Stray Thought on Fuel Injection

pococj · #1 01-23-2005, 11:36 PM

Been kicking this "stray thought" around for awhile, brought on by the discussions here on carb vs. fi. One of the advantages touted for the fi is the ease of starting and the ability to ride off without messing with a choke. I've been wondering how many fi riders fire the bike up and ride off without allowing the engine to warm up a bit?

Granted, with modern oils and metallurgy engine warmup isn't as critical as it used to be. But owning an older Evo has made me aware of the necessity of proper warmup. They don't take kindly to driving off with a cold engine, and will let you know with leaking base gaskets, blown head askets, and leaking rocker boxes.

Of course the later Evo motors and the new Twinkie motors have different and better base gaskets/o-rings, and improved head and rocker box gaskets, so the no-warmup-leaks don't seem to happen.

I think with even the best oil, riding off before the engine is warmed a bit, increased wear will happen. It may not be much, but it will be there. But obviously this is my opinion, and I have no long-term studies to show anything, one way or another.

Y'all gotta remember I'm a cheap buzzard and squeeze the last bit of use outta my rides before they get an overhaul. And if you fi riders are wearing out your engines prematurely, what am I gonna do when it's time to move up to a Twinkie motored bike 10 or 20 years from now?

Pelonz · #2 01-23-2005, 11:58 PM

I have both EFI and Carb bikes........prefer EFI because of easy starting, altitude adjustment etc.....I always let her warm up a tad before riding off but not like I HAVE TO DO with the Carb bikes. I Take it easy for a few miles and make sure her throats warm before I make her sing

pilot1996 · #3 01-24-2005, 12:19 AM

Skip,

I usually let it idle until it's warm to the touch...I've often wondered if this was worth it or not...I say that because to my pee brain, it shouldn't matter...at least in theory, though I do it anyway.

Let me explain...the bike gets warm due to friction. Friction is tempered by oil. Oil is not present when you first crank 'er. Bike get's cranked, oil gets slung, some friction still is present, and bike gets warm. I get on bike, throw mama on the back, take off. Bike gets hot.

Now, if I cranked 'er, threw mama on the back, and took off, it'd get warm and then hot...oil is still getting slung from the moment I hit the starter. I've been told that the majority of the wear on engines is at the moment you crank 'er over.

I've always let all my engines warm before "going"...but I've never been able to explain why.

Granted, I'm a computer geek that likes to read and wished he had more time to do things with my hands...

Mac

jcc/tx · #4 01-24-2005, 12:39 AM

On the EVOs you would know by the valves rattling if it wasn't oiling. Would not "race" an engine until it warmed a bit, but I would think you could ride off normally after just a few seconds without undue damage. JMNSHO, of course!!

Would like to know what year the base gaskets were improved, if anyone remembers????

Pirate · #5 01-24-2005, 02:29 AM

I let mine warm a wee bit before riding off. Just a habit from long ago.

I was reading something yesterday that with the synthetic oils, its really not necessary, but I imagine I'll continue to do so. Can't hurt it to wait a minute

Tn.Heritage · #6 01-24-2005, 03:52 PM

I've heard the story's of what Skip say'ed about not riding off on the older Evo motor's because of blowed gasket's but now I don't think it matter's, so why do I let mine warm for 3 min. or so,give's me better piece of mind I guess.[sm=smiley20.gif] Hey Mac, your not getting a totally dry start on the engine like year's ago, the oil filter has a anti drain back valve to hold that liquid gold in the engine better, also the syn. oil's tend to cling to part's better than older conv. oil's did, so crank um up and move them out.[sm=pimp.gif]

breaknbad · #7 01-25-2005, 01:46 AM

I have heard the faster an engine warms up the better. In the summer i just start up and take it easy while it warms up. In colder weather i let it warm up for a couple of minutes but dont know why. I think it is habit from the carb motors used to run. I also like the oil to warm a bit.
My old auto mech teacher told me it is better on an engine to let it warm up going down the road as long as it doesnt stall and couse a hazard. He was talking about old carb cars but the same principal applies.
On a carb motor it is better to warm up faster becouse the longer you have the choke on the longer you will have the rich mixture of gasoline to find its way past the rings to the motor oil and contaminate it. It is never good to run a motor rich longer than needed becouse it can contaminate oil faster, wipe the oil off the cylender for faster ring wear, and foul plugs.

The more i think of it, im glad i have EFI.

Carbs do have some advantages though.
Ease of changing mixture if doing alot of engine mods at different times.

David

dm_gsxr · #8 01-25-2005, 07:11 PM

It always seem to work out that I warm the bike up for a minute or even more before leaving. I usually start the bike after opening the garage door but before putting on my helmet. After backing it out, lowering the garage door and putting on my gloves, the bike's probably reasonably warmed up. Works out about the same in the summer. Start, helmet, back out to the street, shut garage, put on gloves and go. So a minute or two of warmup before leaving usually occurs.

Carl

Wolf · #9 01-27-2005, 12:25 AM

I let my EFI bike warm up about 45 seconds then drive off. I don't get on the throttle hard at all until the oil is at full temp. which takes a full 20 miles in very mild winter weather here in Dixie. I have an oil temp. gauge on my Fatboy. I learned to let an engine warm up all the way when I used to SCCA road race. The consequences of not doing so just cost too much I found out through other people's mistakes.

gunns · #10 01-27-2005, 11:06 AM

One thing to keep in mind is that you will only help your motor by giving it time to warm. I have EFI and this is my first one, all others were carburated. I still let my bike warm for at least 3-5 minuets prior to taking off. That way I know she is reay to go and will handle almost anything I throw at her right off the line. I also use AMSOIL only. I have found nothing better yet. I use it in everything I drive i.e. bike, car, truck. I have it in my 84 chevy pickup with 220,000 miles and have not done anything but drive her. It dosen't win any races but does start and run everyday. You can get it at a distributor in bulk i.e. 1-5 gallon cans which will drop the price to lower then most top quality syn's.