The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: flybot on December 23, 2012, 08:07:49 AM
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Im starting to test drive my '83 R65 restoration. Its in the 30-40 deg range here now and I was wondering what folks do with the choke before they drive off. Its kind of a two position choke. Full-on for a cold start, obviously. Do you warm it up for a min and then drive off with full choke and ween it down? Or do you warm it up till your on half choke? Just wondering what these motors like.
TIA
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Hello !
On my 82, I start full choke and let it run for a couple of seconds.
Then, I either lock the gas handle with the "cruiser" screw to have the engine at around 1200 ~ 1500 RPM and cut the choke all together or put the choke on the intermediate position to let the engine warm while I roll her out of the garage and close doors, put my helmet, gloves and the like.
I do not ride the bike with any choke left.
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Let the engine warm a bit prior to riding away. These Boxers develop BIG oil pressure numbers during frosty cold weather start-ups. Avoid blowing seals by letting that 20/50 oil get comfy.
As to the enrichener lever, each bike seems to have its own requirements. Listen to what your scooter tells you.
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I start on full, pushing the lever as far as it can go, after the engine starts, I usually am putting on my jacket gloves backpack, then reduce the lever to the half detent, depends on the day .
Opening the throttle before the engine is firing can cause hard starting .
Ride with the lever in the half detent about half mile or so (after my first stop light), then close the lever .
I leave for work at a little after 0500, so I don't have much traffic to deal with, so I go easy on the throttle until I get on the expressway after about two miles .
You'll have to find out what procedure works best for you through trial and error .
Cold start oil pressure can exceed 150 psi, that's probably why there are collapsed oil filters, as Monte has said a bit of warmup and a light hand on the throttle in the first couple of minutes .
Keeping your battery on a battery 'tender' is a good idea as well, especially during the cold weather .
I never thought much about battery tenders, but after using them for about two years, whenever my bikes are parked for the day in the garage, they are on a battery tender, I'm sold on them .
I've got them on four bikes and one four wheeler .
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Thanks for the responses guys. I wasnt aware of the super high cold oil pressure. Ill keep that in mind.
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Last years winter oil filter pictures below: Cold oil responsible, or cheap filter, or both?
I am very conscious of my rpm on all starts, regardless of temperatures, that includes the first 5 minutes of warm-up/riding, most especially when operating in the 40 degree Fahrenheit range. I will not let it rise above 2000 rpm's on the initial start up, less if I'm careful.
As far as how my bike seems to like to be choked, I would say it follows pretty closely with Bob's plan.
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There have been some suggestions, that aftermarket filters are more prone to collapse .
The hinged filter seems to resist the collapsing better than the one piece filter .
Not endorsing any brand of filter, you need to make that decision for yourself .
Euromoto Electrics has MANN filters for the airheads, as well as the oilhead bikes .
MANN is a filter supplier for BMW, I just replaced the filter on my BMW cage, got the filter from BMW, has MANN on it .
A few members here use them and so far, have not any collapsing issues with them .
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Like was said above, each bike has its own pecularities regarding starting. Not only that, but a given process may need to modified a little after you adjust the valves and/or carbs.
That being said, when I purchased my 1982 from the dealer, they said to start it on choke, go to half choke, and ride. Currently, my bike does not like any choke after it is started, so I just start and ride away (keeping it easy on the throttle until it is warmed up and ideling good). YMMV.
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I've had a collapsed filter so can endorse the caution about excessive revs when cold. 2 piece bendy filters are definitely stronger but just for the record there are documented accounts of both types collapsing including BMW filters. In fact the very first filters to collapse back in the 80's were genuine BMW parts as a result of BMW having changed their supplier. Besides going easy on the revs another part of my own solution is to use thinner 10W40 or 15W40 oil. I can get away with using this year round in a moderate climate and have no intention of ever using 20W50 at freezing or below when it's like treacle.
Starting techniques vary and you have to use what works with your bike. Below is a description of using the enricher by Snowbum and I find it an accurate guide. I never ride with the enricher on and don't even need the enricher to start above 10 or 12 Deg C which is consistent with "to use just enough to reliably start the bike" i.e. none if it doesn't need it. Don't expect the engine to idle when cold without holding it on the throttle and the fact that it won't idle is not necessarily an indication that the enricher should be on.
The proper use of the enricher is to use just enough to reliably
start the bike, then reduce it immediately, and use the throttle to
keep the engine running, and ride off, gently, soon. Except in the
coldest weather a warmup of over a minute or two is too long, just
keep the rpm reasonable for a few minutes. SOME bikes will definitely
require use of small amounts throttle during starting with the
enrichener, in order to get the engine running. Yes, I know this is
contrary to some published information.
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Starting techniques vary and you have to use what works with your bike. Below is a description of using the enricher by Snowbum and I find it an accurate guide. I never ride with the enricher on and don't even need the enricher to start above 10 or 12 Deg C which is consistent with "to use just enough to reliably start the bike" i.e. none if it doesn't need it. Don't expect the engine to idle when cold without holding it on the throttle and the fact that it won't idle is not necessarily an indication that the enricher should be on.
The proper use of the enricher is to use just enough to reliably
start the bike, then reduce it immediately, and use the throttle to
keep the engine running, and ride off, gently, soon. Except in the
coldest weather a warmup of over a minute or two is too long, just
keep the rpm reasonable for a few minutes. SOME bikes will definitely
require use of small amounts throttle during starting with the
enrichener, in order to get the engine running. Yes, I know this is
contrary to some published information.
Good info. Im still tweaking the carbs and my bike doesnt want to idle too well until fully warm (Ive only actually ridden it twice now). Ive got the throttle stops pretty much perfect. I need to go over the cable tension one more time. I pulled the plugs yesterday after putting about 6 miles on it. They looked perfect. I just wanted to make sure what its doing and what Im doing is "normal". From your responses, it sounds like it is. Im used to setting up dual carbs from my old 911 with dual 3 barrels, so that part isnt hard. Its just getting used to this type of engine and what it wants.
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A word of caution: Expect to re-do the mixture and idle speed if they were set before the engine was completely warmed up - which normally takes a good twenty miles or so. If they were set cold, then when the engine warms up the idle may hang around 2,000 RPM or higher.
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Im still tweaking the carbs and my bike doesnt want to idle too well until fully warm
That sounds as it should be. If it idled when cold then there would be something wrong with the settings. Certainly with the enricher off it shouldn't idle at the desired speed until fully warmed up and that can take a long ride especially in the winter.
The enricher was modified over the years with more holes in the disc which presumably was designed to make it more progressive and so it's effect seems to vary. Some say they can get a cold idle with use of the the enricher. Mine is an all or nothing effect which achieves an instant start when it's needed but the engine won't even run smoothly with it on never mind idle.
I watch other riders start their more modern bikes and leave it on a high idle while they put there kit on. That's not something you can do on a 79 airhead.
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Im still tweaking the carbs and my bike doesnt want to idle too well until fully warm
In my bike when carbs are properly set cold idle is way low and have to keep RPM's high with the throttle. At normal temperatures the idle stays at 1100. So don't adjust carbs for smooth cold operation.
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Good to know on the idle setting, because I think they are set too high right now. I wasnt aware it took so long to get it to "warm" temps. Also, i guess having to hold throttle for cold idle makes sense the way the carbs are designed. No hi-idle stops.
Great info here. Thanks guys. I was hoping to get her all tuned enough to drive to the DMV this week and get the tags for it, and then really ride it. But the temps have dropped to the low 30s (that 0's for you RoW folks). Too cold for me. But soon!