Forum

[ric]

It's taken REI quite some time to eventually realise that the tyre pressures they've been quoting in the handbook (that incidentally may have been correct at some point halfway through the last century) needed updating to match the requirements of tyres made with totally different compounds, processes and technology that are currently used by tyre manufacturers of today.
Is it in some way even remotely possible the same might apply to their lubrication schedule? If they're still even around producing the Bullet halfway through the next decade perhaps we'll find out

[AndyMc]

Thanks Ric, i've increased my vocabulary by 1 word stoichiometric, i just need to find a way to slip it into everyday conversation
Have a good trip to Europe, where are you going?
Andy

[Rattlebattle]

Stoichmetric is simply the ratio at which fuel is burned most completely. Whilst it is true that the ECU on bikes fitted with an O2 lambda sensor will endeavour to maintain the mixture to stoichmetric (around 14.7:1 air:fuel for petrol) so as to minimise exhaust gases, Dynojet et al make a living by selling aftermarket products such as Power Commanders. These essentially alter the air:fuel ratio to obtain optimum power, which for petrol is closer to 13:1. So if the fuel mixture is set for power rather than complete burn, the mixture will be richer and the impact on oil quality as the engine is run will be affected adversely, though probably not to a large extent. An easy way to establish the condition of oil is by how much the colour of the oil changes from a nice golden colour (or red) to a murky brown or black. Anyone who has a classic bike running on mineral oils will know how soon this happens after an oil change. Old Brit bike usually ran rich, especially at tickover. As I have fitted a carb to my C5 the oil blackens fairly quickly which is one of the reasons I change the oil annually irrespective of mileage, within reason. It becomes acidic as it is contaminated by the by-products of combustion, especially if the fuel is not burned completely. Semi-synthetic oils usually have a mineral oil base; fully synthetic oils are much superior and last longer - the choice between longlife and annual oil change regimes in the car world, such as VW dictates which type of oil is used, semi or full synthetic. Like I said, in my opinion those who use their bikes regularly and for decent mileages per ride can safely leave oil changes longer than those, like me, who only ride occasionally and for short distances (on my C5). BTW ethanol has a stoichmetric ratio of 7:1 or thereabouts. 10% ethanol in petrol (and I use the term loosely) equates to a 7% weaker mixture, which is why some engines run better on non-ethanol or 5% maximum ethanol fuel (ie 97 Octane which so far cannot contain more than 5% ethanol in the UK). The O2 sensor causes the ECU to drag the mixture back to stoichmetric for petrol, so compensates for the ethanol, but what if you have a carb, or a Power Commander? Neither can determine what fuel is being used......

[macg4]

Related query-since we are chewing the oily rag..Where does the forum stand on the use of engine/fuel additives?

[papasmurf]

macg4, all my wife and I's motorcycles have had Wurth petrol and oil additives for a long time now.
(As the mechanic states, it saves him many hours on carburettor and injector strip downs and curing oil leaks that are O-ring based.)

[Andy M]

If PTFE etc. did any good the oil companies would be using it. While motorcycle oil is toy town stuff sold by claiming brand X has added citroenium for a zesty performance, commercial oils are actually analysed by the big fleets. Snake oil IMHO.

Andy

[Rattlebattle]

I've had a few new bikes in the last few years since semi and full synthetic oils have been on the market. The manuals nearly always advise against additives. I follow that advice. I used to add molyslip to the rear bevel drive on a Moto Guzzi I owned, but that was advised by M-G. In the current edition of MCS&L there is an advertorial on Liqui Moly, which apparently is the official partner of Moto2 and Moto3. Their part synthetic and full synthetic oils appear to contain molybdenum (disulphide?). More interestingly their range includes "shooters" i.e. Fuel additives designed to clean the engine and increase acceleration (and no doubt wash the bike and pump the tyres up...). Apparently it's a best seller in mainland Europe. I think I'll wait and see ....I use Redex myself, as appropriate for a carb or EFI. I still have some of the old good stuff for carbs. I once did the treatment on a Metro, squirting in the plug holes and carb inlet. It smoked like a destroyer for twenty miles...Ran great afterwards though..

[macg4]

To be honest I am more inclined to use the odd tankful of higher octane fuel which allegedly contains cleaning agents. Although I still remember the craze in the mid-eighties for 'enhanced' fuels,and the ensuing valve damage.Is it preventive maintainance or a case of 'if it aint broke- don't mend it'..REgards.

[Leon Novello]

Friction modifiers do work; if added to a synchromesh gearbox the clutch/cones will slip and the will not synchronize the gear speeds resulting in it becoming a crash box where double de-clutching is necessary to obtain a quiet gear change until the oil can be changed and the box flushed. I am not telling how I know this.

[ric]

AndyMc
Two bikes, self and wife, travelling around France then into Spain, probably via the Pyrenees, then heading West towards Portugal. Itinerary is very loose but basically it's three weeks of bimbling around sightseeing in the warmth(hopefully) and averaging 200 miles a day at speeds of not more than 80kph.
The bike has been tweaked a little since last years trip so averaging just under 100mpg probably isn't going to happen again but the improvements should make the uphill mountain sections a little easier.
,BR> All being well on this trip we'll be heading over to Northern Italy to ride around the lakes later on this year.