oil smells like gas and is black

I have a 75 kz400 I am trying to get up and running, just checked the oil which had been new last year. Mind you the bike has not been ridden yet, only test started about 40 or 50 times if not more.

The oil came out black and smelled of gasoline. I am guessing that i need to change the oil currently running 10w 40 or do a oil seal replacement. Any idea why it would be black? And any idea where i can get a set of oil seals for this bike, from what I remember they did a seal refresh after it came out.

I have vm30 mikuni carbs which i am trying to properly jet(impossible) and k&N filters with the original exhaust.

Check your carbs. Black is carbon. Could be from running rich or oil burning. Get it running, put some time on it then decide what to do with it.
Steve

How black is black?

Could be the engine has a lot of sludge from the previous owner and your new oil is starting to break that down. I'd put the bike on a 1000 mile oil change diet and see if that helps clear up the situation. Of course this assumes your carbs didn't overflow and dump gas in the crankcase. Better check the oil level to judge that.

BTW, be sure to use either motorcycle oil or diesel engine oil. Both of these options are better than car oil (in case you didn't know).

msardes wrote: I have a 75 kz400 I am trying to get up and running, just checked the oil which had been new last year. Mind you the bike has not been ridden yet, only test started about 40 or 50 times if not more.

40 or 50 cold dry starts are hard on an engine.

msardes wrote: The oil came out black and smelled of gasoline. I am guessing that i need to change the oil currently running 10w 40 or do a oil seal replacement. {/quote]

Gasoline smell most likely means your float valves are not seating and the carbs are draining fuel into the engine. Yes, change the oil and make sure you close the fuel petcock, when not running it, to minimize the problem until you sort it out.
Oil seal replacement? Why?

msardes wrote: Any idea why it would be black?

Dirty engines will discolor new oil quickly, particularly, if the new oil is synthetic. Color of the oil itself may mean nothing.

msardes wrote: And any idea where i can get a set of oil seals for this bike, from what I remember they did a seal refresh after it came out.

Seal refresh? Did someone charge you for that?

msardes wrote: I have vm30 mikuni carbs which i am trying to properly jet(impossible) and k&N filters with the original exhaust.

Are you saying that you've fitted K&N pod filters and are now having problems with jetting? Do you still have the stock air box?
Keep us appraised of your progress.
Best of luck.
Bill

Gasoline smell most likely means your float valves are not seating and the carbs are draining fuel into the engine. Yes, change the oil and make sure you close the fuel petcock, when not running it, to minimize the problem until you sort it out.
Oil seal replacement? Why?

I had read that if the oil smells like gas that gas could be penetrating through the oil seals. Probably BS

Dirty engines will discolor new oil quickly, particularly, if the new oil is synthetic. Color of the oil itself may mean nothing.
Oil is 10w-40 non synthetic


Seal refresh? Did someone charge you for that?

No, i had read that shortly after this model was released they came out with a service kit that would replace all of the oil seals with better ones.

Are you saying that you've fitted K&N pod filters and are now having problems with jetting? Do you still have the stock air box?

Bought the bike without the stock airbiox,

Bike is a:
1975 KZ400D
Mikuni VM30 Carbs (Working on jetting and failing)
Emgo K&N type air filters
Stock Exhaust

Bike was purchased with 4000 or so original miles, compression is very good.

BTW anyone have any advice on Jetting these carbs, I have contacted speed moto co but they would give out their specs for their VM30 carbs for the kz400



Thanks for all the help.
Michael

Try here.
Steve
jetsrus.com/carb_rebuild_kit/carb_rebuil...kawasaki_street.html

Well, hope that 10W-40 you are using is not automotive oil. If it is you might want to dump it in 500 miles or so and move to diesel oil like Shell Rotella (15W-40 or 5W-40 synthetic).

Good luck with the jetting. I always make sure to stay 100% stock with the carbs/airbox/exhaust because I HATE F'ing around with jetting. Way too much work.

Below is what I'm running on my VM30s on my 76 KZ400. That should get you in the ballpark. Another guy was doing the same thing at the same time I was (his was a 75) and he ran the 3.0 slides and said it helped get rid of some part throttle "burble" that he was having. The 3.0 slides would not work for me at all though. I'm using big K&N filters and some free-flowing aftermarket mufflers so YMMV. I'd recommend not using the Emgo filters and go with K&N or Uni filters.

Main Jet: #230,
pilot jet: VM22/210 #25 or #30 cannot remember off the top of my head,
Throttle valve cutaway (slide): 2.5
jet needle: #6F5 on #4, (STOCK Needle, 1 Clip Richer)
Air Screw: 1.75 turns out
needle jet: #159 P-5, (STOCK)
air jet: BS30/97 2.0, (STOCK)
needle valve set: VM34/39 3.3, (STOCK)
float height: 22-24mm (STOCK)