Hi Guys,

I had a great run out this weekend doing a couple of hundred miles in great Scottish scenery but the bike is using oil. I haven't quantified how much but thought I should inspect a plug or two, results below. Doesn't look good to me; there's wet oil and burnt oil although the electrodes look OK.

Can anyone help with diagnosis and options please?

Thanks
Dave

Image hosting seems to have problems will try again later

They look fairly normal, mate. The centre electrode is a bit rounded off, perhaps from age, the ceramic looks white enough to be about lean but still running, and the threads have captured a bit of that usual black oil residue. If you have the means, check the compression with a decent quality gauge. It should land somewhere north of 120 psi to about 150 psi on a good day. You don't want a ten psi difference between cylinders. If it turns out to be low, like 100 psi or less, add a teaspoonful of oil into each cylinder and see if it rises a fair bit. That might indicate the rings as the culprit. How does she run otherwise?

My bike uses virtually no oil between changes at 4 to 5000 kilometre intervals, and the plugs look about like yours do.

Cheers Guest! So you can see the photos? I can't see them - odd.

Anyway, that sounds like it might be good news - thanks .

I don't have access to compression testing equipment but will see if I can borrow some and then follow your advice. It could be that I'm losing more oil from the drain hole in the bellhousing than is obvious?

She runs really well, starts well, pulls smoothly - so no problems. No black smoke either that I've seen.

If the mixture is a little lean I should maybe adjust - I guess Haynes or Clymer would say how - would this be done before or after balancing throttle bodies?

Thanks again
Dave

It's a miracle I can see the photos now too!

Have just read the Clymer - if the mixture is too lean maybe it was drawing air in from somewhere. I've recently changed the TB rubbers, various hoses etc hopefully it should be good now but might have been leaking in the past and making the mixture too lean. I'll stick new plugs in soon and see how they look.

Best
Dave

If your bike was using noticeable oil and it was coming through the bellhousing weep hole the clutch would by now be slipping and spinning like a politician's shiny promises.

I wouldn't play with the mixture yet, or at all, until you know what's what with things, and as it looks from the pictures, as these bikes can be run pretty lean and get away with it. As I said, my sparkies look about like that.

Black smoke is commonly indicative of a too-rich fuel/air mixture, blue smoke is burning oil, and if it blows when decellerating that's usually worn valve guides as it sucks back through into the combustion chamber. White smoke isn't a very good thing at all.

You won't be balancing the TBs at anything but idle since the only control, without Very Special Equipment, is the air screws at the TBs base. I wouldn't concern myself with that at this stage. See if you can get a compression tester with the correct thread size, whiz out all of the sparkies and give all the cylinders a good crank to see what it climbs to. Keep in mind that a tight intake or exhaust valve will return a low compression reading for that cylinder since it isn't closing all of the way, which obviously lessens its ability to pump up to the proper level sufficiently. A thorough check of the valve clearances when the engine is stone cold is a good start.

In short, if the engine is running well, returns good mileage, climbs hills well and overtakes as expected, she's probably right. Taking care of some of the basics, answering some simple questions for peace of mind, is the best place to start.

Cheers.

Thanks Guest . Gotcha.
Best
Dave

Dave, how far did you fill her up?? Experience shows that putting in more oil than mid-level in the sight glass gets it burned up rather quickly, after that it stays there (mid level;with a good bike). Don't go by the amount in the book, fill her until the red dot/mid level in the sight glass. Further it can take different amount of time until all oil is back in the sump, so leave it for some time before you check. The 1100's are known to use some oil, but the 1000's and 750's rarely do, even the high mileage bikes.

MT350Explorer wrote:It's a miracle I can see the photos now too! Dave

I edited the post

Thanks Bert - not sure what happened my computer is on a go slow....

dave ,,,just as a comparison

heres one i exchanged out recently ..



i concider mine runs a little rich ...and most of the work it has done was with leaking throttle body rubbers and is just after the rubbers fix by about 200k trip home ...i recon they have done in excess of 25,000ks of service

i guess in time if i can borrow an gas analyzer and get the mix better , that would be good along with an engine overhaul ,,,replaced valve stem seals ...valve grind and rings ...etc ..

Guest in the House wrote:If your bike was using noticeable oil and it was coming through the bellhousing weep hole the clutch would by now be slipping and spinning like a politician's shiny promises.

Depends.............If it`s the main seal that`s leaking the oil would follow the rearside of the basket and be thrown off.
When the O-ring at the center nut getting old and brittle.......the funny tacho readings follows soon.

ReneZ wrote:Dave, how far did you fill her up?? Experience shows that putting in more oil than mid-level in the sight glass gets it burned up rather quickly, after that it stays there (mid level;with a good bike). Don't go by the amount in the book, fill her until the red dot/mid level in the sight glass. Further it can take different amount of time until all oil is back in the sump, so leave it for some time before you check. The 1100's are known to use some oil, but the 1000's and 750's rarely do, even the high mileage bikes.

Thanks Rene. It was up to the dot when I bought the bike and has stayed there since although it being wonter I've done very few miles. I then rode 130 miles to my mates this w/e and it had fallen so just visible in the sight glass. I checked and rechecked, in the evening but nothing. The next day I ran the bike for 10 mins on the mainstand and then left to stand for an hour - although it went up a bit - it was visible in the sight glass - perhaps about 3 mm up it, there was still some missing. I topped up with my mates oil and rode home 130 miles and now it is sittting at the red dot. Odd...

There can't be much coming from the bellhousing - it would be everywhere surely? There's just a few stains/drips on the bellypan.

charlie99 wrote:dave ,,,just as a comparison

heres one i exchanged out recently ..



i concider mine runs a little rich ...and most of the work it has done was with leaking throttle body rubbers and is just after the rubbers fix by about 200k trip home ...i recon they have done in excess of 25,000ks of service

i guess in time if i can borrow an gas analyzer and get the mix better , that would be good along with an engine overhaul ,,,replaced valve stem seals ...valve grind and rings ...etc ..

Thanks Charlie. It's useful to have some comparison, thanks. I've had a long break in home mechanics and have forgotten what 'normal' is.

since mooving to unleaded fuels the normal stuff that i grew up with doesnt seem to apply ...

but then again i havent bought a new engine in decades either

Hi Dave,
When checking the oil level, as you are, it's best to park the bike in exactly the same spot for each check. The slightest difference in gradient makes a big difference to the level at the glass.
Cheers,
Paul.

Hi Paul

Good to hear from you. Thanks, for sure I will keep this in mind, it removes one variable anyway!

Best
Dave

Keep in mind that it's only about a 1/3rd of a litre from near the bottom to the top of the sight glass. My bike 'finds' its own level after an oil and filter change. I usually get carried away and go just past the middle of the glass and it settles down to just below the centre after a few hundred kms, then I don't have to add a drop between changes. For example, two years ago I rode right round the edge of OZ, about nine weeks and 15,000 hard kilometres. I changed the oil and filter midway. I'd brought along a spare litre 'just in case'. I never used that spare oil...even in local, stop and go commuter riding, she drinks nothing.

Hi Guys,

Ebay is full of compression testers! Can anyone reccomend a cheapish one that they've perhaps used and that has the correct adaptor for a 'K'?

Much appreciated
Dave

If it's the push-in variety you'll have no worries because the rubber tip accommodates the spark plug thread size - though that sort isn't the easiest to use as they require three hands to accomplish the task. If it threads in it only needs to be able to do 14mm and 12mm threads to be about universal for all BMWs bar the newest K12/1300 series.
Too easy.

Be careful what tester you get on ebay most of them say you will need an adapter for your plug size.

Thanks for the advice Guys. Got a gauge with the correct thread size. Ran the bike from stone cold for maybe 2 mins then took some readings:

After 2 minutes running all cylinders had a reading of 95 psi.
Immediately afterwards and without running the bike any more I added a squirt of oil in the bores and took the following readings (psi):

1. 155
2. 125
3. 125
4. 115

So looks like the rings are worn ? EDIT Or do I need to warm the bike up thoroughly before taking the initial readings?
If the rings are worn what are my options for fixing it?

Thanks
Dave

PS. This is the compression tester I got - £20. Bergen 8 piece: includes adaptor that fits our engines plus several more. http://www.ebay.co.uk/itm/280838648874?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
Easy to use and pretty well put together.

I'm a bit puzzled. The plugs you showed earlier were quite OK and now you have these black plugs. What did you change to your settings meantime?
Also, how did you run the engine before you pulled the plugs? Both times the same? As if you ran it on lower revs for some time before pulling them they won't be representative for normal running.
Further, what do you mean with your wet and dry readings? You say you took the first ones after running the engine for a few minutes? Then that would be a 'wet' condition for me as the oil will have lubricated the liners/pistons quite well.

Rene
Thanks, I've edited the previous post as I confused you and was confused myself! Think the black plug was probably just black from open choke to start the machine so not representative of anything. I have therefore removed the picture and reference to it.
Best
Dave

OK, good one!

I wouldn't focus too much on the (potentially) worn rings. Bikes have been opened up after 250K and you could still see the honing marks from new, that's how hard this nikasil layer is. I'm not saying that it couldn't be your issue, but it rarely is.

I have noticed myself that if I drive faster and particularly on twisty roads (A86!! YES) the bike tend to use some oil and I have the feeling it comes from braking a lot on the engine. My friends at times remark that I brake so little, but these bikes really brake on the engine if you close the throttle.

Personally I would only worry if it continuously uses oil, which mine doesn't. I had it the other day when after a trip I noticed the level at the bottom of the sight glass, filled her up until the half way mark, started the engine and half an hour later the level was at the top of the sight glass.............

Dave warm it up to a normal temp by taking it fr a ride then do the test over again if the oil brings them up that much your rings are shagged or possible the lining but that is unlikely as the only one I have seen with bad liners was because of bad detonation over a prolonged period.
Solution either new rings or the cheapest is to get a good running engine and replace the present one. A set of rings and gasgets will cost more than a secondhand engine Ask me how I know BTDT

Thanks Rene/Rick

This morning I took her for a run - what a perfect day - blue skies for the first time in about 2 months and no-one on the roads, it being early on a Sunday!

Anyway, took readings when I got back. These readings were different in two ways to yesterday's;

1. The engine was warm
2. The throttle was wide open - yesterday it was closed.

The readings were (psi)

1. 150
2. 150
3. 145
4. 150

I therefore joyfully conclude there is sod all wrong with the compression.

I have to blame in part the English translation of the Chinese instructions that came with the kit that did not clearly explain that the throttle needs to be open; I picked this up after trawling the internet. For anyone who, like me is learning as they go this is critical - as an example I took another reading on cylinder 4 immediately after I got the 150, above, but with throttle closed and got 80.

So, I'm going to do an oil and filter change and see how she goes.

Interesting Rene that you mentioend engine braking perhaps burned a little oil; there was a lot of this on my run last week - going over Tomintoul and the Lecht it's steep and twisty for the most part.

Best
Dave

Dave, you live in bikers heaven!!

We have rented a house in Aviemore a few times for a week, making daytrips from there, beautiful part of the country. Once I have the bike back together I'll be up again, recharging the battery!! Ishould share some routes with you. Let me know where your house lives ;-)

Enjoy!