Author Topic: Sludge (Read 1775 times)

Lupo_00 · « **on:** August 20, 2018, 06:01:50 AM »

Hey guys,

I’m looking to clean up and paint my engine rattle can style. I bought my 750K1 (33k miles on the odometer) with K3 engine from someone who had it sitting for probably a decade after draining the fluids at some point. I got it to start up but haven’t gotten it on the road yet. Found sludge in the gearshift cover (the bike only has a side stand and has been leaning on it since February). I have two questions:

1. Is this amount of sludge normal and will it work it’s way out with some riding and a few oil changes? Or do I need to take the engine apart to clean everything? The engine is already off the frame... was hoping to avoid a rebuild as long as possible.

2. Am I putting the cart before the horse here by painting the engine and then riding it? I have no idea if there are any leaks etc.

Thanks in advance.

PeWe · « **Reply #1 on:** August 20, 2018, 06:33:52 AM »

My engine has never had oil sludge inside.
I should try to clean it.
Open oil pan (probably dirty here), remove oil pump, open valve cover and all the other covers and flush it with a few liters of naphta in a plastic box where engine can sit and reuse the naphta. Remove plug over the ignition to flush the oil transport.

When cleaned and engine to be started again, use a cheap Motorcycle oil that can be just started for a few minutes high idling, change oil. Ride bike and change oil once again after a few miles.

Engine might need to be restored. this will drain your wallet since the gasket, seal kit and o-ring will cost. Plus tensioners that most likely have hard rubber.
Head might need to get seats cut + valves lapped. All chains inside replaced too.

Kevin D · « **Reply #2 on:** August 20, 2018, 07:00:35 AM »

Show some photos.

Lupo_00 · « **Reply #3 on:** August 20, 2018, 08:05:57 AM »

I forgot the photos!

754 · « **Reply #4 on:** August 20, 2018, 10:17:13 AM »

I tried replying earlier, must have clicked wrong.
It looks bad, I would drain your oil, see what is laying in filter housing , drop the pan and clean. Then see what happens.

Lupo_00 · « **Reply #5 on:** August 21, 2018, 06:25:11 AM »

Got some sludge in the pan too (and what looks like a dead worm), but seems clean-ish up in the engine. I got a suggestion to do an old farmer's trick. Drain the oil, replace with kerosene, roll it over, don't let it start for about 30 seconds, let it cool down, roll it over again. Drain, put in fresh oil, run til warm, drain, add new oil.

Does anyone see anything awful about this that's bike specific?

PeWe · « **Reply #6 on:** August 21, 2018, 08:27:44 AM »

There is a risk that sludge will enter the oil channels up to head and block the oil flow to cam and rockers. This will destroy cam, rockers....

I should open the entire engine, clean it and restore it. Then you will get an engine you can trust and avoid a stop somewhere that will cost.

TwoTired · « **Reply #7 on:** August 21, 2018, 09:14:39 AM »

Have you found a liquid that dissolves the sludge?
Test if kerosene or diesel fuel will thin the sludge.
Then use enough of that liquid to keep the oil pumps primed and spin the engine until you can see flow at each end of the camshaft rockers, drain and use w10-40. Then crank engine again untill it also flows at the camshaft rockers.
If it does, start it up, still watching for oil at camshaft rockers. When it is fully warmed up, change the oil again.

Or.... Take it all apart for cleaning.

Cheers,

Edit: spelling correction

Lupo_00 · « **Reply #8 on:** August 21, 2018, 09:18:01 AM »

Thanks guys and good points all around. I unfortunately cleaned the parts I found with sludge already. I'll look for more sludge and test out the solvents, then see if I need to tear apart the engine.

PeWe · « **Reply #9 on:** August 21, 2018, 09:23:28 AM »

Sludge can be one indication for really long oil change intervals.

SOHC4 Cafe Racer Fan · « **Reply #10 on:** August 21, 2018, 02:27:57 PM »

That's the type of sludge I call "gravy." No bueno. At a minimum, drain all of the oil, drop the pan, take a apart and rebuild the oil pump. I like Two-Tired's approach.

pjlogue · « **Reply #11 on:** August 21, 2018, 02:51:46 PM »

You would be wise to pull the engine, take all the covers off and the head and check the oil nozzles in the top end. That "worm" like thing in the oil pan looks like silicone sealant and quite a liberal application of it. A little extra work not may save you a whole lot of work and money later.

-P.

calj737 · « **Reply #12 on:** August 22, 2018, 04:46:55 AM »

Depending upon where you live, Kerosene may not be readily available. Diesel or Kerosene will very likely reduce that sludge and your method of circulating, draining, filling and running, then draining again sounds just about right. Diesel stinks to high heaven and is difficult to dispose of. Kerosene is obviously VERY flammable, so do use care. Easier to dispose of afterwards with a safe, outdoor fire one evening. Will help drive away the Mozzies too!

When you first fill the oil with the sacrificial batch, don't use a synthetic or blended oil. They can sometimes react differently to a solvent depending upon the oils. Just use a cheap conventional oil, maybe even in a lighter weight too since its only going to be cycled, heated and drained.

BobbyR · « **Reply #13 on:** August 22, 2018, 03:13:32 PM »

The kerosene is an old school procedure and works well. Some of the products on the shelf are not much more. Sludge was a big problem up into the 1970's when detergent oils became popular. Two Tired gave you the procedure used. If you want to yank the motor it is a lot of work.

Kerosene is a a good solvent since it is oily and will not attack seals etc.

Lupo_00 · « **Reply #14 on:** August 25, 2018, 10:31:03 AM »

Thanks again everyone. Obviously with the support of kerosene or diesel fuel here, my engine is not going to explode from this process right? 😬

PeWe · « **Reply #15 on:** August 25, 2018, 10:52:45 AM »

No problem as long you do not smoke while cleaning

I think you can smoke too..

scunny · « **Reply #16 on:** August 25, 2018, 03:46:25 PM »

I've used diesel to clean out a dirt bike engine that was full of sludge, took a few goes but it's effective.

BobbyR · « **Reply #17 on:** August 26, 2018, 09:29:12 AM »

Quote from: Lupo_00 on August 25, 2018, 10:31:03 AM

Thanks again everyone. Obviously with the support of kerosene or diesel fuel here, my engine is not going to explode from this process right? 😬

If you are away from open flames it is very fine unlike Gasoline. Kero does not stink as much as Diesel fuel. You can get water white Kero at gas stations for Kerosene heaters or you can get it at big box hardware stores.

Don R · « **Reply #18 on:** August 26, 2018, 01:30:19 PM »

That looks to me like water in the oil. At any rate proceed, I hope it cleans up ok.

Kevin D · « **Reply #19 on:** August 26, 2018, 08:07:52 PM »

How long did you run the motor? The oil pump will try to move the sludge.

What did the filter look like? The filter should catch that stuff until it is plugged.

Did you look in the oil galley above the points cover? Hopefully clean here meaning none of the sludge got past the filter to critical parts like crank and cam bearings.

Make sure you rinse the bottom of the oil tank.

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Author Topic: Sludge (Read 1775 times)