Oil loss problems

My bike is burning through about 500ml of oil per 200 km. Any chance there is other problems other then bad rings? I know the compression is bad about 100lbs flat across all cylinders. The bike sat a lot in the last many years and my friend suggested the rings are just setting up after time and it might go away. Could there be other problems a foot?

I would really like to rebuild the engine but not tear the bike down just yet. Any one got any good sources on motors to rebuild?

Noticing any white smoke from exhaust?

Possible worn out valve oil seals or maybe valve guides.

Suggest leak down test to determine extent of compression escaping past pistons and rings into crankcase.

Possible head gasket leak.

Possible clogged crankcase breather.

Correct oil viscosity?

Any obvious leakage from engine seals?

Just thoughts.

Good Luck!

How does on-the-road performance feel?

Possible overheating for whatever reason, such as brakes dragging, worn chain, low tire pressure, bad bearings, incorrect ignition timing, improperly functioning advancer, too lean fuel mixture, too low fuel level, incorrect spark plug heat range, etc.

Good Luck!

On the road it runs really well. I have only ridden mine so I don't know what it should be like
I have not done a leak down test yet.
-I upgraded the coils and ignition to a Dyna system
-re shimmed the valves and resealed the head casket
-No leak from the engine.
- new K&N airbox filter
-Weirdgeorge wire upgrade
- new battery
- new oil
- rebuilt calipers and new pads
- wheel bearings seemed fine on the when it was apart


crankcase breather what is this?
How can you tell its overheating?
I know I have some exhaust leaks at the header and carb (parts on the way)

XL777 wrote:

On the road it runs really well. I have only ridden mine so I don't know what it should be like
I have not done a leak down test yet.
-I upgraded the coils and ignition to a Dyna system
-re shimmed the valves and resealed the head casket
-No leak from the engine.
- new K&N airbox filter
-Weirdgeorge wire upgrade
- new battery
- new oil
- rebuilt calipers and new pads
- wheel bearings seemed fine on the when it was apart


crankcase breather what is this?
How can you tell its overheating?
I know I have some exhaust leaks at the header and carb (parts on the way)

If no oil leaks from engine, crankcase breather is likely clear and okay. The breather is usually connected via a short S-shaper rubber hose connecting its outlet to bottom of airbox (where crankcase oil vapor is drawn back through the carbs into the engine where it is recombusted and expelled through the exhaust. But sometimes owners choose to bypass the airbox and just route a longer hose from the breather to expel underneath the bike.

Engine running too hot for whatever reason could cause oil burning, usually noticeable from exhaust.

Any white smoke noticed coming from exhaust, especially during acceleration or deceleration?

The leakdown test is more definitive.

Good Luck!

Any idea of the bike's true mileage?

38km+ is what the speedo says

XL777 wrote:

38km+ is what the speedo says

About 24,600 miles, and pretty low to have already worn compression down to 100 psi, but level figures are favorable.

Unable to accurately diagnose absent info about smoke from exhaust, and leakdown test results would also be most helpful.

Good Luck!

Probably has more miles than what the speedo is reflecting. If it's original speedo, 138,000 km is very possible. Time to rebuild the top end. That's about where I was on oil consumption on the KZ650 but had 160,000 miles on it. That's like a quart every 250-300 miles. I would ride with guys following me and ask them how much if any smoke was seen. Very little. I wonder what level of consumption some of these smokescreen cars driving around are at? Must be a quart every 50-75 miles.

Thats what I thought to. In terms of smoke I have not tested it since I re did the ignition wiring.

Mine was recently losing a bit of oil. If I went on an hour or two run, the level would moved from the top of the sight glass window to near the bottom. Way too much for such a short run. Noticed a small drip sometimes under the bike. Turned out it was the clutch pushrod seal had a chunk missing from the top. Fixed that and its perfect now, oil level doesn't move.

The thing is that I hardly noticed any oil leaking from this spot. It must have all come out while riding and only a tiny drop would show occasionally on the garage floor.

Thought I'd mention it as something to check. There are a few seals behind the left side cover to check. I cleaned up the whole area to help find the leak.

It would take a huge leak to effect oil level. Should have oil all over if this was the case. Another "trick" on a worn out engine is to maintain your oil level at the fill mark and not top it off above that. Staying lower on oil aided in minimizing oil consumption. I didn't make this up myself, read it many years ago and it does help on worn engines. Of course everyone here for the most part doesn't run worn engines Well I am the king of worn. Run til they won't run any more. I've never actually got there, they always run however worn for me good enough.