1976 A100 Smokes And Dies

[tbrown4x4]

I have a 1976 A100 with 2500 miles. It's complete and original, but has lots of surface rust. Previous owner couldn't get it running. It runs now, but smokes BAD. I suspected the right crank seal (I used oil leak dye and a black light to confirm there was gear oil on the spark plug and main bearing), and bought seals and gaskets for the repair. Pulled seal out of the inner valve plate and forgot which way it came out! I figured the lip with the spring should go toward the gear oil, but after starting it up, its smokes and dies even quicker. I must have put the seal in backwards, but before I tear it apart again I wanted to get some opinions on the problem. Todd

[Barry S.]

It may have been full of oil around the crank and will take some hard riding to get it all cleaned out. Make sure it is installed correctly and the cases are not machined so sharp that it shaved rubber off the seal when you installed it, ask me how I know this. I would think the lip with the spring seal may go towards the crank side.

[tbrown4x4]

I did get a chance to ride it pretty hard through the gears a few times before it fouled the plug and died. (Before I changed the crank seal.) When I replaced the seal I had the inner valve seat on the bench and the seal went in nice and straight, with no damage to the seal. I'm a little embarassed that I forgot how the seal came out, but I reasoned that it may not have been in correctly in the first place. I did not pressure test the crankcase because I wasn't sure how. I'm really being a baby about taking the seal out again, but I think I need to just do it. If it still smokes I might be looking at a tear down. I already have two engines apart and was hoping for the "quick fix". Todd

[rbond]

On all oil seals the side with the wrap around spring, faces in. Flat face, faces out. You also might try using some Hylomar gasket maker. It is like a grease in consistency and is fuel proof. This will lubricate slightly on the outside edge of the seal and help to seal that same edge at the same time.

[tbrown4x4]

Thanks for the advice. I'll try to swap the seal this weekend and let you know how it goes. Todd

[tbrown4x4]

Well, I finally got the right crank seal turned around. It helped alot and the bike runs well enough to run it around a bit. I tried to blow out all the old oil with a brisk zip around the neighborhood, and it seems to be running fairly well. Now I need to set float height and maybe adjust the oil pump. Does the starter plunger have to be down when running? The starter lever doesn't seem to have much effect, and it actually runs better in the "S" position. Todd

[H2RICK]

AA) What IS this fatal fascination with float heights ??
Don't mess with the float setting if the tang is more or less parallel to the float arms.
Better you should check the needle and seat for wear. This would be time more profitably spent, IMO.

BB) CHECK the pump setting FIRST before messing with the setting.

CC) Yes, the enrichener plunger needs to be down for the bike to run properly. You may want to pull the plunger and check to see if the rubber insert in the end of the plunger is still in good condition.
If the bike runs better with the plunger up, then you've got crud/varnish in the pilot jet/pilot jet circuit.....and probably the rest of the carb too.