Very hard cold start on a 2012 RT

[AjaxTheDog]

I bought my 2012 RT in late spring of this year and its a great bike, runs fine and has been no trouble. However as the weather has changed it is becoming increasing harder to start with colder temperatures. It will not start below 50 degrees F at all unless I crack the throttle about 1/3 to 1/2 open, and even then it dies a two or three times before I can keep it running to get it warmed up. Once I do get past the cold start it runs roughly by itself with no manual throttle only after a couple of minutes. After it is fully warmed up there are no issues whatsoever. The starting sequence gets progressively harder as the temperature drops.

I bought the bike with 7200 miles on it. I performed the 12K service myself and meticulously checked the spark gap to make sure it was on spec before installing the plugs. The bike now has about 16,750 miles and is still under warranty. I can give it to the dealer but he'll have to keep it overnight and to be honest in the past I have found their diagnostic skills to be rather underwhelming, especially if it is a warranty gripe.

I have ruled out gas as a cause, since I have been through many tanks from different stations since the problem started. I doubt it is the plugs since they have less than 5K miles on them. It feels like I am trying to start a motor that has no choke, so I suspect whatever sensor tells the engine to supply extra gas for a cold temperature start is lacking. I have the GS911 tool but honestly I am not sure what I'd look at for that to help.

So I could use some diagnostic suggestions. I did try the trick to turn on the ignition and open the throttle 3 times then turn it off and that did nothing. I think I have done this half a dozen times just in case, with no change in starting performance. I am thinking its got to be some kind of sensor that is not transmitting the right temperature information, but not sure which that could be or how to prove that theory. Any ideas are appreciated, thanks.

 

[lkchris]

It's designed to start without you having to open the throttle.

Some component has failed or you have vacuum leaks.

 

[AjaxTheDog]

Gs911

It's cold here today so I just plugged in the GS911 and it said no engine fault codes. Also showed temp input values for air and motor at 5.3C, which is correct. Tired to start with no throttle and it won't. I think I'll just call the dealer.

 

[marchyman]

It's cold here today so I just plugged in the GS911 and it said no engine fault codes. Also showed temp input values for air and motor at 5.3C, which is correct. Tired to start with no throttle and it won't. I think I'll just call the dealer.

Have you looked in your riders manual? On page 66 for the one dated 08.2011, 3rd edition. It says:

For cold starts and at low ambient temperatures: pull the lever to disengage the clutch and twist the throttle grip slightly.​

Yeah, "low ambient temperature" isn't very precise.

 

[roger 04 rt]

It's cold here today so I just plugged in the GS911 and it said no engine fault codes. Also showed temp input values for air and motor at 5.3C, which is correct. Tired to start with no throttle and it won't. I think I'll just call the dealer.

If you're interested, turn your key on, connect the GS-911, set to monitor all real time values and then select log to CSV file. Try starting normally and if it doesn't then twist the throttle as you have. Don't turn the key off. Run for 5 minutes. Stop the log and PM me and then you can email me the log. I'm very used to reviewing the files, maybe something can be seen in the log. It would only take about 15-20 minutes to see if anything jumps out.

RB

 

[roborider]

I'm very used to reviewing the files, maybe something can be seen in the log.

RB

Nice offer, we really have helpful people here.

I'd like to know what you find as the cause, whether on your own or from a dealer. This problem has been raised before. My 2005 R12RT has just over 70k miles. I was in the mountains this weekend. We departed and it was 34 degrees when we left, the bike sitting out all night. I cracked the throttle and it started on the second attempt. Close the throttle and it was fine on its own. If an 8 year old bike, with 70k miles, works like that, then you have a problem, for certain.

 

[LngRdr]

RT starting

I have to crack the throttle a bit on my 12 RT when it's cold. Ran the battery down in a Glacier before it dawned on me. No problems since.

 

[AjaxTheDog]

Dealer says...

Rog, I just may take you up on that offer, thank you.

I called the dealer and they said they could reset the adaptation values and put in some fuel cleaner. Hmmmm...2 year old bike with 16K miles, so the fuel cleaner idea struck me as rather odd. I don't think my system is dirty, just too soon for that. So I looked at the GS911 again and saw I could rest the adaptation values myself. Shame on me that I didn't know that could be done. I did the reset but weather has not been cooperative here to ride it and see what that did. Probably early this week I will.

Just for the record this is not a "crack the throttle open a little" problem, this sucker is just plain hard to start when its cold out, like < 50 degrees F. It takes cracking the throttle well beyond a little bit and then juicing it when it catches, usually stalls 2 or 3 times before I can keep it running. Then when its running after that I have to keep the throttle open for a minute or two or else it will die. After a couple of minutes it stays running. When warmed up its the happy camper, no issues.

I should know in a few days...

 

[JoeDabbs]

28 F out this am...pulled clutch in, hit starter button, fired right up - no twisting of the throttle. Of course, it cranked a bit slower due to cold oil, but caught in about two seconds.

 

[roger 04 rt]

Rog, I just may take you up on that offer, thank you.

I called the dealer and they said they could reset the adaptation values and put in some fuel cleaner. Hmmmm...2 year old bike with 16K miles, so the fuel cleaner idea struck me as rather odd. I don't think my system is dirty, just too soon for that. So I looked at the GS911 again and saw I could rest the adaptation values myself. Shame on me that I didn't know that could be done. I did the reset but weather has not been cooperative here to ride it and see what that did. Probably early this week I will.

Just for the record this is not a "crack the throttle open a little" problem, this sucker is just plain hard to start when its cold out, like < 50 degrees F. It takes cracking the throttle well beyond a little bit and then juicing it when it catches, usually stalls 2 or 3 times before I can keep it running. Then when its running after that I have to keep the throttle open for a minute or two or else it will die. After a couple of minutes it stays running. When warmed up its the happy camper, no issues.

I should know in a few days...

Hi Bill,
I find these diagnoses all interesting. I'm helping an '04 R1150RT owner with a problem. Very tough symptoms. He logged some data (below) and we could quickly see the reason for his poor cool temperature idle--lean mixture (lambda sensor voltage) and unstable spark advance green line, top chart.

It still was hard to sort out cause and effect. I got it wrong at first but at least we were progressing systematically.
Roger

 

[roborider]

Would like to hear more on that graph. I assume the lambda line is not correct in the first third, then ok at the last 2/3. Not sure what the green line should look like, but I guess spark advance should be pretty stable at idle?

 

[roger 04 rt]

Would like to hear more on that graph. I assume the lambda line is not correct in the first third, then ok at the last 2/3. Not sure what the green line should look like, but I guess spark advance should be pretty stable at idle?

If you squint at the chart in the earlier post you can see the line called lambda closed-loop control which is a reported function on the Motronic ECU but not on the BMSK. When the lambda sensor voltage is about 450 mV the sensor is too cold to work. Then it heats up enough to function and because the mixture is rich while the engine is still cold the sensor goes to about 900 mV. That's where it should stay until the Motronic is running closed loop. However, when the fast idle lever is reduced you can see the lambda sensor voltage drop, not good, and also the spark advance is moving rapidly between 7-12 degrees BTDC. It should be steady at about 7 degrees.

The cause of this "leanness" and unstable advance is that the engine started to miss, sensing unburnt fuel and unconsumed oxygen into the exhaust. When the bike goes closed loop, lambda sensor voltage switches up and down between 100 and 800 mV due to the Motronic moving the mixture a little lean, then rich, then lean--as it does.

The chart below shows the spark advance after the owner cleaned the throttle bodies and adjusted the idle speed. It would further improve if the idle speed was adjusted upward a bit or if the fast idle lever was left on for another minute.

 

[roborider]

Nice. I need to collect some data on my R12RT while it is running well as a baseline for future reference.

 

[roger 04 rt]

Nice. I need to collect some data on my R12RT while it is running well as a baseline for future reference.

That's a really good idea. Set up logging to a CSV file, when your bike has sat overnight. Then turn the key on, enable logging and run till the bike is warm and in closed loop, about 3-4 minutes. That way you'll get a baseline for how your bike starts. It's a valuable tool.

 

[roborider]

Did you ever get the cold start resolved?

I'm starting a new thread on what I (with Roger helping) discovered on my RT. Post here:

http://tinyurl.com/pg5mx88

 

[43883]

Some bikes have this issue and other bikes don't. On a recent trip to Alpine, TX it was 36 F in the morning and out of 4 BMWs 2 had problems including mine. The trick on my bike is crack the throttle very little with one hand and press the starter button with the other hand. I mean barely open it and give it try. After that I started the bike at 32 F with little problem.

Btw, two of the bikes are identical and purchased at the same time and one has the issue and the other does not. We were parked side by side and his bike started right up and mine refused to start. Go figure.

tsp
My blog: http://www.airheadmoto.com

 

[roborider]

Some bikes have this issue and other bikes don't.

Yes, but there is still a REASON for this, and a good mechanic will eventually figure it out.

 

[roger 04 rt]

Some bikes have this issue and other bikes don't. On a recent trip to Alpine, TX it was 36 F in the morning and out of 4 BMWs 2 had problems including mine. The trick on my bike is crack the throttle very little with one hand and press the starter button with the other hand. I mean barely open it and give it try. After that I started the bike at 32 F with little problem.

Btw, two of the bikes are identical and purchased at the same time and one has the issue and the other does not. We were parked side by side and his bike started right up and mine refused to start. Go figure.

tsp
My blog: http://www.airheadmoto.com

In a thread I initiated named "Starter or Battery" in the Oilhead forum, I documented the sensitivity of the R1150's Motronic to spikes on the +12V bus caused by increasing battery resistance, caused by undercharging. It's hard to believe the diagnosis at first but i came at it from several angles to reach the diagnosis. After reconditioning my pc680 battery with 6 full discharge/recharge cycles, the bike now starts in 1.5 seconds or less, fast idle lever untouched in the detent position. I've tested the starting performance for over a month now in temperatures from 20F to 60F.

Whether these issues are battery related or not, I don't know. The key to cornering the issue is regular collection of starting data by logging the GS-911 to a CSV file. Glad to help if anyone collects the data.

 

[racer7]

the problem strongly suggests either a vacuum leak or funky battery.

If you're using an AGM, note that the RT charging voltage is 14.1 to 14.3 on most- so a maintainer at higher voltage is advisable when home.

And of course, the OEM battery is a marginal at best piece of junk in the real cold. Why anyone would pick a modestly sized GEL for a cold weather starting battery on a bike with a high current demand for starting isn't very obvious..

More than one has had the throttle body plug or a vacuum hose left off during a service. Look and see if they're there and attached. This problem would be most obvious in cold starts.

 

[rapiddog]

I'm having the same cold start problem. Even with a brand new battery. Not sure if it's got alot to do with the cold or not.
I've heard 'vacuum leak' a couple times.
What sort of leak and where would I look?