78 KZ650 Project needs serious TLC

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Must locate the crack. It's usually easy to see. Or perhaps blow smoke through the overflow nipple while blocking the top entrance hole, to see where the smoke exits.


Good Fortune! [/quote]

What is the recommended type of smoke? :laugh:
Wayne

Doing pretty good so far. We've got smoke, crack, shaft, hole, blow, leak and nipple. :woohoo:

Good Fortune!

Fixed float bowl issue. Now it appears I am just pissing oil out of my crank case filter. I am running pods and do have a tube and filter attached to the breather hole in the crank case. I tied a rag to the filter and when I got the bike to 3000 rpm stationary it just started spewing. I didn't think this was an area of the bike that was under pressure and would release oil in such a manner. Any ideas as to why it is just spitting out the top of my crank case??

Bike was on side stand and stationary when i reved to 3k and got my discovered where the leak was coming from. I was just warming the bike up to take it for a spin.

Hopefully, you guys have some good news and a relatively cheap and not to difficult solution for me!

Rory Byrd wrote: Fixed float bowl issue. Now it appears I am just pissing oil out of my crank case filter. I am running pods and do have a tube and filter attached to the breather hole in the crank case. I tied a rag to the filter and when I got the bike to 3000 rpm stationary it just started spewing. I didn't think this was an area of the bike that was under pressure and would release oil in such a manner. Any ideas as to why it is just spitting out the top of my crank case??

Bike was on side stand and stationary when i reved to 3k and got my discovered where the leak was coming from. I was just warming the bike up to take it for a spin.

Hopefully, you guys have some good news and a relatively cheap and not to difficult solution for me!

I don't know a ton about these bikes but did you over fill the oil? I believe the sight glass has notches on it for max and min oil levels. Edit: read this kzrider.com/forum/2-engine/549111-1979-k...lling-from-crankcase

Nitsua,

The oil was not over filled. By the time I looked down and realize where the leak was coming from, my oil light had come on.

Would sniff-test and check crankcase oil for fuel contamination.

Am not a fan of the imo useless little filters on the crankcase breather outlet, that may actually impair breathing as it accumulates oil, dirt, water, etc.

Would toss the filter, get the issue corrected, and route a hose from the outlet to exit underneath the bike.



Good Fortune!

May be time to perform a leak-down test to determine whether excessive blow-by is over-pressurizing the crankcase.


A leakdown test injects air pressure through the spark plug hole to pressurize the combustion chamber.

Can perform a poor man's leak down test by introducing compressed air into a spark plug hole and listening to where it escapes from the combustion clamber. This may be done at TDC or any other cam positions where both valves are fully closed. Top dead center (TDC) is when the piston is at its highest position. An easy way to tell TDC is by alignment of the T mark with the case mark when viewed through the timing window.

May introduce a spurt of compressed air by using a rubber cone-tip blow gun (rubber air nozzle) held into the spark plug hole. And of course keep holding it in position to keep air from coming back out the spark plug hole while listening for escaping air at other places. The air compressor should not be running while listening because the noise will likely drown out any sound of escaping air.

Air heard escaping from exhaust port indicates exhaust valve not fully closing (perhaps too tight clearance or damaged valve or valve seat).

Air heard escaping from carb intake indicates intake valve not fully closing (perhaps too tight clearance or damaged valve or valve seat).

Air heard escaping from crankcase breather indicates loss of compression past rings into crankcase (perhaps worn piston rings or cylinders).

Air heard escaping from head gasket area indicates indicates loss of compression past head gasket (perhaps due to a blown head gasket).

A leaking valve may sometimes be resolved by adjusting the clearance to within specs.

A leaking head gasket may sometimes be resolved by torquing the head fasteners when the engine is stone cold (such as after sitting overnight).

Good Fortune!

If fuel entered the crankcase, it might have resulted from a non-functional overflow circuit in one or more of the carbs, often due to obstruction.

The obstruction in the overflow circuit may be anywhere from the entrance at top of the overflow tube to the exit from the overflow hose underneath the bike.

Good Fortune!

I am not 100%, but I may have figured out the oil leak. I removed the oil pan to inspect the oil pressure relief valve assemble at the recommendation of a mechanic friend who looked at my KZ manual. When I opened up the pan, I found that my oil pump strainer/screen was all gunked up and wasnt really pulling any oil. I cant be sure, but I am part guessing this may have played part in my problems. I am waiting on gaskets and O-rings so I can put the pan back on and test my theory. I did also clean the pressure relief valve along with all the crud that was in the oil pan. The whole thing was just dirty as I could imagine.

On another note, I am trying to find a set of 4-1 exhaust pipes to put on the bike. I don't want to pay too much for them. Trying to stay in the $150 range. Used pipes with holes and rust are okay. But if anybody knows where I can get some. I havent found any on Ebay recently. The junk yards around here dont get many bikes, much less KZs.

To all who are following this thread. I put the pan back on after cleaning all the gunk off of the strainer and cleaning the pressure relief valve. That seems to have done the trick! I rode about 80 miles over the weekend and I had no Oil issues!!! The bike ran pretty well. However, when I got to about 4500 RPM, I could tell I was running very lean. When I got back to the house, I parked, revved to 5k and held for a litttle, then killed the motor. Pulled the plugs and confirmed that I was running a little lean. I already have the new jets and will most likely re-jet this week. Its supposed to be rainy and cool where I am so its as good a week as any to do it.

I was also having issues with my starter not really catching when trying to start the bike while warm. IE - after I stopped for gas. It would kind of clank around a bit. Sounded pretty scary, but I was pretty far from my house and had to get it started and the kick wasn't working either. I basically had to finesse the bike into starting. I am asumming I will need to rebuild the starter. Anyone have experience with what I may be dealing with?