Warming engines

[mistergixer]

Question for the techy bods really, should a 4 stroke engine be warmed up before use? I hear so many conflicting opinions on this and wonder which is correct.
One school of thought says the engine should be left to warm to ensure the oil has had a chance to circulate.
The other school says that the engine should be placed under a gentle load straight away, and the revs increased slowly.
The third school says hold it to the limiter in every gear, even when cold. I ignore this school.
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[strag]

Dunno what right really. I let mine tick over while I put lid and gloves on, then dont go daft till the temp rises. Suzuki book says make sure you don't load it until warm.
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[Barry_M2]

Its not good to thrash / race and engine when the engine and oil are still cold. You can ride off soon as you start it up, but dont race the engine until it has been given chance to warm up.

Also remember that the water will get upto temperature 'alot' quicker than the oil, so never use the temp guage as a guide. As a rule, I always give any of my engine's at least 4 or 5 miles from cold to allow the oil and the engine to get upto operating temp, until I give it any beans. Using a good quality oil also protects engines when cold.

Oil will circulate round the engine as soon as you start it up, you just need to allow it to get upto normal operating temp.

[Kickstart]

Hi

In some ways it is more important for a 4 stroke to be warmed up than a 2 stroke. However do not just sit there with it idling on choke as that is one of the worst things to do. Petrol washes the oil off the bores. Just ride off and take it easy for a while.

[riichy]

i leve mine about 1min then ride of and take it easy for abit. then the morning fun starts
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[craigs23]

I always warm all my bikes before setting off, my start up procedure is quite religious (and I get a few 'is your bike okay' looks).

I switch the ignition on and always buzz the starter with the kill switch off until the oil light goes out.

Then I start the bike and set the choke so it idles at around 2,500rpm whilst I get my gear on.

Always wait until the bike freely idles at about 1200rpm before setting off (reaches a steady 1400 when fully warm).

I keep below 7,000rpm until the temp. guage hits 70oC.

Then stay below 10,000 until it reaches 80oC.

Only after then it's playtime and full use of power.

I also warm down the bike after a decent thrash (a cruise through town at sub 8000 is usually best for this).

[KevTM]

i never need to use the choke to start mine, just leave it ticking over until i put my helmet etc on and the tmep guage reads over 24 degrees roughly (about 1-2 mins) then take it easy until it's at normal temp.. around 75 degrees usually.

[Robby]

Get on and ride straight off.

The oil doesn't get warmed sitting there ticking over, the coolant will though.
To get heat into the oil the engine needs to be under some load. Load = heat, and also forces the piston rings against the cylinder wall. This gives a good seal, and prevents blow-by. Blow-by is bad for oil. Also at tickover the oil pressure is pretty low.

To put it simply, your bike is made from very tough metals, with very good quality muligrade oils. Multigrade oils are designed to work in a wide range of temperatures.

And Craigs23, if you do that to all of your bikes I'm never buying a bike off of you.

[craigs23]

And why is that?

[veeeffarr]

[craigs23]

Duly noted, when warming the bike's idling at 2,500-3 whilst I'm getting geared up though, does this incur the same problem? I'm only going by what I've been told:

https://i3.photobucket.com/albums/y51/whers84/hrcwarmup.jpg

The throttle is blipped before pulling away (sitting on the bike putting gloves on for example)

[Adam_P]

Race engines are turned over in the same Craigs23 does, mainly to get the oil pressure up before strking it up.

Warming it up is a case of giving it varying revs. I usually start mine up, give it a few second to let the oil get to where it is meant to be then vary the revs, but not too high, until the water temp gauge has stopped blinking at me. I know then that its pretty much where it needs to be and I can ride off.
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[Yorkshire Puddin']

I prefer to get a couple of bars of heat before doing anything i.e. start bike, smoke fag whilst putting kit on...this is from stone cold.
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[Dan 4RR]

Normally about 5 mins before I set off, I start up the bike, then go back inside get changed into my gear put lid on etc. Usually by that time I think it's alright to ride off. But for the first mile or so I keep to around 30mph until I let it rip.

[priller]

I just start the bike & ride off, keeping the revs low until its warm.

[Kickstart]

[Robby]

Its the business of turning it lots on the starter motor first that worries me. The oil pump is driven by the crank, and is pumping oil when the crank is spinning. Just starting the bike and letting it tick over for a couple of seconds is enough to have the oil moving. Your cams may be spinning with just the residual oil sitting on them for a second, thats not going to kill them.

Turning it little bits on the starter motor is going to cause unecessesary wear to the starter motor and starter clutch, also it would probably cause the crank and cams to have to do more revolutions with low/no oil pressure.

On a race bike that idles at 8k rpm it would be a different matter, I could understand spinning that on the starter motor or remote starter with the ignition turned off to get the oil distributed around the engine and some pressure up before starting, but not on a road bike.

[Kickstart]

[knockout_bar]

When my KE175 (2 stroke) was working. You used to have to start it from cold with the choke fully open for about 3 mins. The bike would then settle down to a steady tickover and would ride fine with no hitches.

Try starting the bike with the choke open for only about 30 seconds and if you tried to ride off, the bike would really hesitate, refuse to rev up from tickover and the engine would be really jumpy.

I started it the latter way one day and when I took the top end apart, the piston was scored badly and the top ring was blown.

When I started it using the first method, the piston and rings were fine (after a quick top-end rebuild).
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[Kickstart]

Hi

2 stroke has a very different lubrication system. For a start oil is lubing the bore both above and below the piston and the bearings are designed to take the abuse of having loads of petrol on them (mixed with oil).

With a 4 stroke some of the fuel will get past the rings, will dilute the oil and will then get pumped at high pressure to "protect" some bearings, such as the big ends and the cams. Petrol is a useless lubricant.

All the best

Keith
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[knockout_bar]

So was I warming my 175 up the right way when I left it on the choke for 3 mins?
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125 trail bike, custom bars, handguards etc. - ?500.

"egg flied lice" - R6jonny (inspired by McGee)

[Kickstart]

Hi

Personally I would start it and ride it off asap. The RS125 (well, my one) will start and run immediatly without choke. It will not idle but will pull fine at the low throttle levels I am going to use until it is up to temperature.

All the best

Keith
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[Kram]

i can't sit around all day waiting for my bike to warm up... when you have to bump start it.

i haven't used my choke for about 2 months. it's to warm to do it,

i tend to leave it for a miute then ride gently till i'm out a few mile
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[craigs23]

Well, I'll change my starting procedure if it's really causing that much damage - though I have no side effects at all from starting like this, despite using a similar method for all the bikes that I've owned through 6 years of riding. No perculiar noises, no performance deficit, no oil burning and from servincing, no abnormal wear rates on the engine's internals (although I haven't looked at the piston bores since my 400/4 days).

What kind of symptons would be noticeable with prolonged starting in this fashion? Am I really doing any damage to my bike?

Edit: bare in mind that I don't follow this procedure everytime I start the bike - only after it hasn't been used overnight or similar. After parking up to a rideout/going into town/riding to work, no choke is ever needed on my bike - starts on the button first time, everytime.

[TOM M]

I normally pull the bike out the garage and turn it on and let it idle for 1-2 mins whilst i put me lid, jacket and gloves on.
Dont tend to ever leave it much longer. Then when i set off, i keep at fairly low revs for a few miles to get her up to temp.
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