Cold Start Problems

[Riverside]

My 2004 R1150R with 16000 on the clock, after recovering from a tapping noise that turned out to be the rocker arm end float had a TB syncho done recently. Now I suddenly have a cold start problem. When I got it back from the sync on Wednesday I put a few miles on it to get it warm and see how everything felt. Responded as you might expect it to. On Thursday I started it and there was a few moments of rough running that seem to be solved with the twist of the wrist a few times and once out on the road for mile or so it was fine. Next time I got to ride was Tuesday morning. Cold start was very difficult. Had to restart it several times using additional throttle and when started it sounded like it was running on only one side. Again warming it up after about a mile and at higher RPMs it sounded smooth and even. This did not happen before the TB sync. Any ideas what I should be looking at first? It sounds like one cylinder may not be firing cold. Is there a test for the stick coil to see if it is working to full capacity? Or is there something simple I need to check to see if something was left unplugged etc after the TB Sync?

[kirby]

When you pull the cold start lever, watch and see that the throttle wheel where the cable connects at the throttle body is moving a small amount, maybe a 1/16 th of an inch in the first position and a bit more (small bit) for the high position.
Watch one side first then do the same on the other. They should be the same. This engine doesn't react very well to manual inputs and is easily flooded during start.

If you were to check the TPS with a meter the low position is about .4v and .8v for the high position. +or- a little (the way mine are set)

Don't know how you did the syn but if you messed with the throttles cable(s) you may have changed the start lever settings. They can be adjusted at the handlebar.

On real cold wx starts (cold soak below 20 deg I have a small can of starter fluid (aerosol) and use a SMALL amount in the intake horn before start(not much).

mike :-)
edit:
Make sure the throttles are closed against the stops with no throttle input. If the machine is idling correctly when warm they most likely are

[sstein]

Make sure the throttle cable sheath was/is not dislodged from the nut where it reaches the right throttle body.

[Riverside]

Kirby may be on to something. The right side throttle wheel does not move when the cold start is engaged, but, the left side does. This would provide the engine an unbalanced fuel delivery. I would think this would also cause an unbalanced situation with the TBs under load. Going to run over to the shop to see what he did when balancing the TBs and have him make the adjustment to the cold idle lever to make that right first. If it still persists I will try the other suggestions. And just an FYI... cold starting here never involves 20 degrees. I'm in the San Diego area so cold is 50 degrees.

[kirby]

The cold start lever cable is tied to the boden bell crank mounted under the airbox. The throttle pulls a single cable from the handlebar which is tied into the boden mechanism which in turn operates a short cable to each throttle body.
If you change the cable adjuster (different from the stop screw) on the throttle body to syn the system you are making a mistake 'cause it may create the problem you have.

To do it proper once it is out of syn because of the above, you have to re-zero the throttle plates/butterfly's against the stops. Its the only way I know to get the start lever to open both throttles the same amount. This requires a good digital meter to set the TPS which is done with the adjustment(throttle stop) screw on the left throttle body.. This is called "zeroing the TPS. "After this is done the syn is completed using very small adjustments to the right throttle body stop screw(and/or the "big brass screw") It should require a very small adjustment.(Once zeroed do not mess with the left stop screw!!!)

Once this is done the start lever is adjusted at the handlebar to get the proper movement of BOTH throttle bodies together.

Its not hard to do and will take an hour or so your first time. The good news is once done it will remain in syn for a long time.

Ball park... the low position on the start lever 1100/1300 rpm high position will add 200/300 more rpm than the low. When warmed up both of these rpm numbers will be higher.

You can search this forum for zero procedure in step by step. If you can't do it yourself seek someone that knows oil heads or a dealer service department (BMW).

mike :-)

[Riverside]

I took the bike back to the shop that synced the TBs and explained the problem, showed him the difference in the throttle wheel movement when pulling on the cold start lever. He hooked it back up to the mamometer and made a few adjustments and the problem has gone away. I am not sure what was adjusted but the right side wheel is still not moving as much when pulling the cold start lever, but, the rough idle and cold start problem has been eliminated. I will be due for an 18000 mile service in the next month or two depending on how much riding I can get in, so I'll have the dealer check out the TPS at that time. Clymer manual advises for R1150 models that TB sync be done using MoDiTec unit... whatever that is I'm sure I don't have one. I was planning to build a mamometer until I read that. In the meantime the bike is running much better and does not make unusual noises anymore. I'm going to err on the side of caution and not make any adjustments till I actually understand what I am doing. Thanks for the input everyone.

[kirby]

That's good. They don't have to be EXACT but when is not moving and the other is..not good.

Don't need the Bmw stuff to do a syn, its easy using an electronic syn device or manometer which both can ber purchased from places like the motorcycle super store or chaparral. $110 +-.