hello all, im new to this forum and would like to tell all a secret for engine longevity.........WARM UP THE ENGINE !!!! before you put it in gear . doing this will let the metal componets such as pistons,crank, rods,and cases to expand and reach proper clearances for the shelled bearings of the crank, balence shaft,and rods. the pistons need to expand in their cylinder bores .the cases also need to warm up to let all the internals ,head and valvetrain to stablize . i wait until the temp gauge needle moves off its post, and is right below the screw on the gauge face.this is about 7 minutes.if this is not done and you start cold, you can expect life of the engine reduced 40% so its worth the extra time and have a engine that is happy and willing to do what you want it to, and maintain its longevity.
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Really? C'mon man.... Idling at 1200 rpm or so on a cold engine is ok, but anything above that results in a 40% engine life reduction? really? Where did the precise measurement of 40% for anything above idle come from? Whether I'm at 2000 rpm at 30 mph (15% engine load) or doing a smokey burnout while flying out of the garage (100% engine load), 40% life expectancy loss eh? ugh....:bang head: You ever have fouled plugs from letting your cold engine idle for too long? You ever experience oil dilution where fuel gets past the rings and into the crankcase because of fuel condensing on the cold cylinder walls after it was flash heated by the remnants of the previous combustion? Letting your engine idle cold is not great for it either. Both of these occur readily and easily if you let your bike idle for too long or never bring the engine up to temp. Getting your engine up to temp as fast as possible with the least amount of load on the engine is best for it. Idling does not do this. Ever notice how not one single engine manufacturer recommends letting the engine come up to temp at idle before driving or using it? On particularly cold days, it actually does more harm than good, the engine never actually warms up. The condensing fuel wipes the oil from the cylinder walls and reduces lubrication causing cylinder and ring wear. Not one single manufacturer recommends this because it is not necessary and can cause premature failure all in itself. Most every manufacturer recommends immediate product usage directly after starting, however most do not recommend going to WOT.
My point is that there is no need to let an engine warm up before "putting it in gear". Absolutely no reason. You're probably asking yourself how I could know this for fact and sarcastically asking if I'm some kind of engine development expert......well, turns out, yes, I am. I've been an engineer with the world's largest engine manufacturer in the world for the past 8 years. I'm not trying to inflate my ego, just stating that I have some credentials in this area and have many years of actual thermodynamic testing experience using huge arrays of data acquisition equipment on and inside engines.
It is OK to fire up your bike on a freezing cold morning and head out of the garage after 5-10 seconds......as long as you take it easy and keep the throttle position and rpms to a minimum.
The only reason to let your bike idle after starting cold is to build up oil pressure and get everything properly lubricated. That takes about 5-10 seconds. Unfortunately, small amounts of damage occur with every cold start during the time that it takes oil pressure to build and for it to slosh onto parts that are not pressure fed, part of why every engine will wear out over time.
You must ALWAYS warm up the engine before you put full load on it. Failure to do so can potentially cause engine harm due to improper tolerances of crank and cam journal bearings as well as the rod bearings. The pistons are not affected so much because of the flex of the rings themselves. In addition to clearances not in spec due to thermal expansion, you need to consider the viscosity of the oil. I have witnessed thrust washers and crank journals exceed 500*C on a cold start then instant WOT scenario. 9 repetitions of this roasted the #3 bearing. It was due to the lack of lubrication because the oil could not flow adequately through the tight clearance to feed the bearing.
I think your theory is justified, but I believe that your expected engine life reduction amount and your warm up time/method are both extreme. Dont worry about taking off after a cold start, just be nice to her till she gets up to temp. Then beat her hard!!! hahaha!! :rocket bike: