bottom end noise

[DEmily]

Hey everyone,

Haven't really been on in a while. Been driving the BIGDOG every second I get. Got the breakin miles in and it is running great! I do have a concern though. I recently notice a noise coming from the bottom end. Kind of a clatter. It seems to be loadest on the stator side of the case. In fact it sounds like it is coming that exact spot. I wouldn't say it sounds like a bearing knock, but then again, I have had everything else happen to her. I took the stator cover off and noticed the crankshaft can be pulled out and pushed back a very small amount. Maybe 1 or 2 mm and of course makes a clunking noise as it is pushed in and out. I was wondering if there should be much side to side play. My first thought was the thrust bearings. Any ideas?

[John]

I hate to say it but I think your first thought is correct. Sorry. It wouldn't be the rotor is loose on the end of the crank? It is a tapered fit held on with a bolt.

[tab1324]

play in crank

Mine had a slight amount of play in it too, when I replaced the field coil (3 times). I don't have the low end noise though.

Tom B

[DEmily]

Help needed from the experts

Well, further inspection has left me puzzled. I started the BIGDOG up and grabbed a stethascope and attempted to find the clattering. It almost sounds like it is coming from the housing just behind the starter. If a put the stethascope on that housing it sounds like a kind of rubbing / tapping?

[srq68]

Could it be some slack in the hi-vo chain?

[DEmily]

I do not recall any type of tentioner for the main chain. If it is the primary chain, I would assume this would mean replacement and I have heard you can not get them.

[ratbyk]

Engine Noise-Rear

Check the oil level in your middle gear. Better yet, change the oil in your middle gear (good quality hypoid 90). The oil that drains out should be checked for metal cuttings.
Hope you find none and that your noise has gone away.
Ken/Sooke

[Geezer]

Originally posted by DEmily
I do not recall any type of tentioner for the main chain. If it is the primary chain, I would assume this would mean replacement and I have heard you can not get them.

If the primary drive chain is loose enough to make noise but isn't hitting anything. Drive on and ignore it but if it's hitting the case, the engine would have to be torn down to replace it. I'd have to look into this but I've heard that shops that sell car automatic transmission parts can custom make high velocity chains to order.

Geezer

[DEmily]

Sorry to bring this old thread back up. I think I found a good primary chain for the BIGDOG. I was woundering if it is possible to pull the moter and seperate the bottom with out removing the head. I really don't want to disturb the rings considering they are soooo nicely seated and the head is sealed nice and tight. Infact, I had a thread earlier that spoke of the compressin I was getting.
Everyone seemed surpised I was getting 170 and 180 even though it is all standard. Well, it's still showing 165 on 2 and 3 and 172-175 on 1 and 4, well after my wear in miles. It runs like a bat out of hell!! It is almost scary!
I really don't want to disturb the thing. Well at least as little as possible.

[Geezer]

Originally posted by DEmily
Sorry to bring this old thread back up. I think I found a good primary chain for the BIGDOG. I was woundering if it is possible to pull the moter and seperate the bottom with out removing the head. I really don't want to disturb the rings considering they are soooo nicely seated and the head is sealed nice and tight. Infact, I had a thread earlier that spoke of the compressin I was getting.
Everyone seemed surpised I was getting 170 and 180 even though it is all standard. Well, it's still showing 165 on 2 and 3 and 172-175 on 1 and 4, well after my wear in miles. It runs like a bat out of hell!! It is almost scary!
I really don't want to disturb the thing. Well at least as little as possible.

This can be done but I'd recomend a second person to help you lift the crank up so you don't damage the bearings.

This would also be a good time to do any repairs or mods to the transmission...

Geezer

[DEmily]

Greezer,

When you say mods to the trans. Are you speaking of the second gear thing?

[Geezer]

Yes and also polish the gear dogs for smoother shifting.

Geezer