Hi People,
Long time since I last posted but I've put a few more miles on the rebuilt 550 recently and am up to a modest 600 now! All good and very satisfying, apart from ongoing concerns about gearbox oil contents but I've learnt from other bikes that too much oil will always leak out from who-knows-where, so maybe that's a non-issue.
My question is can one back off the engine oil pump when using Motorex fully-synthetic oil? I suspect that the answer will be to leave it on stock setting as per the manual, but I have a horror of seeing a blue haze behind me when I open the throttle for a quick blast. Not that I've gone beyond 5.5Krevs yet, of course. Considering how premix ratios have changed over the years since our bikes were built, surely the clever oiling systems we enjoy can be adjusted accordingly?
Cheers,
Nick in Norfolk
Oil pump setting on synthetic oil? '76 GT550
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malky
- Posts: 1098
- Joined: Sat Dec 19, 2009 3:25 pm
- Location: swansea south wales
Re: Oil pump setting on synthetic oil? '76 GT550
I turned my pump down a bit on my kettle using modern mineral oil and its been fine for years - still smokes a bit though when I give it the beans , my T500L on the other hand running on fully synthetic and normal oil pump settings doesn't smoke at all no matter how hard its ridden
Mal.
Mal.
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asco58
- Posts: 122
- Joined: Sat Nov 21, 2020 2:24 am
- Location: London
Re: Oil pump setting on synthetic oil? '76 GT550
You should leave the oil pump at its stock setting. The engine requires a specific volume of oil flow to maintain an acceptable level of lubrication to prolong the engine lifespan. I wouldn't recommend it while breaking in the engine either.
Anyway, On a stock setting the bike should be smoking less on synthetic anyway compared to mineral oil but these bikes will always smoke above a certain RPM, maybe 4000 rpm or something. The bikes are designed to reduce smoke at idle and cruising around town but if you open the throttle wide enough the rate of oil flow increases quite steeply so it will always smoke more on hard acceleration.
It's true that premix ratios have changed over time and are now as low as 80:1 or 100:1 but in order to do this, the manufacturer has to design the engine with that ratio in mind and perhaps adapt cylinder/piston clearances, cooling systems etc to cope but even then it is likely the low amount of oil is much closer to if not pushing the limit of the minimum amount of lubrication needed to run the engine. It's largely about meeting emission standards.
Anyway, On a stock setting the bike should be smoking less on synthetic anyway compared to mineral oil but these bikes will always smoke above a certain RPM, maybe 4000 rpm or something. The bikes are designed to reduce smoke at idle and cruising around town but if you open the throttle wide enough the rate of oil flow increases quite steeply so it will always smoke more on hard acceleration.
It's true that premix ratios have changed over time and are now as low as 80:1 or 100:1 but in order to do this, the manufacturer has to design the engine with that ratio in mind and perhaps adapt cylinder/piston clearances, cooling systems etc to cope but even then it is likely the low amount of oil is much closer to if not pushing the limit of the minimum amount of lubrication needed to run the engine. It's largely about meeting emission standards.