Valve adjustment results in rough start but smooth when warm

[cgguy09]

Hey boys,
2004 R1150R Rockster ABS. To start, I think I know what the problem is, I'm just trying to understand why it would be this way...sort of a dialectic question.

I adjusted my valve at 15.8k miles...hadn't been done up until this point. Before my adjustment, the Bike started up with no issues and idled immediately at 1.1k rpm, the choke or secondary idle (call it what you will) was right about at 2k. Occasionally I would notice a soft "clacking" when at low rpm at or around start up. (A sound I know well from my old cb350 of improper valve movement.)

I adjusted the valves in accordance with the official manual and online knowledge. To start, the "clacking" is gone. But the bike has a rough start, and for the first couple minutes idles at 900 rpm and ~1.5k rpm (secondary or "choke"). Once it warms up. It's right where it needs to be. 1.1k rpm and 2k rpm (secondary). Sounds good, rides good, doesn't die, doesn't surge.

I'm guessing it's because the valves are a little too tight ( I err'd on being more tight than loose). My plan is to go back and redo them all. But I was curious about why it's perfect when it warms up but really rough at start-up.

As far as other information goes, the temps are mild (mid 60's) I replaced the air filter two weeks ago, the fuel likes with replaced 2k miles ago, cali-canisters were removed. So I would like to rule out an "unmentioned variable" as the cause for the difference.

Thanks for helping me understand this beautiful machine.

-cFogs

BT
NNNN

[cgguy09]

One more note...the spark plugs were replaced at the time of valve adjustment. I replaced them with the OEM Spark Plugs procured from Gateway BMW in St. Louis.

Thanks!

BT
NNNN

[towerworker]

I've always understood that it's better to adjust valves a tad too loose rather than too tight. I think that's what is happening here. When cold the valves are too tight resulting in the idle issues, when warm everything has expanded a bit along with the valve tolerance which I think puts the valve clearances where they should be which is demonstrated by the correct idle. I am certainly not an authority here but I have also read that running them too tight can ultimately result in some engine harm.

Good luck!

Wayne

[CycleRob]

cgguy09,
I read in your still visible Sept 30th "maintenance and oil changes" post that you changed the air filter, leading me to suspect you may have disconnected the battery terminals for cleaning -or- less likely, to top off a previous generation flooded cell conventional battery. If you did disconnect either/both battery terminals without resetting the Motronic computer's TPS parameters after reconnection, the engine would run erratically the way you describe and they would not be reset until the full throttle stop was reached while riding.

Setting the valve clearances too tight may be a conbtributing factor if you used the metric .15mm and .30mm feelers, but it will not be a factor if you used the easily available .006" and .012" (.152mm/.3048mm) feelers. I suspect the replacement "OEM sparkplugs" (dual electrode) as the major contributor. If the old sparkplugs were the conventional single ground electrode type (and they can be one heat range hotter), reinstall them and see if things improve.

.

[riceburner]

Did you do a TB balance as well?

[billbeemer]

put the old plugs back in and try. plugs, regardless of what cash hungry dealers may say, will go 50k nowadays. if old plugs give same results, synch throttle bodies with tool from boneyard. oh, btw, use a wire guage to reset new plug clearance to .030". most plugs aren't set correctly from the manufacturer.

[cgguy09]

Thanks for all the comments guys,
As soon as I got home today, I began working on the bike...of course I didn't check the forum first. DOH!

So I readjusted the valves & that seemed to do it...well, sort of. it now smoothly idles at 1050~1100 on the "low idle" on the fast idle it is about 1.7k-1.8. I didn't really let it warm up for that long, maybe a minute 2 at the most. I know the 1.8k is roughly in the acceptable range for the high idle. But, I really wasn't satisfied. I feel the "high" idle was higher before and I've heard of people setting the HI to 4k. So I checked r1150r.net and...boom, all your comments

To answer the questions posed:
Spark Plugs: I switched them out after the recommendation and it had no apparent effect. (I did buy them from BMW and they said they were correctly gapped for my year and model).
Battery Connections: (Good catch on the previous post! I appreciate the attention to detail!) I was able to swap the air filter with the gas-tank on (it wasn't easier). So I don't believe it would apply. But that is great information because the battery terminal greasing is coming up this weekend.
Throttle Body: I currently have not sync'd them...something on my list. Would anything I have done up to this point (valves, spark plugs, air filter) have affected the TB sync? (I'm asking because I don't know).
Feeler Gauges: I have the Yellow/White Pair from Beemer Bone yard and did the adjustment by the JVB dvd and the numerous other guides out there.

Things I failed to mention previously, but things I don't think would have had an impact:
Did my 6 month filter/oil change and switched to the BMW Brand 10w-40 winter blend (dino). It was previously AMSOIL 20W-50 Synthetic. Also, I ditched the BMW Filter for a K&N model. I doubt these would impact anything but wanted to lay it out there.

One other note, she's really low on gas...I know the BMW's have fuel pumps, so I don't know if that would be a causal issue. On the ol' CB350, she needs at least a half tank to run right. (I haven't filled up the Rockster because I was testing my range and it's been raining the last 4 days in STL)..but tomorrow I'm filling her up.

Thanks for the information & hopefully I'll get this figured out!

Take care, guys!

[riceburner]

Throttle Body: I currently have not sync'd them...something on my list. Would anything I have done up to this point (valves, spark plugs, air filter) have affected the TB sync? (I'm asking because I don't know).

The perceived wisdom is yes, it can. Remember the first part of TB sync is the BBBA screws - which control..... wait for it..... the balance at IDLE SPEED! So - once you've checked the valves (with a COLD engine), take the bike for a run to get it warm and then put on your manometer and check the balance at idle and adjust the BBBAs (it also helps to clean them before hand* ).

One other note, she's really low on gas...I know the BMW's have fuel pumps, so I don't know if that would be a causal issue. On the ol' CB350, she needs at least a half tank to run right. (I haven't filled up the Rockster because I was testing my range and it's been raining the last 4 days in STL)..but tomorrow I'm filling her up.

Quite possibly, the fuel at the base of the tank will be the most contaminated with moisture (if there's any there) and also it's where any detritus will be. Get the tank at least half full to ensure you're drawing from decent fuel.




* I'm sure there's a better description of the BBBA cleaning method but basically you need to unscrew them, BUT remember exactly how many turns it took to take them out, because you need to put them back in the same amount and then rebalance at idle. (IIRC)

[cgguy09]

Thanks for the info RiceBurner...I'll being making a manometer this weekend.

Update:
So I started it up the morning and it idled at about 900~1k rpm and 1.4k on the high idle. I rode it 1/4 mile to a gas station and filled it up (4.3 gallons). At that point it idled at 1.1k and 1.8k High Idle. (just where I like it) I then rode it for 7 miles (at all ranges of speeds and rpm's). At the end the bike idled at about 1.1k-1.2k and high idled at 2.1k-2.2k.

So I'm guessing based on that information I think my problems were caused by both the low fuel level and valves that were adjusted too tight.

I am happy with these results. But I still intend to balance the TB this weekend or at least build the device.


Thanks for the help boys! Keep those gas tanks filled!

cFogs OUT

BT
NNNN

[MarkShelley]

Glad you have the problem sorted.
Don`t worry so much about the high idle revs. The high idle is just a cable that opens the throttle a small amount, nothing complicated. It is NOT a choke that affects the mixture as on most bikes.

Incidently, when you do the TB balance and remove the brass tick-over adjustment screws for cleaning, rather than counting the number of turns to remove them you should count the number of turns the opposite way until they are fully seated......then remove them. This is more accurate.