Sally (SRX600 1JK) burning oil! What's up?

[themoudie]

About 1,000Km (620 miles) ago and with about 74,000Km (46,000 miles) on a rebuilt, using a Wiseco cylinder liner and piston 'standard' bore 598cc kit for a Grizzly quad engine, I made a 4,000Km (2,500 miles) oil change using a Yamaha filter and Halford's 10/40 semi-synthetic motorcycle oil, as I had misjudged my stocks of Morris 10/40 semi-synthetic motorcycle oil in the 25litre drum. 

Two litres of Halford's 10/40 semi-synthetic motorcycle oil went in the tank and because the level was a little (100cc) below the upper mark on the dip stick a wee drop of Morris' 10/40 semi-synthetic motorcycle oil to bring the level up to the mark. A shaky hand meant that I was a wee bit over the mark and thought nothing of it.

Immediately after the oil change we went for a tour of the Angus glens (130 miles) and on a closed throttle going down steep hills it looked as though I had a Bantam under me!    Kat was spluttering in the fumes, but performance didn't appear impaired and I thought that once the excess oil was burnt off all would be fine. There followed another two canters on my own (400 miles) and I didn't notice anything untoward in the mirror and the oil level was within the safe range on the dipstick.

Yesterday, we had another pootle about into Fife, with some steep descents on a closed throttle and low and behold the 'Bantam' syndrome returned!    Apparently, it also manifests itself depending on which way the bike is lent over after going through roundabouts and a series of corners!    When we returned home, I again checked the oil and the level was now sitting just above the lower safe level on the dipstick and required 250cc of Morris' finest to bring it up tothe upper level. I don't regards this as excessive oil consumption for a run-in 600cc 4 stroke single.

Have I popped the valve stem oil seals by over filling at the oil change?

With 46,000 miles on the bore am I starting to get a bit of 'blow by' past the bottom (oil control) ring on the piston?

Is it Halford's 10/40 semi-synthetic motorcycle oil?

May I ask Andrew and Michael if they noticed anything aromatic or hazy from the exhaust on our run through Galloway? I'll no rephrase that and understand the inuendo!    I gave it up for Lent many years ago! 

I don't intend to do anything about the reek yet, but suspect that I am going to find general wear and tear on the bore and maybe a 'popped' oil seal or two, requiring a top end rebuild along with a hone and a new set of rings. It just makes me wary of the lubricity of Halford's oil!   

My regards, Bill

[Propellor]

Didn't notice anything of that ilk Bill. Would have let you know if so.

No chance this could be getting sucked back in through the airbox? The closed throttle symptom does sound ominous though.

Another long shot (very long!) I noticed you have a scottoiler. No chance it's pulling oil up from there?

[themoudie]

Aye Andrew,

I don't think that either of those possibilities are the culprits, but thank you for the thoughts, I will give them a wee looksee.

My regards, Bill

[Moto63]

No... me neither Bill. I didn't notice any thing untoward on our ride out with you. Hopefully you can get to the bottom of it and without it costing you to much time, effort and money 🤞
Cheers, Michael

[johnr]

ok so its smoking on thee overrun, your options are that its drawing it in to th cylinder through a damaged head gasket, the breather is blowing it into the airbox, the bore is letting oil by th piston or the valve stem oil seals on the inlet valves are letting oil by. as the stem seals are likely to be getting on, id be tempted to look at them first.
pull out the air filter and check that the airbox hasnt got oil in it. if its ok, thn off with the carbs and have a look to see if the inlet valves stems are wet with oil. only other thing could be that the bore is glazd and you need to hone it to break thee glaze.

[themoudie]

Aye morning John,

Thank you for the sequenced run down that follows my train of thought as well. Last time out there was a bit more of a rattle, tappety noise than usual! So, the old bird is sitting in the garage awaiting surgery. The Mono tinware having now returned from the painter and my paranoia at running in engines after rebuilds, means that Sally may be a wee while.

Furthermore after an absolutely sh1** weekend, yesterday was a really nice day and so I took the Boy Bros out for a canter around Fife to St.Andrews and then home. A very enjoyable run and a very different wee beastie from the singles, smooth, turbine like motor and a gearbox that really is like a hot knife through butter and now nearing 80,000 miles, with just regular oil and filter changes.

Likely to post Sally's ailments on here, as we go.

My regards, Bill

[Propellor]

Good luck Bill. Look fwd to your updates
 

[Steve Lake]

That's a strange one Bill !.... sally burning oil I'm referring to :-) . reading all the posts it would seem that all options are covered...
however... I note that you say the 'bantam' experience is more noticeable following cornering ,   and that could be , just maybe 'wet sumping' ? that stupid bloody stupid (now unobtaneum) filter tray being partially blocked. or the sprung loaded non return valve being stuck open, or possibly your new filter not performing (do you get a good strong spurt from the bleed screw hole ?.
I've used Halfrauds oil on #1 for as long as I can remember (changing oil & filter at 3K tops) with no problems, also, on quite a few occasions overfilled (as the is no mark on my temperature dial stopper thingy.) so it's always a guestimate.
good luck