How to get an R1150 to fire off like a K75?

[JHGilbert]

The K75RT would fire off fast even on 26 degree mornings with only one or two cranks. Never a problem.

The R1150RT turns over slower, cranks longer and finally fires off like it has a bit of emphysema, even with the cold start levered to the fastest idle position. One BMW mechanic told me that it will never start like the K75, but keep cranking it and it will start. It also has the notorious surge between 3 & 4K rpm. It runs great once slightly warm.

I'm planning on wrenching it this next weekend. This is what has been done:

Pretty new BMW Gel Battery (less than a year, I think; PO-always kept it on charger)
New Autolite platinum sparkplugs

What will be done:

New cam chain tensioner
Adjust valves
Sync throttle bodies

Since this is a daily driver, I want to make sure it starts reliably by the time Fall/Winter get here. Any thing else I should look at while I'm in the bowels of the beast?

[MotorradMike]

Hi JH:

Seems every engine has its quirks. As long as it always starts, and runs well, who cares if it's a bit cold blooded? A good friend of mine has a Norton 850 which he almost always manages to get to start "first kick" every season. Why?
Other things are more important.

My 2 cents.

[35634]

Synthetic oil might help, it flows easier when cold. Made the difference between
start and no start with my old TR Spitfire. Pull the clutch in so you're not turning
over the gears. Quick starts are just emotionally gratifying!

[ljjohns]

;)Ignore Joel's complaints: he's merely suffering from seller's remorse because I ride his K75 by his house to work every day and then park it close to his office at the University.

It just reminds him of the price one pays when one goes from K's to R's:laugh

Larry Johnson
K1200LTC
K75RT:dance
K1100LT (sold)

[JHGilbert]

As long as it always starts, and runs well, who cares if it's a bit cold blooded?

I care. In winter it will crank slower and have fewer reserve CCAs. It will sit out until long after dark when I finish teaching and then it'll get me home. That's it's job. Having wrenched all my life, and the last engine I had that started this slow had a 4-barrel carburetor and we always tuned them well before winter set in.

;)Ignore Joel's complaints: he's merely suffering from seller's remorse because I ride his K75 by his house to work every day and then park it close to his office at the University.

It just reminds him of the price one pays when one goes from K's to R's:laugh

Seller's remorse....yep. At least until I go over a set of railroad tracks (or any other bump). Or take the 120 mile route to go to a town 30 miles away for coffee. Or drive into the rain and raise the windscreen to keep dry. And then there is that growl when you open 'er up....:burnout

[ragtoplvr]

If your temperatures are mostly below 80F in the winter, Rotella 5W40 is a good starting oil. Really transforms cold weather operation. If you get stuck in traffic a lot and hit 6 or 7 bars this might not be a good choice, but for me it works great.

Rod

[rinty]

My 1150 RS used to light off within a crank turn or two, even when it was cold out, so you may just need to do some tuning.

I recall one morning at the Stanley Stomp when it was 27 above, bikes were covered with frost, and it still lit off after a couple of cranks. And that was with 20W50 dino in the sump.

[GregFeeler]

If your temperatures are mostly below 80F in the winter, Rotella 5W40 is a good starting oil. Really transforms cold weather operation. If you get stuck in traffic a lot and hit 6 or 7 bars this might not be a good choice, but for me it works great.

Rod

It's your bike, but there's nothing I've seen in any BMW motorcycle manual that recommends ever using a 5w oil - especially in temps as high as 80F. My Jetta recommends that type of oil, but car and bike oil requirements are very different, at least according to the manufacture's recommendations.

As to the question at hand, a big displacement twin cylinder engine is never going to spin up like a three cylinder engine 35% smaller. Many engines *sound* like they are laboring to start when that is just how they are designed. Still, a good quality fully synthetic oil should help significantly in cooler weather - say from 40F down in particular.

[kbasa]

Two 625cc pistons will never get up to speed as quickly as three 250cc pistons.

Keep your bike in good tune and be absolutely compulsive about getting the valves set *perfectly*. A good, careful TB synch and it should fire right up.

Be sure to pull the clutch in, as well. Your poor starter is trying to push those two big cylinders through compression while it's trying to spin up the transmission. I learned on airheads that you really need to pull the clutch to get the transmission and lube out of the way on chilly mornings.

On the other hand, your oilhead will never weld the starter relay shut and grind your battery down to nothing on a cold day. Nor will it stupidly keep pumping fuel in there to foul your plugs. :ha

[JHGilbert]

Thanks guys. I usually start with the clutch disengaged to help the starter. Syn oil will probably get swapped in October. The valves and TBs will be taken care of this weekend and I'll see what difference that makes.

[breyfogle]

An R11xx will never start as quickly as a K75. The starter just does not spin the motor fast enough and the EFI is probably set too lean for quick starting. But, what works for me (I have absolutely no way of knowing why thus works, or if it works on any bike other than mine !) is to crank the engine two or three revs, stop, and press the starter a second time. The bike never starts with the first try but fires almost K-bike like with the second try. YMMV

[JHGilbert]

That's almost exactly how mine starts. Staying on the starter the first time doesn't seem to work at all. But the second time I hit the starter it will begin to fire. The fuel pump cycles for about a second when the ignition is turned on and one BMW mechanic suggested I cycle the pump twice before attempting to start it, but I didn't notice any difference in starting ease. I'll retest this morning.

[bjm]

K bikes sure do give a rider much more confidence when starting. Even though my R1100R has never let me down it always sounds as if it's laboring to start. Boxers are much more finicky than the bricks.

[OfficerImpersonator]

Put your daily rider on the tender every night and you'll never have to worry about the bike not starting the next day, or in exceptionally cold weather.

I ride my 1150 RTP year round, often in sub-freezing temperatures, and I've never had my bike not start, or have trouble starting. When it's cold outside, and I'm running heated grips, at least one set of auxiliary driving lights, a radar detector, maybe a GPS/iPod, and my zillion marker lights, I know my alternator won't replace all those lost electrons, so the bike goes on the tender every night, year round.

When my bike starts to hesitate/sputter in low gears/low RPMs, that means she's about due for a Level II and new plugs, throttle body sync, fresh oil and new filters. After a Level II, she runs as smooth as a brand new R1200.

[kbasa]

K bikes sure do give a rider much more confidence when starting. Even though my R1100R has never let me down it always sounds as if it's laboring to start. Boxers are much more finicky than the bricks.

Getting my K75 started on a cold spring morning always filled me with dread. You'd be amazed how fast you can get the ground cable disconnected when the relay welds itself shut. :ha

[Mr. Frank]

I use the two stage start as well. I turn on the key and wait for the ABS light to stop flashing. Then I hit the starter for a couple of seconds and then release. The second stab on the starter fires it right up/

[jingdog]

Try starting an F650 FI and youll LOVE the 1150!

[MikeWillison]

Another two stage starter here. I thought it was just something strange about my 1998 R1100gs but apparently not. It never fires right away on the first crank. Stop for a moment & it will fire right up on the second attempt. Go figure?

[JHGilbert]

Try starting an F650 FI and youll LOVE the 1150!
I thought about an F650. Once I figured out what was required for an oil change I decided on the R1150.

I suspect the lean burning engine is the problem with slow starting, as has been proposed in the past. In my Toyotas, past and present, there is a additional injector in the manifold to richen the mix on cold starts. I'm not sure why the double start method works better than a single start. I haven't found any significant difference in starting ease cycling the fuel pump twice before starting. It would be interesting to put a fuel pressure gauge on the line and check the pressure at startup.

[breyfogle]

I'm not sure why the double start method works better than a single start. I haven't found any significant difference in starting ease cycling the fuel pump twice before starting.

My guess is that cycling the fuel pump doesn't cause the injectors to squirt any fuel but hitting the starter button does inject some fuel into the intake track. Stopping and starting may enrichen the mixture just a bit to help starting.

[jingdog]

I thought about an F650. Once I figured out what was required for an oil change I decided on the R1150.

.


Oil changes on the F650 FI are a snap if you use a transmission oil pump to siphon the oil from the oil tank. $10 from Pep Boys...

[JHGilbert]

Did it all this weekend. Cam chain tensioner, valves, throttle body sync (includes throttle cable sync). It definitely runs better and the surging is much improved, but there is still a bit of surging.

I think I figured out why the oilheads have the surging problem. Monotronic FI treats the twin like a single cylinder, injecting two half-charges of fuel into both manifolds. One is injected into the intake during the exhaust cycle and the charge sits there until intake cycle when it gets another half-charge.

The injection computer takes its readings from a single O2 sensor and makes its calculation based upon the exhaust coming from the pluses from each cylinder. The Monotronic FI computer assumes that the reading is coming from a single cylinder, not from two cylinders. So the closer to identical the functioning of the cylinders, the more stable the Monotronic's program.

If the right cylinder is not identical in throttle body opening, valve opening, intake charge, etc. then the Monotronic is reading the O2 sensor, and adjusting the mixture to compensate, which adjusts the left cylinder out of range, which the Monotronic readjusts for, leading to the surging issue.

In short, since the Monotronic thinks the 1100 and 1150 are single cylinders, the cylinders have to behave as close to identical. Thus the sensitivity of the engines to proper valve adjustment, throttle body adjustment, and throttle cable adjustment.

That the surge is most dominant at certain RPMs leads me to believe that it may also be related to the frequency of O2 readings/mixture adjustments by the Motronic. Above those RPMs, say 4000, the exhaust pulses are occuring faster than the readings by the Motronic and the computer is getting a true average for both cylinders.

Discussion?

[jingdog]

Discussion?


Yeah why do people spend $15,000 for a BMW motorcycle that runs like a piece of crap?

[mneblett]

I think I figured out why the oilheads have the surging problem.

<<snippage>>

Discussion?
It's really much simpler than that -- for emissions reasons, they are "jetted" (programmed) very lean at small throttle openings (which just happens to be where emissions tests are run -- not a coincidence).

That's why anything that can help provide more consistent combustion (such as alternative spark plugs, proper valve clearances, etc.) helps minimize the random failures to ignite a too-lean mixture (these "misses" are the source of the surge -- the uneven power production accompanying the dropped combustion cycles sets up the pulsing in the engine's power output).

Due credit for the interesting theory/thought experiment, but while the later Moronic computers are faster than the one in a 1983 K bike, the one on the oilheads still isn't fast enough to be able to evaluate individual cylinder pulses and correct the other cylinder before its next suck/press/bang/blow cycle. The actual closed-loop read/response cycle effectively results in an averaged exhaust O2 content reading, and adjustments to both cylinders' fuel injections at the same time.

[Mr. Frank]

BMW motorcycles run and ride very well. They sometimes break or fail at bad times.

[kgadley01]

I've never had a problem with cold weather starts. then again my garage is heated, and I live in South Carolina. :whistle

[kbasa]

Did it all this weekend. Cam chain tensioner, valves, throttle body sync (includes throttle cable sync). It definitely runs better and the surging is much improved, but there is still a bit of surging.

I think I figured out why the oilheads have the surging problem. Monotronic FI treats the twin like a single cylinder, injecting two half-charges of fuel into both manifolds. One is injected into the intake during the exhaust cycle and the charge sits there until intake cycle when it gets another half-charge.

The injection computer takes its readings from a single O2 sensor and makes its calculation based upon the exhaust coming from the pluses from each cylinder. The Monotronic FI computer assumes that the reading is coming from a single cylinder, not from two cylinders. So the closer to identical the functioning of the cylinders, the more stable the Monotronic's program.

If the right cylinder is not identical in throttle body opening, valve opening, intake charge, etc. then the Monotronic is reading the O2 sensor, and adjusting the mixture to compensate, which adjusts the left cylinder out of range, which the Monotronic readjusts for, leading to the surging issue.

In short, since the Monotronic thinks the 1100 and 1150 are single cylinders, the cylinders have to behave as close to identical. Thus the sensitivity of the engines to proper valve adjustment, throttle body adjustment, and throttle cable adjustment.

That the surge is most dominant at certain RPMs leads me to believe that it may also be related to the frequency of O2 readings/mixture adjustments by the Motronic. Above those RPMs, say 4000, the exhaust pulses are occuring faster than the readings by the Motronic and the computer is getting a true average for both cylinders.

Discussion?

Autolite 3923 plugs.

Trust me on this one.

[mneblett]

Autolite 3923 plugs.

Trust me on this one.
+1 :thumb Definitely helped my '99 R11RT, many moons ago.

[kgadley01]

Autolite 3923 plugs.

Trust me on this one.

+2 :thumb

[JHGilbert]

Autolite 3923 plugs.

Trust me on this one.

I've had them since I first noticed the surge. Even sprung for the Iridium. Still surges, although not as bad. I must be getting closer.

On the plus side, after tuning it this last weekend it fires off on first crank most of the time now. Even after sitting all day long and without the fast idle. I'm getting closer. My touch with carbs and valves was learned on antique cars and will probably have to improve.

[rado360]

Just my 2 cents,I heard a dealer tell a customer that the r bikes were programed to crank over twice before they fire,I've been told some airplane engines do this too. .

[rinty]

A good start on an airplane engine is one taking fewer than 10 blades...:D

...in summer...

[jcridge]

Really good discussion with only the occasional off comment...

The 2 start success comes from a few things. First time you crank to start, the ECU (Fred) needs to find TDC, air temperature and with luck voltage above 10.5 volts. So if you only hit the button for a second, it may not catch and start. Now when you hit the button the second time, the injectors have already sprayed the back of valves and intake with fuel from the first attempt so you are already in an enriched state and therefore a quicker start up.

Having the T/B throttle plates clearances and cable adjustment equal is critical to making this all happen. Not to mention a good battery...remember the ECU and ignition coils like to see voltage above 10.5 volts.

The factory O2 sensor should not play a role in start up, I don't know this for a fact with BMW but start-up is usually based on hard code programming and temperature and not dynamic feedback from the O2. So the Techclusion box would not play a major part in start-up other then possible providing a slightly longer injector duration, and that's only if the ECU is looking for the feedback to start with, which I'm not sure it does.

On a secondary level, the first crank splashed oil on the cylinder walls and passages so you are technically floating the rotating components in oil now and not resting on the thin film.

And lastly, the K75 is as good as it gets.............

[rinty]

I never had to use the double start method on my '02 Oiler, but it was an effective technique on my '82 airhead RS, which could sometimes be cranky on it's annual post winter start.

I would crank it over about 10 rotations and if it didn't fire, just leave it for 5 minutes, after which it would usually light off.

[GSAddict]

I've had them since I first noticed the surge. Even sprung for the Iridium. Still surges, although not as bad. I must be getting closer.

On the plus side, after tuning it this last weekend it fires off on first crank most of the time now. Even after sitting all day long and without the fast idle. I'm getting closer. My touch with carbs and valves was learned on antique cars and will probably have to improve.

The 3923 is for the 1100's
If yours is an 1150 you should be using the 3922 (1 level colder)

[mneblett]

The factory O2 sensor should not play a role in start up
It doesn't (and can't). O2 sensors must reach a temperature of a few hundred degrees before they provide a usable signal, so they are useless/not functional at cold starts.

[DarkCloud]

How do you cool down the engine before shutting it down?

[JHGilbert]

The 2 start success comes from a few things. First time you crank to start, the ECU (Fred) needs to find TDC, air temperature and with luck voltage above 10.5 volts. So if you only hit the button for a second, it may not catch and start. Now when you hit the button the second time, the injectors have already sprayed the back of valves and intake with fuel from the first attempt so you are already in an enriched state and therefore a quicker start up.

Having the T/B throttle plates clearances and cable adjustment equal is critical to making this all happen. Not to mention a good battery...remember the ECU and ignition coils like to see voltage above 10.5 volts.


I never thought about the ECU having to find TDC.
So the only richening mechanism on the injection is the lack of signal to the ECU, (which causes the ECU to default to its fail-safe hard programming) and the half-injection charge that is sitting in the intake? And it takes a revolution of the engine, before the ECU knows when to time the injection.

It's beginning to make sense.

[JHGilbert]

How do you cool down the engine before shutting it down?

No cool down. Off the Interstate or the access roads, into the neighborhood, about 3 corners, into the drive, turn off the engine, open the storage/glove box, hit the garage opener, close the glove box, pull into the garage and shut 'er down.

On an air/oil cooled engine, I think the cool down is probably not necessary. Unless, of course, you have to endure stop and go traffic on a 100 degree day. But because of my schedule, I rarely have much stop and go traffic. But during one hot day when the temp guage got up there, I noticed it took quite a distance (few miles) before it came back down.

[jcridge]

It doesn't (and can't). O2 sensors must reach a temperature of a few hundred degrees before they provide a usable signal, so they are useless/not functional at cold starts.

Yeah, more then likely that is how BMW is managing the system, but O2 sensors and their modern counterparts AF sensors can read at any point, it's up to the mapping of the ECU when it controls from their input. The ECU always looks at the signal and usually bases the control point using a temperature sensor. The earlier emission systems were not closed looped and used the O2 as a coarse trim to protect the cat. The newer closed looped systems are very efficient at controlling the pulse width and vary it to a much greater degree based on the O2/AF signal.
Lighting off the cat is done quickest by enriching when cold, so most companies just let the hard code cold start mapping run until a predetermined temperature and or time has been reached, then it will close the loop and look to control based on the O2/AF signal for best stoichiometry.

Back to the thread, kept track of our 1100 start time last few days counted the time it takes to start and 3 seconds seem to be the norm on the first try. Pretty much the same on every try after that, maybe a second less. No second trys needed.

A good battery and state of tune are the key to easy starts.

[JHGilbert]

SUCCESS!!!

How do you get a R1150 to fire off like a K75? Get rid of the gel cell battery and get a Shorai battery (http://www.shoraipower.com/c-1-batteries.aspx). I've had the battery for about 3 or 4 months and installed it today without charging it. It still spun the engine faster than 2-3 year old gel cell (even after charging). Not a little bit faster....A LOT FASTER. Between getting better at tuning the boxer, new battery and Booster Plug the 1150 explodes to life, runs smooth, without vibration and surge free.

I'll report how the new battery handles El Paso's heat...It's gonna be a hot one this year.

[DarkCloud]

SUCCESS!!!

How do you get a R1150 to fire off like a K75? Get rid of the gel cell battery and get a Shorai battery (http://www.shoraipower.com/c-1-batteries.aspx). I've had the battery for about 3 or 4 months and installed it today without charging it. It still spun the engine faster than 2-3 year old gel cell (even after charging). Not a little bit faster....A LOT FASTER. Between getting better at tuning the boxer, new battery and Booster Plug the 1150 explodes to life, runs smooth, without vibration and surge free.

I'll report how the new battery handles El Paso's heat...It's gonna be a hot one this year.

What brand of gel cell was it? Did it fail, or did you change it out as a sceince lab project? Jon

[JHGilbert]

I would call it a soft-fail and it was a "WERKER" gel cell. When I got the RT in Aug 2009 (If I remember correctly), the PO said he had recently put the new battery in. Beginning last fall, my clock would reset occasionally, which I narrowed down to startups (its my primary commuter). The engine would always crank and start, but the starter always seemed to strain to turn the boxer over.

I also thought by buying a Battery Minder with de-sulphating capability, I might be able to resurrect the gel cell. Nope. The clock was still resetting with restarts this spring, though its nice and warm down here.

I bought the Shorai, and was saving it for my 42K tuneup, which I did today. HUGE difference.

[JHGilbert]

Followup:

Too many bikes in the garage this winter plus the car, so I had to leave the R1150RT outside a few nights till we got everything rearranged. Still, even after sitting out on frosty nights, it would fire right up for the morning commute. It cranks like a demon and there is no clock reset. We'll see how it cranks after a few years, but right now it's an awesome battery.

[GregFeeler]

Followup:

Too many bikes in the garage this winter plus the car, so I had to leave the R1150RT outside a few nights till we got everything rearranged. Still, even after sitting out on frosty nights, it would fire right up for the morning commute. It cranks like a demon and there is no clock reset. We'll see how it cranks after a few years, but right now it's an awesome battery.

That's good to hear. Do you have to "heat" the battery by turning on some lights or accessories - or is what you describe from a dead cold start?

[JHGilbert]

My light switch is nearly always in the "on" position (European switch). I just turn on the ignition, put the kill switch in "on" position and start it. I usually don't even use the fast idle lever. No heating, no trickle charge, no prayers. It just cranks and starts.

[GregFeeler]

My light switch is nearly always in the "on" position (European switch). I just turn on the ignition, put the kill switch in "on" position and start it. I usually don't even use the fast idle lever. No heating, no trickle charge, no prayers. It just cranks and starts.

Nice! :thumb

[JimMoore]

Discussion?

On an R1100 you can pull your cat code plug, which will take the O2 sensor out of the loop. On an 1150, you have to disconnect the O2 sensor. You might want to try that. It really helped the surge on my R1150GS.

[Happy Wanderer]

On an R1100 you can pull your cat code plug, which will take the O2 sensor out of the loop. On an 1150, you have to disconnect the O2 sensor. You might want to try that. It really helped the surge on my R1150GS.

Jim, I'm disappointed. I always look forward to the "throw it off a bridge" part of your surging advice. It makes me laugh every time. :)

[JHGilbert]

No surge now Jim. Simply a matter if becoming more proficient at tuning the 1150. Pulling Cat-code plug runs the bike in limp-home, fail rich mode and will eventually kill the cat. It's not necessary if you tune it properly. In fact, when mine starts surging again, I use it as a sign that it's time for a tuneup.

[ANDYVH]

My 94 RS has started fine up here in Green Bay since Oct 94 when I brought it home. Unheated garage, or sitting out overnight it starts by the third crank with no "start cycles" of ignition on-off-on. No special "cool down" needed either.

About four years ago I rebuilt the starter to re-attach the loose magnets back in the starter housing. That made a huge difference in cranking speed and starting ease. Same for a Battery Tender, keeping the battery up is crucial to avoid ABS faults on startup due to low battery voltage.

Prior to installing a Techlusion to go with my home built muffler I did all the usual stuff, Autolite 3923 plugs, charcoal canisterectomy (that was over 150,000 miles ago). K&N filter, etc. I never had any surging problems with my RS even though it is a very early US model (no CAT code plug at all, never had one).