If the seal spacer is worn it will have grooves worn in it, not a reduction in diameter.
Have you got the right sort of seal there? It should have two lips in opposition. Looks like a single lip seal in your photo.
It's possible that as suzuki250 says, one or both main (crankshaft) bearings may be shagged which can cause the seal spacer to move up and down enough for the seal to leak past the lips even with a nice new soft seal. You should be able to feel that degree of play in the mains by trying the move the end of the crankshaft up and down by hand.
Another thing is that it is normal to find that much oil in the bottom of a two stroke, but it should look and smell like your brand of two stroke oil.
The definitive symptoms for oil getting sucked into the crankcase from the primary drive are weird smelling exhaust smoke, too much exhaust smoke, weird colour (white) exhaust smoke and having the oil disappear from the primary drive casing. You have only mentioned one of these symptoms.
Hi, yes it is a single lip seal. I replaced what was there before but if a double lip seal is the way to go Im happy to do that.
I did check the main bearings and I could find no noticeable play on either side of the crank.
This oil is definately coming from the primary side, it smells the same and the oil in the primary casing when I took it off was nearly zero and I have no other leaks from there.
Yes, forgive me for not mentioning the exhaust smoke. It smokes a lot and the smoke is white. I haven't noticed the smell of it though.
Tricky to know what if I should go for a crank rebuild here.
I found that the amount of oil that had come from the primary side as there was next to none of the oil left in the primary casing.
I have already changed the crank seals but this is still not working.
Do I have the seal in the correct way? It was the same way as the one I took out.
Is the gasket around the seal holder likely to be the culprit?
I couldn't get my mic on the crank where the seal sits due to clearance issues but I did get my digital caliper on there and I measured it at 24.85mm. Seems a little small.
I have my left and right flywheels, not swimming, but there is a lot of oil on them as I turn the crank. If I wipe the oil off its on there again after one revolution. I have recently changed the crank seals, so this seems odd to me.
Is this a sign that the crank seal is failing already or is it a possibility that somehow oil is getting through from the gearbox or somewhere else on the primary side?
Hi, I was looking to replace the piston and re-bore my '71. Piston kits look pretty pricey, am I missing something or is that just the way it is. The cheapest I've seen one is £175.
This is a good shout. I have an Electrex ignition on my '68 TR6R and it has always been brilliant. I hadn't realised they did a kit for the Montesa so that will be on my wish list for the summer.
Hi, thanks for the reply. Am I reading that as the red wire goes to the frame that this is a positive earth setup and the black wire goes to the single terminal on the coil?
Wires from the stator plate don't match up with the diagram but on my engine the white is converted to red - so positive and the black - well negative!
Engine oil on left and right flywheels - 247
in Montesa
Posted
Hi, yes it is a single lip seal. I replaced what was there before but if a double lip seal is the way to go Im happy to do that.
I did check the main bearings and I could find no noticeable play on either side of the crank.
This oil is definately coming from the primary side, it smells the same and the oil in the primary casing when I took it off was nearly zero and I have no other leaks from there.
Yes, forgive me for not mentioning the exhaust smoke. It smokes a lot and the smoke is white. I haven't noticed the smell of it though.
Tricky to know what if I should go for a crank rebuild here.