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View Full Version : Warming up a Carb'd Bike



Glowerss
11th September 2012, 17:25
I've always heard (and read) that it was damaging to a carb'd bike to start it up cold and then ride it away. And that you should always let your bike warm up for a few minutes before riding off. I've always done this with my bikes.

However, when looking for something completely unrelated, I've come across some information in various bites around the web suggesting otherwise.

http://faq.ninja250.org/wiki/Warming_up_your_engine is a good example.

The logic for firing it up and then riding it GENTLY while it warms up seems sound to me.

Is there a sound answer on this, or is this one of those "Proper way to break in an engine" type arguements?

mossy1200
11th September 2012, 17:31
I prefer to wait untill the bike idles ok near normal idle with most of the choke off before setting off.

neels
11th September 2012, 17:36
I prefer to wait untill the bike idles ok near normal idle with most of the choke off before setting off.
Same, mainly because the choke on bike carbs isn't a proper choke, so it works for starting but not so good for running. Having said that, I only warm it up until the idle starts to come up and then head off.

However there is a school of thought that leaving an engine idling does more damage than warming it up faster with proper running.

MIXONE
11th September 2012, 17:44
I've always subscribed to the start it and ride gently for a few km school of thought.Of the 50+ bikes I have owned Only two required a rebuild (touch wood) and they were both triumphs.:rolleyes:

mossy1200
11th September 2012, 18:07
I've always subscribed to the start it and ride gently for a few km school of thought.Of the 50+ bikes I have owned Only two required a rebuild (touch wood) and they were both triumphs.:rolleyes:

Rather than warm the triumphs up you needed to add oil prior to each ride?

Fast Eddie
11th September 2012, 18:34
most owners/users manuals will tell you how to start/warm up engine.

the blade asks you to apply choke, start and run for 30 seconds and then rideaway. using low rpms and light loads until engine has reached operating temp.

old kwaka said wait until needle moves away from cold before setting off.

old suzuki asked that you please wait until oil had warmed up before thrashing it.. etc..

also depends entirely on the color of the carbs and power band

imdying
11th September 2012, 18:37
Just get on it and ride it as soon as it's tractable. The longer the choke is on, the longer a rich mixture is washing the cylinder bores. The lower the RPM, the slower the oil pump is turning, and that's the bit that lubricates the engine.

Teflon
11th September 2012, 19:55
I do. I start it using full/half choke (depending on bike), once it fires I turn the choke off and lightly blip the throttle until the bike idles fine.. I let it idle for a few mins before I take off short changing for a few k's.

I like to get a little bit of heat into the engine before placing it under load.

Katman
11th September 2012, 20:02
Look at it this way....

Every second you have your choke on is fouling your plugs.

Back in the day of leaded fuel the lead was the main component that cleaned the plugs back up again.

These days the only thing that cleans choke fouled plugs is running for a length of time at full operating temperature.

Therefore, the idea is to get the choke off as soon as possible even if it means holding the bike at a fast idle with the throttle (bear in mind that some bikes designed for the strict emission control regulations we have these days run like shit until fully warmed up).

Ride away on the bike as soon as it will idle adequately* without choke.


*Read 'adequately' - not 'perfectly'.

nzspokes
11th September 2012, 20:07
I have read that some motors suffer from a lack of lubrication to the cams/ rocker gear when left idling on the side stand as at idle there is a lack of oil pressure to ensure correct splash of oil squirters and it all runs down hill.

Could be BS but sounds true enough to me.

Flip
11th September 2012, 21:04
Its not really complicated. 70% of motor wear occurs on start up before the oil pressure goes up and the oil gets to all the important parts.

So start the motor and let it run quietly for a few seconds, then push the choke in and go for a ride, just don't screw the thing until the motor temp reaches its operating temp.

Glowerss
11th September 2012, 21:06
So the gist of things is, get it off choke as soon as reasonably possible, and as long as it will idle semi OK off of choke, it's good to ride.

Cheers for the info. I've been choking it overlong, as I've always heard/read that riding the bike before its warmed up can cause damage. Should make getting going in the morning much quicker :banana:

BMWST?
11th September 2012, 21:45
its fine having a warm motor but whats the point if your gearbox,tires,and rider are still not operating at he required temperatures/attitiudes

Fast Eddie
12th September 2012, 10:37
So the gist of things is, get it off choke as soon as reasonably possible, and as long as it will idle semi OK off of choke, it's good to ride.

Cheers for the info. I've been choking it overlong, as I've always heard/read that riding the bike before its warmed up can cause damage. Should make getting going in the morning much quicker :banana:

lol no.. the real jist of it would be read your owners/users manual. Every engine is different and manufacturers recommend different starting procedures. After all, they spend millions and years developing the engine - I'm sure they know something about it!! read the manual for your specific bike. How can you go wrong then?

Glowerss
12th September 2012, 11:23
lol no.. the real jist of it would be read your owners/users manual. Every engine is different and manufacturers recommend different starting procedures. After all, they spend millions and years developing the engine - I'm sure they know something about it!! read the manual for your specific bike. How can you go wrong then?

Pretty much unpossible unless you can read japanese :P I have the XJ600 manual, but the 400 manual cannot be found anywhere as the 400 was a japanese market only bike and was not widely exported at all. I've looked high and low for an owners/service manual and short of trying to google translate it, haven't had much success.

Not sure how much translates between the 400 and 600 in regards to this sort of thing.

Fast Eddie
12th September 2012, 13:24
buy a new bike with english manual

SMOKEU
12th September 2012, 14:38
If it's a 2 stroke race replica then you should warm it up for a few minutes before riding it. If it's a 4 stroke then ride it as soon as the engine starts "behaving" itself properly (as in, not wanting to stall with the choke off with light throttle application). I usually start my GSXR with half choke if it's cold outside, then turn the choke off after about 5-10 seconds, then it's ready to ride. Keep the revs below 1/2 way to the redline on a cold engine.