One down, one to go (I hope!)

[boxer54]

happy days i spent riding the south coast of UK on my days off.
Smug atop 'Rusty James', my 1986 BMW r80 mono. I say smug because as if you read my first post, I managed to discover the gremlin behind my intermittent starting problem (with the as yet gracious help of the forum) and learning a lot along the way. As seems to be the way with forum life, one trawls and searches for that nugget of wisdom to apply to one's own mishap and hours, days, weeks pass with a knowledge learnt that you hope you'll able to apply sometime....

Some more boxer algebra for ye...

I recently had the timing checked and carbs balanced, by my friendly, refuted mechanic. The bike was running sweet, staring on the button, quick off the choke and smooth into the idle and with a recent shaft and engine oil change, it felt like she was smiling too. We were happy all summer long, but like so many summer romances, when the weather turns, so too does the happiness!!!

My suspicion started about a month ago. I had not taken her out for 5 days or so and was considering calling it a day for the winter, removing the battery etc; albeit reluctantly. I was dragging my feet and itched for more hours in her saddle!!

I do not ride daily. About a month ago on a 50 or so mile trip I noticed she was 'hesitant'. I am still 'learning' the bike but this I would describe as 'driving with the handbrake on'. I know that sounds silly to bike riders, but hopefully those car drivers among ye know what I mean. She felt 'choked', like it wasn't getting the fuel it needed. And it was at low revs. And occasional misfire at low revs. Once I got the revs up she seemed ok, but I wasn't happy riding like that (see my first post LOL!!) and something was obviously wrong.

All this said, it felt like she would get me home, I had confidence on the machinery if that makes sense, and she got me home. Meanwhile back at the studio.....
I checked the spark plugs (it has four) and all a little blackened, the right top being the worst (black/ sticky/ oily). I changed all 4 to no avail and booked it in for a check up/ timing check/ carb balance but on the ride there....no problems. Sweet running, warming up sweetly, no misfires. I left her with mechanic, sync'd, collected, all good, running fine, until....last weekend. Teaching a friend to ride in a car park we topped up with fuel on the way. First day she was fine, second day was the return of the stumble, the hesitantcy, the misfire and the general poor acceleration at the low end....

I mentioned topping up fuel as I wonder if some dirt in tank was stirred up at this point.
I intend to check carb diaphrams and clean fuel pipes.

Any more ideas most welcome
PS Apologies for the long post!!

[SteveD]

UK huh! Any water in the float bowls?
How old are the HT cables and plug caps?

[Ken in Oklahoma]

PS Apologies for the long post!!

Omigod! A serious post about a real beemer problem being presented to a bunch of know it alls. This is what we live for!

Well, OK, one of the things we live for.

Ken

[Rev Light]

I would be checking my float bowls first, unless there is something else you have recently disturbed. When I have found water in mine, I would get a misfire and bogging down at higher RPMs/speeds, which is not your symptom. Dirt/debris is another matter, however.

You mention the tank. Have you ever flushed it out? I empty mine every year or two to get rid of any crap/water that has found its way in. People far cleverer than me will chime in about whether or not to run extra fuel filters, assuming that the one in the tank is intact.

Rev Light

[PITAPan]

happy days i spent riding the south coast of UK on my days off.
Smug atop 'Rusty James', my 1986 BMW r80 mono. I say smug because as if you read my first post, I managed to discover the gremlin behind my intermittent starting problem (with the as yet gracious help of the forum) and learning a lot along the way. As seems to be the way with forum life, one trawls and searches for that nugget of wisdom to apply to one's own mishap and hours, days, weeks pass with a knowledge learnt that you hope you'll able to apply sometime....

Some more boxer algebra for ye...

I recently had the timing checked and carbs balanced, by my friendly, refuted mechanic. The bike was running sweet, staring on the button, quick off the choke and smooth into the idle and with a recent shaft and engine oil change, it felt like she was smiling too. We were happy all summer long, but like so many summer romances, when the weather turns, so too does the happiness!!!

My suspicion started about a month ago. I had not taken her out for 5 days or so and was considering calling it a day for the winter, removing the battery etc; albeit reluctantly. I was dragging my feet and itched for more hours in her saddle!!

I do not ride daily. About a month ago on a 50 or so mile trip I noticed she was 'hesitant'. I am still 'learning' the bike but this I would describe as 'driving with the handbrake on'. I know that sounds silly to bike riders, but hopefully those car drivers among ye know what I mean. She felt 'choked', like it wasn't getting the fuel it needed. And it was at low revs. And occasional misfire at low revs. Once I got the revs up she seemed ok, but I wasn't happy riding like that (see my first post LOL!!) and something was obviously wrong.

All this said, it felt like she would get me home, I had confidence on the machinery if that makes sense, and she got me home. Meanwhile back at the studio.....
I checked the spark plugs (it has four) and all a little blackened, the right top being the worst (black/ sticky/ oily). I changed all 4 to no avail and booked it in for a check up/ timing check/ carb balance but on the ride there....no problems. Sweet running, warming up sweetly, no misfires. I left her with mechanic, sync'd, collected, all good, running fine, until....last weekend. Teaching a friend to ride in a car park we topped up with fuel on the way. First day she was fine, second day was the return of the stumble, the hesitantcy, the misfire and the general poor acceleration at the low end....

I mentioned topping up fuel as I wonder if some dirt in tank was stirred up at this point.
I intend to check carb diaphrams and clean fuel pipes.

Any more ideas most welcome
PS Apologies for the long post!!

Ideas?

Lose the "her". It's a machine, not a "her". The way you deal with a machine is nothing like the way you deal with a "her" or a "she". Precisely logical and analytical thinking will not get you far with a "her" but it's everything when dealing with a machine. Confuse the two, even slightly, and you will get burned coming and going. "her" and "she" doesn't like being thought about like a machine either. if you want a "her" or a "she", go get one. They're cuddly and some of them can cook well too. But they can also create incredibly expensive little replicas of you that want to borrow your machines after you have put enough money into them over the years. So watch it.

You think in the words you speak (or here, write). Your thinking about the machine is not strong----yet. The bike lacks gender so get rid of that from your thinking.

Next, lose the mechanic. If the guy will talk to you about what's going on that's good. You'll pick up some knowledge---or at least what they know. But it can get in the way of actually thinking about your problem. You are paying them to make your problem into their problem. This will not lead you down the path of solving your own problems. Nothing wrong with that---it's the only way some people fly and they are quite happy with the arrangement. They ensure they can always get to the mechanic one way or another when they need to and that's that. But if you want to be self sufficient, either for economy, reliability/robustness, or both, then you have to make the mental commitment to solving your own problems. I don't make light of this. I would venture that most people are not in the habit of thinking much about anything. Their lives do not demand the effort and frankly, if you make yourself into the sort that notices things and thinks about them, you are going to notice and think about some rather disturbing stuff. Aweful lot of bullshit in the world and the typical way to cope is to turn your brain off. The people putting out all that bullshit depend on this. I've copied the hype off a box of fried chicken and am thinking about putting it on my blog---it's pretty amazing stuff and if you think about it, pretty sick and destructive. But they want you to buy that chicken, they are counting on your not thinking about much of anything and going for whatever crap they print on the box.

Next: Confidence. Yes, you can do it. And you can do it really well too. And you can get to doing it very well a lot quicker than you might imagine. This requires some raw faith. You don't know the extent of what you don't know and that vast gray area can be intimidating. The mind draws dragons into the blank areas of the chart. But knowledge is easy to acquire. No laborious thinking required. The Bing manual is unusual because it actually tells you how the carbs work. Read it and now you know that. Learning your tuneups is a great place to start because they need done often. Diagnosis of a tuning problem is more tricky and here your abilities at analytical thought come into play. But you have committed to using your mind that way so you forge ahead. More effort in the beginning but after a while you become accustomed to it, you avoid the effort less and get bothered by the bullshit on the side of the fried chicken box more.

Observation is critical of course. I have your words in front of me rather than your bike. Not ideal. So I observe your words. You say "'(like)...driving with the handbrake on'. Ya know, the first thing I would check is the brakes and wheels. Get each wheel off the ground and spin it by hand. Some sort of drag here does not fit with the other things you describe but it does fit with one thing you 'feel', and it's a very quick check.

You say it runs poorly at low throttle but does better when you open the throttle more. Well, as the motor runs faster it uses more fuel. If the main fuel supply is choked up, it will run worse as it needs more fuel, not better. In any event it is running too lean with too little fuel. This will show on the plugs but you have to do proper plug chops. looking at them in the driveway won't give the correct picture. google 'Plug Chops'. If you drain the gas out the petcocks into a gas can with a scrap of fuel line, you can examine the screens on the top of the petcocks in the tank. I use a snake light (Streamlight Stylus Reach.). A penlight will do. It takes a huge amount of crud to hurt fuel flow at the screens and the crud piles up at the base of the screens. On a full tank you are running fuel through the full height of the screen---as in the clean upper portion. The bike will run fine on one petcock. If you suddenly need to turn both on to keep it going (with a full tank) suspect a feed problem a the tank. Your fuel pressure at the screens also changes with the height of the fuel in the tank so if your feed decreases as the tank gets low, suspect a problem. The last word is always the actual flow and you can measure this simply. Data on Snowbums site for ml/time. If you run filters (wise) you would check those too---or just change them if they are getting yellow.

If you have a problem in the carb circuits, like in the low throttle circuits, then you get what you describe. However what are the odds a bit of crap clogged the idle jet on both carbs at the same time? Water will be in both carbs and you'll see it instantly looking in the carb bowls. But other wise one carb will be the one screwing up. You get a lot of vibration from the power imbalance. Ditto a diaphragm problem. It is possible I suppose to get a tiny pinhole in a diaphragm. The needle won't lift on that side at low rpm and the mix will go lean and weak. Again, look for the vibration in the now unbalanced engine. You might have an air leak driving the mix lean or the choke(s) on driving it rich. There are quick and simple checks for both conditions. You can get into some further observations to see what the mixture is doing. Plug chops are good for the upper ranges. A lean condition will also run too hot. So polish out a stripe down each header and watch for how much and fast the blue comes back on each side. You can also use a thermometer (like an IR) to check head temps.

It is worthwhile, as a beginner, to untune your carbs and ride around---just to see what it feels like when a given carb circuit is off on one or both sides. Now you know what feels like what---ahead of time.

Loss of power but not smoothness means something is effecting both sides equally. Drag at the wheels, a slipping clutch---something like that. Don't forget seasonal changes in gas formula screwing with your tuning twice a year---not to mention your gas getting old. It's only good for a month without stabilizer.

The electronic ignition is a set it and forget it. For a long looooong time. The mechanic advance might get sticky and will announce itself, typically a hanging high idle, but the timing simply won't change. You check the timing with a strobe light and the money and time involved, including the time to learn the drill, is so much less that what you paid the mechanic it's silly. You don't need a timing check unless someone screwed it up in the first place---and if the mechanic finds it off they should fix it free---they screwed it up. This is not true with points. You do not have points.

Sooty plugs in the driveway are to be expected. Until they hit self cleaning temp (take it out and flog it already!) they are going to look crummy. But upper plugs shouldn't look oily or wet. That is either an oil problem (couple of ways) or a vastly too rich condition---choke stuck on or something---or the wrong plugs. In some cases an ignition problem which is very worth checking.

If a plug isn't sparking consistently then the cylinder isn't firing---unburned gas and oil build up on the plug (hosing it further) and there is a loss of power. Can strike one side or both at once depending on where the problem is. The dual plug setup is more robust and depending on how it is wired a problem may be more or less obvious. It should be cross wired so each coil feeds both sides---most robust but also obscures some problems more. If the lower plugs are the wrong ones and are crudded to high heaven, you have a single plug setup and it should be assessed as such (and correct the lower plugs). Weak sparks are obvious---observe the sparks with a new plug on the wire, firmly lashed to the head with a bungie. Limp and yellow=bad, blue white=good. This indicates the condition of the coils. Missing sparks are very hard to spot unless there is a massive problem. Just check the resistance of the wires and the plugs (separately) and make sure the high tension connections are clean. Also a film of silicone grease in all the boots---keeps out moisture that can short the sparks---this can be a seasonal thing in some climates. I recently had some severe corrosion in a boot at the coil. The coil socket was packed with white and green baddness. Just one out of the 4---others impeccable. WTF? No symptoms from it but I cleaned it up anyway and will keep an eye on it. Commercial wires go bad. My home made ones don't---but have some other implications that don't recommend them for the beginner. Sometimes commercial wires can be repaired---ones with screw on caps can have the caps removed, the wire trimmed 1/4" and the cap screwed back on to the fresh cut end.

Spark issues are typically either all the time, only on the high end (from greater cylinder pressure), or only when things are hot (weak coils). If it's really bad, you notice the misfires---but those can be more obvious to feel at lower rpms even if you have them throughout the range.

Never assume there is a problem. You can have several. You might have a carb issue that goes un-noticed for a long time until a spark issue crops up and now you don't have the sparks to cope with the bad mix and it starts running poorly. Or a weak spark that doesn't affect much until you also get a bad mix or are running high loads on a tour in the mountains two up with the "her" you found. Evaluate everything.


Short trips and low speed work is good for crudding things up. Use SeaFom in the gas to keep the cars clean and stabilize the gas if you aren't burning a tank every 2 weeks. Always buy your gas at the same station when possible and never when the gas is being delivered. You are reducing variables. Take it out for a real ride before calling foul.










IMNSHO; don't teach people to ride on your bike, teach them on their bike. If they don't have a bike they don't need to learn how to ride, right?. If they must learn before getting a bike, they can use one the MSF provides for the purpose.

[She'llbe]

Wow , I think that's the longest writing in the history of this forum. I gotta give Melville credit for his long thread though.

[melville]

Wow , I think that's the longest writing in the history of this forum. I gotta give Melville credit for his long thread though.

PITApan (Plaka) follows his own obsessions.

[PITAPan]

This forum keeps getting smaller. Plonk.

[Duane Ausherman]

I once encouraged everyone to do the work on their bike. I was wrong. Just watch some people pick up a tool. They are going to hurt themselves, or someone else with that tool. Some people just can't do mechanical work.

The roommate that started my education in BMW could talk someone through just about any procedure. He knew what he was talking about. Don't ever let him try to do the job himself. He will mess up a simple valve adjustment and maybe hurt himself, or the bike, break the too, or all four.

[PITAPan]

I once encouraged everyone to do the work on their bike. I was wrong. Just watch some people pick up a tool. They are going to hurt themselves, or someone else with that tool. Some people just can't do mechanical work.

The roommate that started my education in BMW could talk someone through just about any procedure. He knew what he was talking about. Don't ever let him try to do the job himself. He will mess up a simple valve adjustment and maybe hurt himself, or the bike, break the too, or all four.

I still believe anyone can do it (if they have hands, met a few who didn't). But one needs to be honest with oneself about the state of their abilities and be committed to developing the needed skills. It's an attitude thing --and there is a piece of knowing what is good work and what isn't.

I still recommend certain books to people that fill in all the basic info--including how to use the tools. The wrong attitude will assume that is simple. The correct one with understand there is far more to know than is immediately apparent.

There are also exercises one can do to develop skill and 'feel'. Some develop feel for torques, others for max. permissible loads or order of assembly. Some are simple---the old torque-wrench-in-the-vice exercise, others more complex---the find-some-thing-else-to-screw-with-and-break-that routine. Along with skill such exercises develop confidence at doing the work correctly.

I have learned some very tricky things that I wouldn't have anticipated. Like color matching a certain kind of paint. That took about 3 months of intense (often round the clock) effort mixing thousands of little dishes of paint. In the end I could see things in the color I wouldn't have imagined before. A lot of developing visual sensitivity. I began with no talent and still don't have any. Total slog from beginning to end. But if I can do that (never mind my equally inept fellow students), anybody can learn anything else. Some things take years of laying groundwork. I can tear through a new book on neurobiology but I have 40+ years of background. Try to master some new bit of mathematics (ie, any of it) and I struggle. I recently got tired of not understanding the function of a component on the airhead wiring diagram. I recognized that I had been avoiding it for years (likely out of fear) and there was no reason I couldn't have an understanding. It took about 2 hours of fairly concentrated effort. My attitude had been blocking my understanding. Good reminder, albeit a bit shameful that it took so long to figure out.

Balancing my belief that anyone can do it, and well, is the knowledge that many won't have the attitude and wisdom to pull it off (many that would like to that is).


Side story: I worked with this guy once who was a documentation specialist. His job was to write the manuals for the machine (mine was to design it). He was an honest 6' 3", perfect physique and classically handsome. I mean, he could have modeled any day. But he didn't know one end of a screwdriver from the other. He had to write up service procedures ($100,000 lab serum analyzer, Ciba-Corning Diagnostics) but he couldn't do the service!. He was taking chunks of the machine home at night to work at his kitchen table and painstakingly figure out how to get the doors and hatches open. He complained bitterly to me one day, "People see a big good looking guy and they think 'handy'. But I've never been handy!".