hi..shortly i will be changing the engine oil and filter on my k100rs before i do the bike has stood for 8 years,, do i need to flush the engine if i do which is the best way to do this and which stuff is best to use i will be changing the gearbox oil as well...............when i collected bike i rode it 10 mile home she smoked quite a  bit like a white very light blue smoke for 6 mile then it cleared and she used no water...regards  jim      

I don't recommend flushing, but I would replace the oil and filter, ride for 500k and then replace oil and filter again.

Hi Jim,
I am a strong enthusiast for cleaning up old engines using high quality diesel engine oil like Shell Rimula or similar. Do NOT use flushing agents you risk destroying your engine because if they release clumps of crud those can block oil galleries and cause oil starvation. I have a friend who was an engine reconditioner and he told me he has lost count of the engines he got to rebuild from just that cause.
The diesel oil has a high soot carrying and detergent nature and gently lifts the deposits off so the filter can pull them out. Use a top quality filter as Bert says for the first 500 miles of preferably hot running (take a long trip. And change the oil and filter again putting the correct viscosity diesel engine oil in again. Any diesel oil recommended for mixed fleets is the way to go.
Regards,
K-BIKE

I bought a K75s cheap I used Slick50 from Halfords A good way to flush out your motor.

PS. Starter motor Brushes can give all manner of unexplained electrical
problem if worn low.

I personally would take the whole sump pan off and give it a really good clean. You may get a bit of a shock to see what is in there!

Hi Guys,
I would strongly suggest you DON'T use any PTFE based engine treatment in your engine. There is a wealth of info on the net about them. Your mileage may vary as they say.
Regards,
K-BIKE

blakey wrote:I personally would take the whole sump pan off and give it a really good clean. You may get a bit of a shock to see what is in there!

Have a look at the befor and after pics.

http://cid-a5226878da38d80a.skydrive.live.com/browse.aspx/K100%20shared/Technical%20shots%20documentations/Oil%20Pan%20July%202009




Roy

Old thread, but...
I've found this on a Goldwing site. It is a formula to do an engine flush to free up rings and remove general crap.

I have no idea if it works, but it may be useful to some people:

.......

1. Fill crankcase with a 50/50 mix of cheap 30W and Dextron auto
   transmission fluid.
   
2. 
   Start engine and run for 20 minutes at 3500 - 4000 rpms on the
   center stand...DO NOT RIDE with this mixture in crankcase...any
   loading might damage your engine. This will clean your engine
   internals and free-up rings. Don't be alarmed...your engine
   may SMOKE quite a bit with this mixture!
   
3. 
   While the engine is warm, drain this oil mixture.
   
4. 
   Replace oil filter (again).
   
5. 
   Refill crankcase with high quality, motorcycle-spec 10W-40 oil...
   

There is a lot more here : http://www.randakks.com/TechTip24.htm

A buddy (professional mechanic and K100 rider) had a problem with the sprag clutch on the K100. He flushed the engine with this mix and solved the starter problem.

CF, it is good to get a confirmation for people who are just starting to restore their rides. Ajays has confirmed that synthetic oil does the same job, but this reasonably cheap option is also welcome.



I would use a cheap 20w-50 mixed with Dexron, simply because of price and ease of getting cheap recycled oils.

Hi, after so many years, what are your current recommendations on engine flushing? Over the past dozen or so years, the technology has changed a bit.
My "brick" K100RS has now been sitting for 5 years without being ridden (but started every year). This year I would like to replace its valve seals and adjust the valves. But first, give the engine a little flush. Is the diesel oil patent still recommended by you?

I would say that if you aren't having sprag clutch problems all you need is an oil change and a new filter.  Virtually all the oils available for the last 30 years have detergent packages that do a great job of keeping the crap in suspension until the filter can grab it.  As long as the oil was changed regularly less than every 5 years, 50,000 miles you won't have any sludge buildup to deal with.  

If you really need to know if dirt is building up, pull the valve cover and do a valve adjustment.  That will give you a pretty good idea of how much crap is in the engine.

Basically, you're right, if nothing is happening, there's no point in trying to fix it

Point-Seven-five wrote:  As long as the oil was changed regularly less than every 5 years, 50,000 miles you won't have any sludge buildup to deal with. 

This seems to be one of those rare cases where less could actually be more.

I have sprag clutch problems (starter cant crank the engine) and was told a flush was a good idea.
I Can bump start it no problem so i think maybe an engine flush would be a good cheap and easy Way to maybe solcentre problem.

Advisable? 

BMW K100 from 1984.

DanielBN_K100 wrote:I have sprag clutch problems (starter cant crank the engine) and was told a flush was a good idea.
I Can bump start it no problem so i think maybe an engine flush would be a good cheap and easy Way to maybe solcentre problem.

Advisable?

You certainly have other choices, Daniel. 

You can always look for parking spaces that have a downhill pitch so you can bump start the Brick without effort. 
You can build your coordination and upper body strength by running alongside the Brick while pushing it, hopping on and then bump starting it. 
You can remove the transmission and rear drive, disassemble the engine until you reach the sprag clutch then clean the clutch housing, clean all the sprags, inspect them for function, reassemble the clutch, install the clutch, then reassemble the engine until you can start it to determine the success of your efforts.
You can sell the Brick as-is.

I've seen many sprag clutches on Ks saved by using diesel engine oil. It's more detergent than the oil for petrol engines, and cleans the sprags.
A good battery and a good starter help also...

Hi Daniel 

If the problem only started after an oil change to a new engine oil brand with some super duper friction modifier additives, that might be a problem. Bricks are unusual in that the engine oil is used for a clutch relying on friction between two smooth metal surfaces.

Im using a semi-synthetic oil 10w-40 that was suggested to me. Switch to another?

If you changed oil brands and the problem started after using this new brand, then yes the oil could be the problem. Then you want to read the label and see if friction additives are mentioned and what they are. Usually they are a benefit but might not be suitable for bricks. I think this has been a problem on the forum in the past.

I think one member, also from Denmark, was also recommended to change the oil brand, but it was an oil with some super friction additives I thought, and the clutch kept slipping.

Can you post photos of the labels on the oil jug?