Cleaning the sump after Rebuild

daves79x · Post by **daves79x** » Wed May 20, 2009 9:52 pm

I thought I'd post this since I've seen it on every engine rebuild I've done.

Despite your best efforts to clean all internal components upon reassembly, there will remain debris and fibrous material (even using paper towels instead of shop towels). That's a no-brainer, but the amount of such debris will amaze you. My suggestion is to first install a new sump screen during the rebuild - the old one will probably break when you take it off anyway. Then run the engine maybe a very few miles. Drop the oil, filter and sump cover to clean out the sump and screen. It will have a remarkable amount of debris on it.

Then repeat the process except drive maybe 50 miles. There will be more debris, but markedly less. Then again at 300 miles. You should be getting down to normal bits of this and that, but essentially by then you should have it pretty well cleaned out.

You will swear that you couldn't have left that much debris behind, but it WILL be there. I know all that oil and filters is an extra expense, but I believe it will be worth it in the long run.

Dave

Terry · Post by **Terry** » Wed May 20, 2009 10:59 pm

Good info! I removed the pan on my 79 some years back and found the screen had what I guessed was, dozens of gasket goo entrails hanging from it. I took the screen off and was able to clean it but the rim was so hard and non flexible, that I couldn't get it back on w/o ruining it. A Honda dealer ordered me a new one that went on with no trouble. Glad I looked at it.

cbx6ss · Post by **cbx6ss** » Thu May 21, 2009 10:20 pm

Good advice. After finding the same the first time I dropped my pan, I now check the sump on every oil change. There always seems to be something there too.
/r
Brad

alimey4u2 · Post by **alimey4u2** » Fri May 22, 2009 4:56 am

I think the use "running in oil" to be flushed after 500 miles is a good regimen. together with this advice the engine should be good for 100,000 miles...

That brings me to the question: What mileage should one expect from a CBX engine that has been unmolested ? I know we have some high milers here...

cbxtacy · Post by **cbxtacy** » Fri May 22, 2009 11:52 am

I've had quite a few over 100,000 miles. My valve adjustment interval isn't ideal but I religously change the oil. Sometimes under 2000 miles, if it was ridden hard for a few miles I can feel it in the clutch/shifting and fresh synthetic makes it feel good. My engines do see 10,000 rpm and if they won't go there, I consider there's something wrong with them.

sixofsix · Post by **sixofsix** » Sat May 23, 2009 4:47 pm

...well, I've got 180,000 kms on my 79 and the engine has never been apart. The usual valve clearance checks, carb sync's, carb rebuilds a couple of times over the last 30 years, a couple of fresh sets of clutch plates and clutch outer once..lots of oil changes and certainly sump screen checks/ replacements..

...and like George, run it to redline, run it fast, hard and don't overheat it.

Change oil lots, do the suggested maintenance, and enjoy.

...did I mention change the oil?

...and you can run a CBX at 140 kms/hr all day long, just lube the rear chain and smile.

Tony

cbxtacy · Post by **cbxtacy** » Sat May 23, 2009 6:03 pm

and don't forget to change the oil.

My first CBX I bought in Germany in '83. It was an 82. I'd run it down the autobahn at 190km/hr. At that speed I'd hit reserve sometimes at 100km.

and don't forget to change the oil.

They get lousy mileage at that speed.

and don't forget to change the oil.

Did I forget anything?

alimey4u2 · Post by **alimey4u2** » Sat May 23, 2009 6:42 pm

cbxtacy wrote:Did I forget anything?

Did you mention the oil George, that's important...