Upcoming project

[Larry D]

I'll be sure to take some pics.

My '81 GS750L had some topend oiling problems and roasted the #1 intake camshaft end and journal. I'm going to get a "new" engine to replace it with on Sunday. I plan on simply swapping engines for now, to get riding again, providing that there's no issues with the replacement engine. The roasted engine is going to be cracked open, inspected and possibly replaced because I know how many miles are on it and there are unknown miles on the replacement. I may also just replace the camshaft and head from the donor, if I can clean the original engine oil passageways and there aren't any other problems with it. SO...

When I get the old engine out and opened up, how do I go about cleaning out the teeny-tiny oil passages in the engine ? Seafoam and some compressed air ? Perhaps some other cleaning product and blow it out ? Is it just washing out the engine or should I try running something small, flexible and soft enough not to scratch the innerds ?
Thanks.

[Dave8338]

Hey Larry...If you're going to all that trouble, take it all the way down and bring it in to get boiled out. It'll remove ALL crap and crud for the block and head.

[Larry D]

Hey Larry...If you're going to all that trouble, take it all the way down and bring it in to get boiled out. It remove ALL crap and crud for the block and head.

I don't know what that means.......take it in to get boiled out....

I understand the concept but, I take it somewhere and they boil the engine ??

[Dave8338]

Yep! I've had several aluminum heads boiled (in what I'm not exactly sure) and when I'm get them back, they look like new. Find a GOOD shop that works on engines/heads and they should be able to hook you up.

[Larry D]

Yep! I've had several aluminum heads boiled (in what I not exactly sure) and when I get them back, they look like new. Find a GOOD shop that works on engines/heads and they should be able to hook you up.

Okay, I'll look into that. In general how much does something like that cost ?
Thanks.

[Dave8338]

$75-$100 depending on the going rate where you are located.

Keep in mind that you'll be waking through the door with a box or two of pieces parts, not the entire engine in one lump.

[Nessism]

You can check most of the passages yourself using a garden hose. After degreasing the head with gunk or similar, wash the head down and force water though the various oil passages to make sure they are open. This is what I did on my 1000 cylinder head and it worked well.

Good luck,

[Larry D]

I've been doing some internet searches.

Seems there is a huge difference between "hot tanking" ferrous metals and aluminum. I think I found a couple places in Indy that offer the service. Going to give them a call and see what they say.

Continued......I called this place. Aerohead Industries: Racing Cylinder Heads & Engine Parts
(317) 862-0223 8621 Southeastern Ave
Indianapolis, IN

They said they were an aluminum engine specialist and hot tank aluminum parts almost daily. The guy was informative, he said they hadn't done a motorcycle engine before and would probably be around $50. Not bad for an engine completely clean inside and out.

I think I'll go with Ed's method first though. No need to spend money if you don't have to.

[Nessism]

Hey Larry,

The oil comes up the outside stud holes. I put a nozzle on my hose and then stuck the nozzel into one of the stud passages from the bottom and plugged the top with my finger to force the water to enter the oil hole passages. The water then will move sideways though the head and will come out the holes on the bottom of each camshaft bearing.

Regarding oiling the engine in general, I've read here that some people shim the oil relief spring to increase oil pressure. It seems to me that the 750 engine is not putting out enough oil for some reason so you might want to investigate this mod.

[Larry D]

I've read about shimming the oil pump. However, I think my oil pump is working well. Everything else in the topend looked well oiled.

I think what happened is that for the last two oil changes I used Rotella 10W-40 diesel oil and it cleaned so well that a chunk of something clotted up the passageway on that side. That's my story and I'm sticking to it.

Actually it wasn't two oil changes, just one. The problem occured about 50 miles into the second oil change with the Rotella. Nothing against the oil at all, I like the Rotella and the engine seemed to like it alot. Ran smoother, shifted easier, etc....I'm going to continue to use it regularly.