Wanting to clean the crank case

[teck_mountain]

And the repairs go on,.........

I've finally cleaned the remaining old gasket off the crank case. What a job,... I notice that there seems to be a lot of stuff, grime of some sort, on the bottom of the crank case. I would like to clean this out, without removing the engine. Some one mentioned using diesel fuel. Was this right? If not any other suggestions?

Teck

[Pat Kelly]

Remove the oil pan to clean it. Leave the cases in the frame.

[rover]

Diesel fuel will clean somewhat, but that is VERY risky. Clean the oil pan, which can be removed from the bottom. Auto transmission fluid type F has a lot of detergent in it. Take out about a pint of oil and add a pint of type F auto tranny fluid, and put on about 50 EASY miles, and then change oil AND filter. This will clean all the places that oil goes to. Do not push the bike too hard with the tranny fluid in it, as the lubricating qualities are reduced. The idea is to circulate the oil and fluid and let it clean everything, It even can make a chattering clutch smooth again. But remember to TAKE IT EASY. Rover

[MartyA]

I had a boss with a 20 year old Harley. Every fall before storage he drained his oil and he put 4 quarts of diesel fuel in, run the bike till warm, then drain the crud that comes out. He said you wouldn't believe what comes out.

I told him I thought that that was dangerous, running an engine with basically no lube. He said I was probably right, but after 85,000 he wasn't worried. He rode it to Sturgis last summer, 1,500 miles then back again. Never had the engine out or apart.

[John]

Diesel fuel actually has quite a bit of oil in it. The oil is required to lubricate the injection pumps on most diesel engines. Without the oil, the pumps would gall, and seize. Where I work, we had a difficult time convincing management that by running jet fuel in our diesel engines, we were doing more damage than we were saving in fuel costs. Caterpillar won't warranty an engine that has been run on jet fuel, so it can be very costly. In fact we've had to have two fuel pumps rebuilt this past week, and the warranty had been voided by the use of jet fuel. If an engine is run with diesel in it instead of oil, it should be ok, just don't run it hard. Idling/ light throttle won't hurt anything.

[steelcat]

Yeah, diesel will clean the engine out good. In fact TOO good. I'd only use half a quart of diesel, otherwise you run the risk of removing the oil film from between rod bearings. AFT is a bit safer, but only a quart. Refill an start up imedatly after both techniques. Just let the engine idle to warm with either the diesel or the ATF. I'd stay away from commercial engine cleaners, I had very bad luck with some & had to replace the rods and main bearings afterwards. Now days I just stick to using AFT if needed.
The best practice is to change your oil often and use a high quality oil.