Topic: HELP!!! Engine case break at oil pump

[cprice9]

Hello all,

I am working on a 1974 CB550 and have hit an issue that Im curious what to do about, if anything.

After having drilled out the left side sprocket cover (b/c 1970's Honda engineers though it was logical to put an engine together with phillips bolts?!?!?) I found a ton of gunk, and some metal fragments!!!

After further exploration the metal fragments have come from a broken oil pump housing wall on the case and the cover.  It appears that a broken chain is the most likely culprit.








It doesn't appear that a repair is possible, the only solution I can imagine would be replacing the entire engine case which Im not trying to do.

Im definitely going to replace the cover, but that will still leave about a 1" square chunk missing from the engine case side of the wall.

My question deals with importance, does the oil pump have to be completely isolated from chain splatter or is it something that can be cleaned up and left alone?  How make or break is this?  Has anyone dealt with this issue before?

Thanks.

[Damage Inc]

I'm not sure if I see all the damage, I can't make out the damage to the oil pump. If its just to the housings there is a good chance you can strip it down bare and get a good tig welder to weld it up, then you can clean it up with a die grinder or if its a sealed surface it may need refacing.

[iron_worker]

By the looks of it that is a "dry" area where the oil pump is located. As in you're not trying to seal the engine oil in so that plays in your favor. I would say it would be the end of the world if your chain was throwing grease on the oil pump but I would be tempted to track down a welder to patch it. It shouldn't be a hard job if the case is clean.

IW

[01Thomas]

Hi
If all you want to do is isolate the oil pump from the road/chain detritus a fibreglass repair should do the job.

regards
Thomas

[cprice9]

thanks for the advice, seems we are all leaning in the same direction.

[Bankerdanny]

It is hard to see through the chain/road grime, but it does not appear that this is a part that keeps oil from the inside from getting to the outside or that it is a structural piece like where the tabs for the engine to frame bolts.

If that is the case then I don't see why a careful application of JB Weld followed by some sanding wouldn't be sufficient.

[cprice9]

From what I gather it seems that it is just a wall built into the case, not pressure bearing that isolates the oil pump from front sprocket gunk.  My only guess is a popped chain hit it, i will clean it all up soon and post some better pics.