Oil leaks

Sounds familiar Dan, my Navigator crank shaft oil seal was leaking so badly into the primary chain case it was quickly over filling it with engine oil, making the clutch both slip and drag and then forcing its way past the clutch oil seal onto the chain to be sprayed across the back end of the bike! I stripped the whole primary side down, replaced the gearbox and clutch seals which weren't to bad to do. I then found someone had peened the crank case at three points to hold the crank seal (listed in NOC shop) in which made it a real pain to remove and an even bigger pain to replace - so much so that I damaged the first one and had to replace it. I used a copper scrapper to ease the peening back and then a thin film of lock tight to ensure the metal outer sealed in the crank case recess. I have done over 1000 miles since and the primary chain case oil level has stayed the same and apart from my stupid over filling of the oil tank the engine is staying 'sensibly' oil tight!

Nick

Oil on the backwheel I found eventually was the crankcase breather. Either the the thread holding the breather pipe was leaking , or the tube not sealed all the way back to the oil tank. I sealed up the crankcase breather completely because it is a nightmare to sort you have to take the the primary chaincase to access. I tapped a nipple directly into the breather oilway as it decends from the crankase. I noticed with Ullies bike he has a breather tapped directly into the crankcase. Never had oil on the backwheel again. It transformed my bike .

GRAHAM

how did you keep the dwarf out of the crankcase?

By getting Snow White to hold their hand?

Sorry!

Previously Dan Field wrote:

Interesting! Iâve seen a couple like that, how did you keep the dwarf out of the crankcase?

Dan

Hi Dan. Belt and braces:-

1.With the primary chaincase removed, remove the crankcase breather tube and the grub screw sealing the oilway. Clean the oilway of all oil so that swarf is less likely to stick.

2.Fit a dowl a slightly loose fit into the oilway. (it shows the direction and length of the oilway into the crankcase).

3.Drill a pilot hole to meet the oilway and dowel, when it tickles the dowl you know to stop. Clear the swarf from the hole that you drilled down to the dowl.

4. Measure the depth of the oilway that you drilled to. Drill and tap the new breather connection to that depth.

5. Remove the dowel. Pass pipe cleaners through your tapped hole and down the oilway where the dowel was removed.

6.connect your new breather connection. blow compressed air through your new connection exhausting through the original crankcase breather connections.

7. Remove your new breather and illuminate the passageways for debris.

8. Seal the original crankcase breather and refit the grub screw.

9.Assemble the engine , but feed the new crankcaase breather into a clean jar.

10. When you run the engine eventually, sumping from the crankcase will exhaust into the jam jar.

11. Inspect the oil for contamination. If clear you can be quietly confident to connect the crankcase breather to the oil tank.

12. If there is debris still there it will be captured by the fine gauze at the bottom of the oil tank, or if in the crankcase in the fine sump filter. If swarf is too smal to be stopped by filters it can be captured by remote oil filter you have fitted.

13 Change the oil after a brief running in.

If nothing else you can be sure the oil underneath your bike is not from the crankcase breather or from wet sumping.

GRAHAM