Tons of blow by, hardly any smoke

Hi everyone, excited to be here. Just purchased my first Kawasaki a few months ago, and after stripping it apart and rebuilding it, I’ve got an issue. Took her out for her maiden voyage. Checked the oil amount when i filled it plus glass window was 3/4 covered and within the range. Running stock air box, but with a little pod filter on the crankcase breather (because originally I put pods on the carb. After 25 miles, I realized the engine was pumping oil out breather vent. I was covered tires were covered, bike was a mess. Glass was much lower. Turned around and headed hone and by the time I made it the glass was down to low- so basically went from just below high to low in 40 miles. The entire top end was covered in oil front and back. I have a tiny amount of smoke just on warm up of the left cylinder, but none while riding. She dogs a bit when I first get in the gas, but doesn’t seem to have the loss of power you’d expect if the rings completely failed on one side. With no smoke, and decent power, is it still probably the rings or is there something I should check first? Thanks for your help! I’ve already put a couple of months into this thing and the weathers getting warm!

Welcome along for the ride. We probably need more concise info. Did your rebuild include new rings, honing, rebore etc? For oil to come the breather you must have excessive crankcase pressure as you mentioned. What oil are you using?

Didn’t touch anything on the motor as everything was running great and mostly wanted to make changes to the look of the bike. I will say, the day I rode it home and took the engine off the frame for powder coating, the oil light came on. Using the recommended 10w-40

Thanks again for your help!

Fully synthetic, semi synthetic or mineral?

Mineral I believe but my roommate threw away the bottle so I can’t be sure. It’s been a few weeks.

Compression test readings?

Haven’t run a compression test yet- need to find one to use.

Just to make sure - did you set your oil level when the engine is off, and on level ground on its centre stand? Too much oil will cause the symptoms you're describing.

Irish Yobbo wrote: Just to make sure - did you set your oil level when the engine is off, and on level ground on its centre stand? Too much oil will cause the symptoms you're describing.

That is a good shout. If you filled the oil with the bike on the side stand, as the sight glass is on the other side to the side stand it will read low, if you filled to the marks you would have loads too much oil in it.