Warm up first?

[Kalessin]

The SV manual says

Allow enough idling time after warm or cold engine start up before revving the engine or placing the transmission in gear. This allows time for the lubricating oil to reach all critical engine components.
but Sid Squid says (http://forums.sv650.org/showpost.php?p=1792782&postcount=2)

Don't leave your bike to warm up - start it, ride it. Warming up is all deficit, no benefit.
When I bought my bike, Midlands Superbikes said

Let the temperature gauge reach 50° before you ride off.
I tried to find a happy medium. I tend to let the bike warm up to 20° and ride away, but avoid hard acceleration until 50°.

What do you think is best?

[zsv650]

your thinking too much i just start put my gloves and helmet on then sod off i guess the way suzuki say would be the one to trust.

[Lissa]

Warm it up a bit. Start it, then put helmet and gloves on. Zip up any fleece pockets that may contain wallets :D

Then ride it gently until it hits about 50/60 IMO. Gives you a chance to warm the tyres up then too.

[fizzwheel]

I tried to find a happy medium. I tend to let the bike warm up to 20° and ride away, but avoid hard acceleration until 50°.

What do you think is best?

what you're doing is reasonable, I tend to do as Lissa says, Start bike, put on gloves and Lid, then ride away and dont cane it till its nice and warm.

[ogden]

I always let my bikes warm up before riding but a lot of that is down to what I ride. I tend to be the same with my car, but that's mostly because of the turbo.

With the thou, I start it in the garage, then unlock it and wheel it out, kit up and by then the temp gauge is already around 60 degrees (even at this time of year) so it's ready to ride.

With the RGV, I spend about 20 minutes getting the damn thing to start and then about as long again waiting for the temp gauge to even hint at moving. But that's special so I don't mind. The alternative is an engine rebuild.

A modern 4-stroke bike engine takes, what, five minutes of idling to get up to 50 degrees or so? By the end of the road it'll be at 60 and then you're into operating temperature. I know time is money but c'mon.

[embee]

You really don't do it any favours by leaving it idling for prolonged periods from a cold start, it's contaminating the oil film on the cylinder bores with fuel and condensation, which reduces the service life of the oil and increases wear rates on the rings and bores. Also idle is about the worst condition for valve train wear.

Start it, let it settle for a short time for the afterstart enrichment to ramp down or just long enough to get the choke off, typically no more than 30sec is needed, then ride off gently.

As said, gradually ease the revs and load up while it warms up fully before using high power/revs.

[daveb]

Wow, 50 degrees! That must take a while - I always leave mine ticking over till the temp gauge starts to register which is usually 20 degrees, then I'll ride off, this is what the dealler suggested.
50 degrees does seem like a long time tbh - as long as the oil has had a few minutes to circulate then it should be fine as long as you don't overload the engine until it's decently warm.

Ogden, what's the issue with your RGV? I always used to start mine and leave it ticking over for a few minutes then gently start to increase the revs until the engine started to warm - leaving a stroker to idle for too long without revving it can cause coking up which wont do the exhaust valves any good in an RGV...

Just my 2p

D

[ogden]

Ogden, what's the issue with your RGV? I always used to start mine and leave it ticking over for a few minutes then gently start to increase the revs until the engine started to warm - leaving a stroker to idle for too long without revving it can cause coking up which wont do the exhaust valves any good in an RGV...

Damn thing won't start without a squirt of Easy Start. I suspect a choke problem but investigation so far has turned nothing up. Once it's warm it's an absolute peach, 55 at the wheel.

A 250 stroker doesn't generate a lot of heat at the best of times (luxury for commuting to work through London in the summer, mind) so it's not going to warm up quickly and you know how badly strokers react to being revved before they're warm enough, that throaty stuttering.

I take a sanguine view to warming up - it takes ages, but I manually take the revs up to 3k or so to help it along. There's revving and there's revving, but if the choke was doing its job that's where it'd be anyway so it suits me. It was at Dave Cooper's a couple of years ago, if I can find a cheap set of Arrows I may throw it his way again to sort out the fuelling and the starting but until then I'll make do.

[ogden]

Oh, PS, the 20 minutes getting it to start it something of an exaggeration. After all this time I've got the whole seat-off tank-off squirt-in-the-airbox thing down to under 5 minutes but in full winter kit it feels like more than 20. Grumble grumble grumble.

[Stu]

You really don't do it any favours by leaving it idling for prolonged periods from a cold start, it's contaminating the oil film on the cylinder bores with fuel and condensation, which reduces the service life of the oil and increases wear rates on the rings and bores. Also idle is about the worst condition for valve train wear.

Start it, let it settle for a short time for the afterstart enrichment to ramp down or just long enough to get the choke off, typically no more than 30sec is needed, then ride off gently.

As said, gradually ease the revs and load up while it warms up fully before using high power/revs.
Thanks :D
I get fully ready before starting, then pull away once settled in 5 secs then switch off choke as soon as I'm riding.
Try not to use many revs until it's warm is the only concession I make :)

[muffles]

No one here has an oil temp gauge as well do they? If you've only got one temp reading it's a 99% chance it'll be your coolant not your oil. Oil takes a lot longer than coolant to warm up...and is the important one...

[Biker Biggles]

Thanks :D
I get fully ready before starting, then pull away once settled in 5 secs then switch off choke as soon as I'm riding.
Try not to use many revs until it's warm is the only concession I make :)

I also ride off as soon as the bike will go without stalling.

[Larry]

I let the bike run until it idles with no choke, then I ride off gently for 5 mins or so before raising the revs a bit.

[ThEGr33k]

Warm it up by starting leaving for 30 seconds then holding it at full throttle on the rev limiter for 32.3 seconds... All warm. :D

Ok no that's bad... It would be warm, but also ever so slightly knackered :(

Start and ride tbh.

[BBadger]

start it, ride it slow and easy till it reaches 50 odd and riding that only takes a min or two so youve got nothing to worry about.

[thefallenangel]

was told by someone i'd trust with engines "Any engine half revs until up to temperature is fine". Safe to say his Audi A6 is at 180,000 miles and hasn't missed a beat although his wing mirror is broken.

[suzsv650]

2 Stoke defo needs warming and for a long time....

SV not so much

I usually leave the the R6 about 1-2 mins then ride crarefully

[SVGrandad]

Engines warm up faster with a bit of load on them, so fire them up and run them gently for the first few miles. Once hot, ride normally. Oil needs to get hot to boil off condensation etc, so riding too gently for the whole journey is not good for it either, but I dont suppose that applies to anyone on this forum!

[Miles]

You really don't do it any favours by leaving it idling for prolonged periods from a cold start, it's contaminating the oil film on the cylinder bores with fuel and condensation, which reduces the service life of the oil and increases wear rates on the rings and bores. Also idle is about the worst condition for valve train wear.

Start it, let it settle for a short time for the afterstart enrichment to ramp down or just long enough to get the choke off, typically no more than 30sec is needed, then ride off gently.

As said, gradually ease the revs and load up while it warms up fully before using high power/revs.

That's what I've always been led to believe.

At idle it takes longer to warm up and oil pressure will also be lower.

As long as you take it easy for the first few miles, and dont show it the redline until the oil is properly warm then I shouldn't worry.

[xXBADGERXx]

Thanks :D
I get fully ready before starting, then pull away once settled in 5 secs then switch off choke as soon as I'm riding.
Try not to use many revs until it's warm is the only concession I make :)

I thought you had a pointy Stu ? Auto-Choke on them or have you rigged something up ?

Throughout the ownership of my bike I have done this :

Put jacket and trousers and boots on , go outside and start bike , unlock chain , zip jacket and do lid up , throw gloves on , back it out of driveway and then pull away . No more than 2 minutes tops to do all that . Run the bike for about a mile to the A55 at no more than 5k revs and then when I hit the A55 I don`t go past 7k revs . Once I am onto the fast bit of the road the bike is nicely warmed up and I am happy to give her a bit of a Toot on the way to work .

[dizzyblonde]

Depends on time of year. Summer choke on, ten seconds if that. Winter, up to 3 thousand revs for about 20-30 secs ( enough for me to lock the back door and open the gate) choke off, away we go:p

Also depends on which bike in our house. The SRX takes ages before its warmed up. The Raptor has to be upto 30 degrees before it even goes anywhere, its an Italian pedigree, they have to be treated proper like;-)

[Stu]

I thought you had a pointy Stu ? Auto-Choke on them or have you rigged something up ?
.
Still got the SV, but all my riding is now on my ZX6R :D

[xXBADGERXx]

When I saw that in your signature mate , I assumed it was GSXR front end with ZX6R rear end ........ doh!!!!!!!

[MattCollins]

....Winter, up to 3 thousand revs for about 20-30 secs ( enough for me to lock the back door and open the gate) choke off, away we go:p

That is the right way to ensure oil gets up into the motor quickly, although I would give it at least 30s during the winter. During the summer months I would be giving the motor 20-30s. Warm motor that has been standing for a while is the same. Start and gently raise the rpm to a constant level without "revving" it.

Also oil pressure lights can be a little deceptive. I am unsure about the SV so I treat it as a worst case. Many are set to blink out at zero, or pressures that are way to low. Their location also means that they can be a poor indicator of adequate lubrication in the far reaches of the system.
One of the worst things that can be done is to hit the starter and pop the clutch as is often done. That seriously shortens the life of a motor.

Startup is all about lubrication... warmup is done on the road, but a couple of minutes idling certainly won't hurt anything. A lot comes down to what the rider does in those first couple of miles before everything is up to temperature. I just ride it easy and keep it below 4.5k and half throttle.
Something that I will not do is a cold start to ride 1/2 a mile to the corner shop. Both the bike and I benefit more if I walk.

I tried to find a happy medium. I tend to let the bike warm up to 20° and ride away, but avoid hard acceleration until 50°.

What do you think is best?

I'd be happy with that, although I would bump the rpm for the first 30s or so.

Cheers

[skyline]

When I start my bike I try to use the choke to keep the revs between 2000 - 2500rpm instead of 3000, I'd heard that too high rpms on the choke can foul the spark plugs...

[dizzyblonde]

3000 is hardly high on the choke. Never had any problems with spark plugs fouling from how I warm up my bikes....I've been doing it for 5 yrs on an SV.

[Nostrils]

I wheel the SV out, start it, light a fag, suit up, fag out, helmet and gloves on and away - because of the local roads being so beaten up I am slow until the dual carriageway and off I go.

[Sid Squid]

I stand by what I said, and the excellent and sensible advice from Embee, which all boils down to:

Start it, ride it. Warming up is all deficit, no benefit.

Clearly I'm not suggesting you spank it into the limiter before you reach the end of your street. My Enterprise mileage ZX6* suggests I'm onto something there. The several bikes I've taken right 'round the clock prior to this one suggests that's not a fluke.

[MCN_LiamM]

I don't follow any strict rules with warming up.

I generally get the bike out of the garage and go inside to get my gear sorted - leaving my helmet and gloves off.

Then go outside and start it while I put my helmet and gloves on. Off we go.

Not always possible though. This morning I turned it on and set off straight away 'cos it was 6am and I didn't fancy waing the neighbours

[Spokey]

I stand by what I said, and the excellent and sensible advice from Embee, which all boils down to:

Start it, ride it. Warming up is all deficit, no benefit.

Clearly I'm not suggesting you spank it into the limiter before you reach the end of your street. My Enterprise mileage ZX6* suggests I'm onto something there. The several bikes I've taken right 'round the clock prior to this one suggests that's not a fluke.
+1
it's all about getting the oil flowing properly round the engine and properly warmed up to working temperature as quick as possible. When you ride your bike as the components turn and move they draw oil between them creating a hydrodynamic layer which builds up a lubricant film between the surfaces preventing wear. Some engines can take up to 2 minutes before the oil has circulated properly round - also, riding your bike gets the whole engine warmed up, sitting idling is the worst thing you can do to an engine for the reasons Embee has already stated.

Spokey

[monkey]

...it's contaminating the oil film on the cylinder bores with fuel and condensation, which reduces the service life of the oil and increases wear rates on the rings and bores....

Can someone explain this to me please along with the enrichment thing? What is the function of the choke/FI alternative?

[zsv650]

chokes to spit a bit more fuel in aint it fi just does itself.

[jaffacakes]

I was told to leave mine for about 5 minutes! Cant be arsed with that, I usually wait till its about 30-40

[monkey]

chokes to spit a bit more fuel in aint it fi just does itself.

Yeah but why does it need to do it? What's the purpose of it?

[joshmac]

Yeah but why does it need to do it? What's the purpose of it?
Otherwise it'll just cut out if it's cold and the revs are taken away

[SVGrandad]

Yeah but why does it need to do it? What's the purpose of it?
A fuel/air mixture that is right for a hot engine will not fire in a cold engine hence the need for more fuel in the air for a cold motor

[monkey]

I know but WHY?!!! Why does the engine need more fuel in the first place? If it's because it's cold then what difference does it make?

EDIT: Sorry Grandad, I was still writing when you piped up!

[Spokey]

Yeah but why does it need to do it? What's the purpose of it?

Its purpose is to restrict the flow of air thereby enriching the fuel/air mixture while starting the engine.

Choke is required because small droplets of petrol don't evaporate well in a cold engine. By restricting the flow of air into the carburetor, the choke valve raises the level of vacuum inside the throat of the carb, which causes a proportionally greater amount of fuel to be sucked out of the main jet and into the combustion chamber during cold-running operation. Once the engine is warm, opening the choke restores the carburetor to normal operation, supplying fuel and air in the correct ratio for clean, efficient combustion.
Fuel injection bikes alter the amount of fuel / air ratio automatically depending on running conditions.

Oil is deposited in the honing marks of the bore as the piston goes up and down by splash lubrication - these act like tiny ledges to hold the oil which provides a lubricant film between the bore and the piston skirt, and a seal between the ring and the bore. Fuel can wash this oil away so you loose the seal allowing blowby into the sump which deteriorates the oil - and you get less protection of the bore by the oil as a lubricant which can wear away the honing marks and polish the bore - worse case scenario is no honing marks = no ledges for the oil = no seal for the rings = looses compression and burns loads of oil as it comes past the rings.

Also, if the top of the engine is very hot from combustion, but the bottom end is cold because it's not moving and warming up - this can cause condensation - the condensation mixes with the by-products of combustion and creates powerful acids that can damage the internal components. Also for every gallon of fuel you burn, you produce a gallon of water - only when your engine gets hot is this water burnt off ( that's why you get water out of a cold bike exhaust - which is why they tend to rot from the inside out )

I think thats right ...;)

Spokey

[Sid Squid]

It's needed as when the engine is cold the fuel in the intake charge falls out of suspension and recondenses onto the cold surfaces of the engine meaning that the mixture that reaches the cylinder will be severly weakened. You don't actually need a richer mixture to burn when cold - it's just a mechanism to ensure enough fuel actually makes it to the cylinder to ensure reliable burning when cold.
The 'choke' nowadays is rarely that, that term specifically refers to a plate upstream of the carb's jets, (that is; the air filter end of the carb), which when closed over restricted the air intake, such a restriction means a greater proportion of the resultant vacuum would act upon the jets, thereby increasing the fuel flow and richening the mixture. Sometimes the plate would be spring loaded, so that the vacuum couldn't rise too high - a high vacuum would pull open the plate against the spring, sometimes the plate simply had a small hole in it, close over for starting, open for running. Both are from the sledgehammer school of engineering.
Nowadays because of such history we have inherited the word choke, as in choking the intake, but it never is, it's a separate set of jets that flow fuel in a rather neater and more controlled way rather than the intake strangler it originally was.

[monkey]

That's what I'm talking about! Thanks clever people.

[SVGrandad]

Its purpose is to restrict the flow of air thereby enriching the fuel/air mixture while starting the engine.

Choke is required because small droplets of petrol don't evaporate well in a cold engine. By restricting the flow of air into the carburetor, the choke valve raises the level of vacuum inside the throat of the carb, which causes a proportionally greater amount of fuel to be sucked out of the main jet and into the combustion chamber during cold-running operation. Once the engine is warm, opening the choke restores the carburetor to normal operation, supplying fuel and air in the correct ratio for clean, efficient combustion.
Fuel injection bikes alter the amount of fuel / air ratio automatically depending on running conditions.

Oil is deposited in the honing marks of the bore as the piston goes up and down by splash lubrication - these act like tiny ledges to hold the oil which provides a lubricant film between the bore and the piston skirt, and a seal between the ring and the bore. Fuel can wash this oil away so you loose the seal allowing blowby into the sump which deteriorates the oil - and you get less protection of the bore by the oil as a lubricant which can wear away the honing marks and polish the bore - worse case scenario is no honing marks = no ledges for the oil = no seal for the rings = looses compression and burns loads of oil as it comes past the rings.

Also, if the top of the engine is very hot from combustion, but the bottom end is cold because it's not moving and warming up - this can cause condensation - the condensation mixes with the by-products of combustion and creates powerful acids that can damage the internal components. Also for every gallon of fuel you burn, you produce a gallon of water - only when your engine gets hot is this water burnt off ( that's why you get water out of a cold bike exhaust - which is why they tend to rot from the inside out )

I think thats right ...;)

Spokey
An excellent reply Spokey, but can you elaborate on the lubrication of Chrome plated bores - do these have honing marks to hold oil?

Sorry if I have hijacked the thread

Svgrandad

[Spokey]

Now that's a damn good question - honest answer is I don't know. same I suppose with Nikasil bores. I'll have a look into that one.

it's a big problem with diesel engines, the carbon in the oil can, if left and not changed enough, literally grind the bores smooth which polishes the honing marks away - you then get really bad oil burning and loads of smoke out the exhaust because the oil isn't sealing the rings.

Spokey

[SVGrandad]

The 'choke' nowadays is rarely that - it's ordinarily an enrichment device, rather than the intake strangler it originally was, and the reason for why we have inherited the word 'choke',
It's needed as when the engine is cold the fuel in the intake charge falls out of suspension and recondenses onto the cold surfaces of the engine meaning that the mixture that reaches the cylinder will be severly weakened. You don't actually need a richer mixture to burn when cold - it's just a mechanism to ensure enough fuel actually makes it to the cylinder to ensure reliable burning when cold.
Mr Squid, why should the fuel droplets recondense on cold engine surfaces? I would have thought that the temperature of metal in a cold engine would be the same as the fuel temperature, so you would not get condensation as such. I have always assumed that a hot engine raises the volatility of the fuel and makes it easier to ignite, but would welcome correction.

SVGrandad

[Sid Squid]

Mr Squid, why should the fuel droplets recondense on cold engine surfaces? I would have thought that the temperature of metal in a cold engine would be the same as the fuel temperature, so you would not get condensation as such. I have always assumed that a hot engine raises the volatility of the fuel and makes it easier to ignite, but would welcome correction.

SVGrandad
You're absolutely right of course - when the whole business is hotter things are lit somewhat easier, but essentially the fuel mixture is referred to as an emulsion; a mixture of things that don't really mix that well. At cranking speed particularly the atomisation isn't easy and droplets of fuel are common and require the only slightest provocation to fall out of suspension.

[Spokey]

Now that's a damn good question - honest answer is I don't know. same I suppose with Nikasil bores. I'll have a look into that one.

it's a big problem with diesel engines, the carbon in the oil can, if left and not changed enough, literally grind the bores smooth which polishes the honing marks away - you then get really bad oil burning and loads of smoke out the exhaust because the oil isn't sealing the rings.

Spokey

General consensus sugests that chrome plated bores tend to be in two strokes ( not any I've come across though ) and as these have the lubricating oil as part of the fuel mix so we assume that this is enough to lubricate the Parts required - and pistons tend to be turned so the grooves in the skirts will carry a certain amount of oil in them during operation ?
Apparently Nikasil is slightly porous so acts like sintering where the oil would stick in the porous parts ...

Spokey

[ogden]

General consensus sugests that chrome plated bores tend to be in two strokes ( not any I've come across though )

If Nikasil counts as chrome plating for the purpose of the discussion, the RGV has/had it.

[Stig]

I plug and play.

Key in, engine running, ride away.

[ogden]

I plug and play.

Key in, engine running, ride away.

Had any trouble with non-working bikes recently?

[Stig]

Had any trouble with non-working bikes recently?

SV. key in, engine start, ride away. (The first time of the day. After this it requires manual pushing along road, jumping, and gabbling and stomping of levers and pedals).

Dullsville. key in, engine start, ride away. (So long as it is above 10 degrees ambient temperature.)

YZF. key in, engine, start, ride away.

[STRAMASHER]

.......as long as it takes to shut the garage door. 5secs. Its all nice and easy 30 limits for me though.

[Spokey]

If Nikasil counts as chrome plating for the purpose of the discussion, the RGV has/had it.

2 stroke see ... :cool: even more of a need for good quality oil.

[SVGrandad]

General consensus sugests that chrome plated bores tend to be in two strokes ( not any I've come across though ) and as these have the lubricating oil as part of the fuel mix so we assume that this is enough to lubricate the Parts required - and pistons tend to be turned so the grooves in the skirts will carry a certain amount of oil in them during operation ?
Apparently Nikasil is slightly porous so acts like sintering where the oil would stick in the porous parts ...

Spokey
Thanks Spokey - I can imagine two strokes having chromed bores because with all the ports in them there is not a lot of metal left to hold it together and mid bore wear rates can be high. I seem to remember some four stroke bores being "hard chromed" for half their stroke, to avoid the wear step at the top of the bore. Your research much appreciated.

SVGrandad

[Kalessin]

Okay, so I wasn't too far off the mark then. Thanks for all the replies; I wish I'd posted a poll now!

[embee]

On the cold start enrichment theme, as an addition to the good descriptions already given, it's worth appreciating that quite a lot of heat is absorbed from the intake tract/inlet valve to evaporate fuel at normal running temperatures.

With cold starts and carbs, the whole of the intake port between carb and valve is wetted so you tend to need more enrichment than with port fuel injection where the fuel is targetted directly onto the back of the inlet valve and picks up heat sooner after the start. This is just one of the reasons why carbs are so bad for HC emissions.

In the interests of emissions of regulated pollutants (specifically HC and CO), and for combustion stability (cycle to cycle variability), port injection is usually timed to start just after the inlet valve closes to achieve maximum heat transfer and best combustibility of the mixture. Sometimes for acceleration response there might be an extra injection when the inlet is open to match air flow "gulp" when the throttle is snapped open.

Most modern car engines now use sequential injection, where each cylinder is timed in the same way. Early ECUs didn't have the processing capability and used "grouped" injection where two or more cylinders injectors used a common driver. This compromises the injection timing for at least one cylinder and makes the engine rougher running and worsens emissions.

An unavoidable consequence of this evaporation is that fuel vapour (as opposed to atomised liquid) occupies a big volume which would otherwise be air and thus reduces the potential power output of the engine (volumetric efficiency in air terms). Direct injection gasoline engines don't suffer this effect, with the fuel being injected directly into the cylinder rather than the port, and typically achieve several percentage points better operating volumetric efficiency. However they are not without other problems arising from not cooling and washing the backs of inlet valves, and problems with exposing injectors to combustion conditions.

Racing engines with port injection tended to have them way back at the bellmouth so fuel was held in the whole of the port and didn't pick up as much heat so didn't evaporate to the same extent in order to get better volumetric efficiency. Emissions weren't considered.

Note also that pump fuel volatility varies throughout the year, with typically 3 specs for summer/transition/winter. Using summer fuel in winter gives difficult starting due to lower volatility, likewise winter fuel in hot weather gives excessive enrichment and particularly hot fuel handling problems, vapour locking of fuel pumps etc. Volatility is measured as "Reid vapour pressure" or RVP, and there are strict limits in certain markets.

[Al_Sweetman]

Warm it up a bit. Start it, then put helmet and gloves on. Zip up any fleece pockets that may contain wallets :D


+1 - Also allows you to not look like a numpty if you put all the kit on and then try and workout:
a). Why the things not starting or
b). Realising you've left the disc lock on and have to try and fanny around removing it while fumbling without being able to see the lock and constantly headbutting the bars or fork stantions...

Not done either of those, of course!

:-)