1980 kz440 Fuel leaking out of exhaust and foggy oil

Hello, I’ve had this 1980 kz440LTD for many years occasionally working on it but I haven’t got it running right yet. I finally made an account on the forum because I thought I’d need as much insight as i can get before I keep running this thing and damage something. So I just rebuilt the engine because the cylinder walls were gouged/scratched (mostly right cylinder). I deglazed the walls until I couldn’t see any gouges then I put new pistons and rings. Looking back now I wish I had sleeved them to add longevity. I took the engine head to a shop to get a valve job and to recut the seats because I had swapped one valve guide that I damaged. They checked compression and all. This was my first rebuild and it was a learning experience.. but I feel decent about it and thought it should at least run better than before. After putting it all back together I my compression read about 130psi and the spec from the manual is between 109psi-156psi. I won’t go too much into the engine rebuild unless someone is thinking that’s where my issue is.

Upon my first start up I did miss some things and it ran badly as I saw fuel leaking out of muffler and oil leaking into crankcase. I Took the carbs apart and my main jet was entirely unscrewed in the float bowl. So I got that corrected and cleaned the carbs good. Another thing was the intake boots were not clamped so I got those on tight. Lastly I checked my valve clearance and I had the exhaust valves adjusted way too much so I corrected that. Then I also replaced contact breaker and set timing with a light. I thought all this would fix things, but I still had the gas leak out the exhaust and oil in case after trying doing all that. It ran better, but still would get bad as it warmed up and seemed to rapidly accelerate without me touching the throttle until I had to just kill it. I hear often times it is the float needle that can cause too much gas/uncombusted gas. But it is a practically new needle and I inspected mine.

Here are some things I’ve done since my last time running the bike.
–improved exhaust seal where it mounts to engine because when I was mounting the pipes onto the header one stud broke off so I think it wasn’t sealed enough. I found out I could replace the stud so I will be tight and against the gasket next time I start it.
–I checked my float bowl height and the right side bowl was a little low. So I adjusted the float clip and now its fills up more.
–I checked the spark and it is blue. I thought the spark was weak but maybe it’s normal and at least I could see it without turning the lights off. (Also brand new ignition coils and relay starter)
–I replaced the needle on my carburetor slide because the last one looked bent.
–double checked my valve clearance and I did add slightly more clearance in the exhaust valves because it was a little hard to slide the gauge in there. But it was close.

All the symptoms of how its running seem carb related to me because it seems like it’s just running rich unless something else is causing the gas to not be get burned all the way. 

The only thing I can think of is that maybe the jets in my carbs were supposed to be for pod air filters, because I got the bike from someone who new nothing about the history and it didn’t come with the stock airbox or air filter so it’s possible it was rejetted for pods and that throwing it off. I have the stock airbox and a 3D printed air filter that matches stock. Here are the jet sizes I have in my bike in case anyone knows what the size stock is.
Primary main jet- 62
Secondary main jet- 88
Pilot jet- 35

Any insight is much appreciated. Thank you

From this table it sounds like you have the stock sizes of the jets. (for use with air box)


If fuel is indeed leaking out of the exhaust ( or is it just condensation in the pipe that you are seeing?) and it appears that fuel is in the crankcase then it would to me appear that fuel is not being stopped by the float valve or the level is way too high. If that is the case I would suggest to drain the oil, solve the overflow issue and then put new oil in and try to start it again.

I would also ask what is the voltage to the coils, it needs to be close the full battery voltage, if not then the spark may not be sufficient to burn off the fuel and some gets pushed into the exhaust pipes.

Thanks for the advice and the reference table. I was pretty sure I checked the fluid that was leaking out by touching and smelling. I checked my float valve and it looks fine and it’s new. I have tried to clean some brown spots of the brass sleeve guide for the float valve with carb cleaner and qu-tip, so and it looked the same after, so I think that wasn’t the problem. I also checked my float bowl level with a clear tube and it was correct and assume that would be off if the needle wasn’t working right.That’s a good point to test my ignition coils. I  actually tested my ignition coils with a multimeter and got “0” ohms when I tested with spark plug boots on, but I got the right reading with boots off touching direct to my leads. I replaced the boots and got about 22 ohms. I’m hoping the bad boot was the cause of gas not igniting and hopefully led to my fuel going through to exhaust pipes and crankcase. I’m going to hold off on starting the bike until I’m sure this was the cause. I tested the voltage from right after my starter relay and it was the same as my battery (12.7). But when I check voltage at the  ignition coil connection it was at 10.92 V. I read that in some cases that is reasonable voltage drop, but i don’t know about this bike specifically. So right now I’m trying to figure out if that’s normal for my bike or if it is a problem with my wires/connections. 

Izzyrider1015 wrote:

Thanks for the advice and the reference table. I was pretty sure I checked the fluid that was leaking out by touching and smelling. I checked my float valve and it looks fine and it’s new. I have tried to clean some brown spots of the brass sleeve guide for the float valve with carb cleaner and qu-tip, so and it looked the same after, so I think that wasn’t the problem. I also checked my float bowl level with a clear tube and it was correct and assume that would be off if the needle wasn’t working right.That’s a good point to test my ignition coils. I  actually tested my ignition coils with a multimeter and got “0” ohms when I tested with spark plug boots on, but I got the right reading with boots off touching direct to my leads. I replaced the boots and got about 22 ohms. I’m hoping the bad boot was the cause of gas not igniting and hopefully led to my fuel going through to exhaust pipes and crankcase. I’m going to hold off on starting the bike until I’m sure this was the cause. I tested the voltage from right after my starter relay and it was the same as my battery (12.7). But when I check voltage at the  ignition coil connection it was at 10.92 V. I read that in some cases that is reasonable voltage drop, but i don’t know about this bike specifically. So right now I’m trying to figure out if that’s normal for my bike or if it is a problem with my wires/connections. 

That is far from reasonable  !! you should have no more than 0.5v drop from battery to consumer. Also your coil readings should be between 2-4 ohms on the primary side and approx 15k ohms on the secondary (check the manual for specific spec for your bike) there is a link in my signature to the electrical fault finding guide I wrote, check out resistance faults

Thanks for the information, Wookie. The primary test was right on 4ohms, and the secondary was 12.9 ohms on the coil leads with is in spec. but the boots add about 5 ohms each because of resistors or something like that, so with boots it’s 22.9 ohms.

I went to the Forums FAQs and saw that you wrote out The Electrical Fault Finding Guide, but the link wouldn’t work for me and just say not found. It would be super helpful to go through it so just let me know if you know how I could view that still!
Thanks!

I went through the obvious things so far like fuse connections and ignition switch, but I just need some time to dive into it!

I do not mean to speak for Wookie, but you can find the doc in the filebase here    kzrider.com/filebase-alias/category/28-g...l-electrical?start=5

Keep in mind that you have to be logged on to the forum to have rights to the filebase section