt as good as i thought and there is gas in my oil coming out of my carb bowls. i did an oil change and came up with some pretty stinky black oil, and it no longer smokes but i can still smell unburnt fuel. old bike barn has carb kits for $22 each so ill be picking up those and perhaps a set of vacuum guages from Z1 unless perhaps i should just get the float valves from z1 if theyre all i need?

is there any other simple things i can do to help it out in the long run? i wouldnt mind getting a little more power to make it a little better on the hiway. ive got it sprocketed 17 front 41 rear right now and it just seems very gutless in my opinion. then again its an old bike right. getting rid of the air box means i need 4 39mm filters right? ive got good wires, theyre new still. i just figure i may aswell capitalize on making an order and buy a bunch of stuff at once. i also need new bars, mine are from a dirt bike it seems. do the grips come off easily or will i have to buy new ones and glue when i redo my bars?

im also looking at getting a set of short pipes for my bike. the ones i have now are really bulky and i wouldnt mind cleaning up the look of it some. i was looking at Campbell X-Pipes, anyone run those? even a short muffler would be nice, ive alerady got decent headers. ill be getting my seat redone when i get it all running nice again too.

First things first (in hopes the lower end has not already suffered damage):

Keep the airbox.

Forget carb kits for the time being.

Carb cleaning alone often cures float valve leakage without needing new float valves or any other new carb parts.

Assure floatbowl overflow circuits are clean and clear of any obstruction, and that any overflow exits from the overflow tubes underneath the bike. Had the overflows been working properly, excess fuel into floatbowls should have exited underneath bike instead of rising up into carb throat and making its way into the crankcase.

Whatever parts as might eventually be needed are more than likely all available from Z1E.

With carbs, compression (valve clearances), spark quality, ignition timing, and fuel level, all up to snuff, may discover having plenty of power.

Regarding sparkplugs -- would use the normal NGK plug recommended by MaKaw (am guessing NGKB8ES).

Not the colder NGKB9ES used for racing or continuous high speed.

And not the hotter NGKB7ES sometimes used by riders always plonking around at lower rpm's who rarely enjoy taking a blast through the gears.

Good Luck!

Would also assure air filter is clean, or better yet NEW, and not blocked underneath the seat with a shop rag, gloves, or anything like that.

The KZ650, when running right, is a very powerful and fast bike. Where it's a first bike, running right, and still not fast enough to keep up with riding buddies, one or more of the pack is imo likely to soon depart the gene pool.

Good Luck!

Patton wrote: "Regarding sparkplugs -- would use the normal NGK plug recommended by MaKaw (am guessing NGKB8ES).
Not the colder NGKB9ES used for racing or continuous high speed. And not the hotter NGK B7ES sometimes used by riders always plonking around at lower rpm's who rarely enjoy taking a blast through the gears."

Not a bad guess, but still wrong . The Kawasaki Motorcycle Service Manual (July 25, 1979) states:

"Tests have shown the NGK B7ES, ND W22ES-U, or Champion N4, set to 0.7~0.8 mm gap to be the best plug for general use. If a plug of the wrong heat range is used, the electrodes may not be hot enough to keep all the carbon burned off...."

Earlier manuals did call for the NGK B8ES, but so many riders found these plugs to be too cold (including me) that Kawasaki revised their recommendation. I suspect that the earlier recommendation was based on factory track experience rather than street use. I ride very hard and originally used the colder plug, but having tried both I found the hotter plug to work noticeably better. Ed

ill keep the plugs in mind for sure. when cleaning the carbs should i remove them completly? or can i just spray cleaner into the air intake? ill clean out the overflow tubes when i do that too. my air filter is shot and the bike store is closed today. im stillg etting a bit of smoking and i can still smell the gas thats unburnt too. but its a lot better thats for sure.

lol well to be fair most of my buddies are on brand new liter bikes. so i do okay but theyre got the top end i dont. same with braking and i imagine cornering is a bit easier aswell. but! nothing some practise wont cure.

oh, whats .7-.8mm in a fraction? i bought a feeler guage but its all in thou. im hoping cambodian tire will have some plugs for me. off i go!

pull the carbs right off the engine and take the bowls off and remove your jets floats and needles and seats and spray carb cleaner thru every passage and oriffice then blow them out with compressed air. if you spray carb cleaner in it while it is running all your cleaning is the carb throat and what you need to clean is in side the carb it self also make sure air is passing thru all the jets as well. if you have problems getting the carb's off try using a heat gun on the boots and just push the back in side the air box when the heat softens them . it will make it easier to get the carbs out.

oh okay, sounds good. the overflow tubes are clean too. ill pull the carbs off as soon as i get time, friday i hope. i wont have to reset them once i take them apart will i? just make sure i put the jets in the same distance down?

Hey gang with a little knowledge I could be dangerous my bike used to run rich with the stock ngk b8es and could never get it nailed down it drove me nuts. anyway after rebuilding the carbs and checking testing everything main jets and pilot jets the problem all along was my pilot jet setting bought a colortune and set the carbs with it WOW so fast and so simple makes me wonder why I didn't try it before. the stock setting of 1 1/2 turns was just too rich for my bike. sorry for the rant maybe it will help with the carbs. bike runs so much smoother now. good luck