Eating oil

[skiri251]

Went out for one night camping trip with my son and just came back.

357 miles of mostly freeway ride.
(I-110, I-405, I-10, PCH, I-101, CA-154, I-101 to Santa Maria and back).

Before the departure, I filled engine oil (to around 5/8 full in the sight glass).
After 357 miles, I cannot see any oil in the sight glass.

I have been noticing excess oil consumption these days.
Topped up the oil in the sight glass and after 300 miles or so, it drops to 1/3 full.

I don't think the engine is smoking badly. I looked at it when idling. I don't see trail of smoke in the rear view mirror on the freeway either.
I thought the leakage from the damaged drain plug is the major cause. But this time I wiped oil clean around the plug and put RTV silicone. No sign of leakage there but still this much consumption.

What should I do?
New piston rings?

The last time I checked the compression (a few years, couple thousand miles ago), the numbers were within the spec.

 

[Ansimp]

Sounds like you might be overfilling and they will consume oil if that is the case, oil control is hard in a flat motor so level can be critical. If it was mine I would take oil with me on the next trip and not fill it past the 1/3 mark ( which is just shy of the half mark which I find is full on the Rats Nest) and see if you need to top up. If you don't have signs of burning oil and the compression is still good then I don't believe that you have anything to worry about :yes:

 

[skiri251]

Well, I filled it to 5/8 (a bit more than half) then 357 miles later I see NO oil in the sight glass so I don't think I am overfilling.
I have been parking her on the center stand lately so that no oil goes into the left cylinders so no start up smoke either.
I will do the compression test again but the engine runs great..

 

[zman]

It probably isnt this but a small drip from the shift seal will usually burn on the pipe and not leak further but you would notice the smell and a puff of smoke at start up off the pipe. I would add 8-12 oz of marvel mystery oil and see if it loosens up a sticking oil ring, I suppose if your guides were bad enough and your stem seals were shot that would account for some, need to ask someone to ride or drive behind to observe your exhaust stop light to stop light.
One thing I do know is it is either burning it or leaking.

 

[sgq700]

my 1980 engine did that, 1 qt every 300 miles(or every 2 round trips to work) and i didn't realize that mine smoked as at a idle, no smoke and only once in a while on start up! but when riding with a friend one day,i twisted it on pretty good and he told me i looked like a fog machine? The 83 motor i run, i fill to the top of the sight glass and after 3000 miles i still see oil 1/4 from the bottom. my 80 engine also ran great, just liked oil!

 

[Terry]

I would think you that you could see and smell that much oil consumption. My 82's oil level never discernibly drops level in the sight glass, but it only has 30K miles on it. I just made a 350 mile trip, checked the sight glass and it's exactly where it always is. Maybe it needs rings if it's very high mileage bike.

 

[Tom_Charlton]

pull the spark plugs. Consuming a quart every 300 miles should show carbon buildup/oil on the plugs. While the plugs are out, do a compression check. If the compression is still on the money, your oil rings or valve guide seals need replaced. Hope for the valve guide seals because you can change them without pulling the motor.

 

[Ansimp]

I have had Subaru's that consumed oil from 100K klms and have run perfectly for another 200K klms before getting tired. One ea81 engine I had rebuilt at 160K klms and after it didn't use any oil but it also didn't rev as hard as before it was rebuilt. I ran one engine with modified oil control ( purge tank) until it was using a litre of oil per 200 klms and it looked like a steam train before replacing the engine (ea82) :smilie_happy:

 

[slabghost]

I'd try running 1/5 of the oil capacity with atf. Might clean up enough gunk to reseal the rings and valve seals.

 

[Tom_Charlton]

+1 on the ATF. Just remember you have effectively thinned the oil and adjust your riding style appropriately

 

[skiri251]

Thanks every one.

Mine got 47K on the odometer.
Shift shaft seal was replaced and no leak from there.

I will check the compression then try ATF or MMO (also in the engine, not in the fuel tank, right?) and see what happens.

 

[Omega Man]

There's no telling if that is the original speedo. :read:

 

[skiri251]

Omega Man » Mon May 18, 2015 7:39 am[/url]":1azjpfyi]
There's no telling if that is the original speedo. :read:

Right. I am aware of that.
This was supposed to be Aspencade but when I bought her there were no radio, intercomm. Instead cooked up covers with vents.
Or simply she had been badly maintained.

 

[slabghost]

skiri251 » Mon May 18, 2015 8:10 am[/url]":1y60ti5w]
Thanks every one.

Mine got 47K on the odometer.
Shift shaft seal was replaced and no leak from there.

I will check the compression then try ATF or MMO (also in the engine, not in the fuel tank, right?) and see what happens.

ATF in both fuel and oil will keep everything clean and moving smoothly.

 

[skiri251]

Did the compression test.
Engine fully warmed up, all plugs out, throttle wide open.

1 RF: 170
2 LF: 175
3 RR: 175
4 LR: 170

plugs look okay.

Added ATF to the engine oil.

How many miles should I ride with ATF?

 

[Ansimp]

Not much oil hitting those plugs :good:

 

[mcgovern61]

Take a look at your back cover and look for any oil smears. I am under the opinion it is leaking.

 

[skiri251]

mcgovern61 » Mon May 18, 2015 6:50 pm[/url]":2kj9ey34]
Take a look at your back cover and look for any oil smears. I am under the opinion it is leaking.

Is that a clutch cover?
I looked around yesterday but didn't find any sign of significant oil leak. Unless it's burned immediately and doesn't leave any trace.
Clutch cover was clean.
I saw some oil/dust mixture around exhaust headers but hard to imagine that accounts for a quart or even a pint of oil..
No trace of oil on the floor since I tightened thread-damaged drain plug a little and put RTV silicone around it.
If it leaks under pressure, where else can it be?

 

[mcgovern61]

If it leaks under pressure, where else can it be?

Hmmm.....have you checked and/or emptied your blow-by bottle? (Located on the left down by the centerstand.) Be sure it is not full of water or oil.

The only other external possibility I can think of is the cam cover seals. Look up under the front timing belt covers and then back towards the head/exhaust. Lastly, run a finger under your oil pan and see if it is remotely wet (oil plug or oil filter seal).

 

[skiri251]

mcgovern61 » Tue May 19, 2015 6:11 am[/url]":2i9y9rog]

If it leaks under pressure, where else can it be?

Hmmm.....have you checked and/or emptied your blow-by bottle? (Located on the left down by the centerstand.) Be sure it is not full of water or oil.

The only other external possibility I can think of is the cam cover seals. Look up under the front timing belt covers and then back towards the head/exhaust. Lastly, run a finger under your oil pan and see if it is remotely wet (oil plug or oil filter seal).

Blow-by bottle is not used since the single carb mod.
I have a mini pod filter connected to the crankcase breather. No sign of oil there either.

Oil pan was covered with oil before. That was due to oil leak from the drain plug. But that was fixed before this 357 mile trip and again no sign of leak afterwards.