To warm up or not to warm up....

A question that has been thrown about a lot. Is it best to warm a modern bikes (2004) engine up before you ride it or not? My bike is carbed and is a little spluttery until the carbs are warmed up. Someone told me last week that you can damage an engine by warming it up too long and that I should just turn it on and ride it carefully at first. I always need a bit of choke when starting from cold but not for very long (30secs to 1 min) But I never let it race. Someone also told me you can damage the engine by putting a load on it when cold. Who is right? I usually warmup my bike for about 2 - 3 minutes before hopping on.

Cheers,

Dan

[Kylie]

I've been told that you should not start the engine until sat on the bike, starting it on the side stand means uneven oil. As a result I get on, start, then roll away and take it handy for first few minutes.

Originally Posted by Kylie

I've been told that you should not start the engine until sat on the bike, starting it on the side stand means uneven oil.

For an IL4 it might be an issue, not for the SV though.

As far as warming up goes, it's certainly much debated. When an engine is new, it shouldn't be warmed up as part of the "running in" activity requires that the the cylinder bores are slightly worn to allow the piston to "bed in" and create an almost perfect seal. Should this not happen then the cylinder bores will glaze (often achieved by excess "warming" of the engine prior to riding away, or indeed, not using enough revs and/or too much of a constant throttle), which will mean that oil slowly escapes in to the cylinder (because there's not a perfect seal) and is burnt with the fuel, meaning less power and more oil consumption.

Once the engine's fully run in (maybe 1500-2000 miles in reality) then, providing you knock the choke off after a few seconds, warming up is fine and can be reasonably benificial to an engine as pulling away on a totally cold engine causes stress and wear.

A good rule of thumb is to start your bike (knock off the choke ASAP), pull on all your gear, and then ride away slowly, short-shifting for the first mile or two.


.

I doubt the angle of the side stand will make any difference.

I start mine whilst I am gettng my gloves on and ride off once the temperature read out appears.

As to how long you should go before using all the revs....that is another matter.

My car doesn't give me full revs for around 5 miles at least.

The bike doesn't have a rev limiter that adjusts with engine temperature... It is also a smaller engine so I assume it warms up quicker?

I don't treat mine any differently when it's cold to when it's warm. Only bike I ever have done is my old Aprilia.... and it still blew up lol.

im a start and ride kinda guy, taking it easy for a few mins,

but thats more to warm the tyres up more than anything, i try not to go above 6k when the auto choke is on.

its such a minor thing, that i doubt it will make a difference in the grand scheme of things

The choke full on me ole Kawasaki would run the cold engine to 4500prm with the first press of the button.

Bad news all round that.

[fizzwheel]

The SV I warm it up on the choke whilst putting my gloves and lid on as I dont like riding with the choke on.

The GSXR I just tend to start it and ride it. I dont ride it hard till its warmed right up though.

[embee]

Start it, let it "settle" for a little while so that the worst of the cold start enrichment can be removed (close choke if carbs, FI will do it on its own), maybe 30sec or so, then ride off gently, avoid high revs and wide throttle opening until it's fully warm. Trust me .

Cold cylinder surfaces promote condensation and contamination of the oil film on the bores, and extra fuel from cold starting enrichment gets absorbed into the oil film too. This all leads to undesirable wear. The best way to warm up quickly without causing undue distress is to drive/ride the car/bike gently.

Don't blip the throttle straight after a cold start, that is the best way to generate plug fouling . If you're using a colder grade plug than standard for any reason (ignition advanced perhaps), then it's all the more important. If you do have cold plugs or get any plug fouling problems, the best way round it is to do the normal start, let it settle for the usual time (you don't usually get fouled plugs if left alone during this phase) then gradually and gently ease the speed up to, say, 3000rpm and hold it steady (choke off) for 30sec or so. This will get the plugs hot enough to self clean and can virtually guarantee no fouling. Again, don't blip the throttle and don't put sudden high load on it (big throttle opening) until it's warmed up.

Whatever you personal views on iridium plugs, they do generally let you get the choke off sooner, and/or improve cold driveability and reduce the likelihood of plug fouling.

[Biker Biggles]

Embee and Warren are right.The engine warms up quicker if you ride off,but a balance has to be struck by not overstressing it when cold.The least wear occurs when you warm it by riding gently.
And other bits need to warm up too,so tyres don't get mullered by hard riding from cold and you are not tempted to go for it in the first mile or so and overwhelm slippy rubber.Even the shocks work better at running temperature.