Hard to start

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Bigtony
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Hard to start

Postby Bigtony » Sun Jul 08, 2018 3:42 pm

Hi guys I have aquired a 2003 r1100s when I got it it wouldn’t start after changing the starter motor due to common fault I believe plate inside destroyed the armature fitting a new battery and fuel pump plate as wiring to fuel pump was faulty also replaced the hes if I squirt starting fluid she fires up and runs ticks over fine drove it up and down the road didn’t miss a beat leave it for half hour and it won’t start unles I give it a squirt any ideas guys thanks

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Galactic Greyhound
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Re: Hard to start

Postby Galactic Greyhound » Sun Jul 08, 2018 4:21 pm

From your post, you appear to be saying that the engine will not fire up until Starting Fluid is used and, once fired up by this method, the engine runs and idles with no problems until switched off and left to cool down at which point it will not fire up unless the Starting Fluid is used again.

This being the case, the problem would appear to be incorrect air/fuel mixture on starting.

A common fault when working on the Oilhead bikes is for the Throttle Cables to get pulled out of their cable adjuster ferrules which are situated at the top of the Throttle Bodies (TBs).
This fault opens the Throttle Butterfly in the TB which results in too much air being mixed with the fuel causing poor starting (weak mixture).

Check that your Throttle Cables are FULLY seated in these adjuster ferrules on EACH TB and that, when the Throttle is FULLY closed with the Choke OFF, the Stop Tab on each TB pulley is contacting the TB Pulley (Butterfly) Stop Screw (this is factory paint-locked and must NEVER be adjusted).
You will need to lie down and look up at the underside of the TBs to check this Stop Screw contact and a distinct 'click' should be heard if the Throttle is released quickly and the tab on the pulley strikes the Stop Screw.

Also check that the Rubber Cap is fitted to the Vacuum Take-Off Tube at the bottom of each TB.
These can perish and fall off so weakening the mixture.

Here is a useful forum link (Oilheads Q&A/Tech Articles) for your Oilhead:
'Oilhead Not Starting/Running'
viewtopic.php?f=69&t=21616

Report back as to how you get on! :smile:
Ced.

R1100RT 1996.
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Re: Hard to start

Postby Bigtony » Sun Jul 08, 2018 8:52 pm

Hi Galatic greyhound
I have checked both throttle stops both are hard up to the stops both cables are in their respective ferrules the choke lever that I see only opens the throttle as when I activate the lever the throttle twist turns I can’t see any way that it acts as a choke am I wrong

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Galactic Greyhound
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Re: Hard to start

Postby Galactic Greyhound » Sun Jul 08, 2018 10:04 pm

Hi Bigtony,

The 'Choke' lever is NOT a choke like in carburetted bikes.

On your R1100S Oilhead, when the 'Choke' lever is operated it causes both the Throttle Body (TB) Pulleys to rotate a small amount.
As the Throttle Butterflies are connected to the TB Pulley shafts, this causes both the TB butterflies to open a little.
The LH TB shaft is also connected to the Throttle Position Sensor (TPS) which is a black rectangular box on the side of the TB.
The TPS signals (a varying resistance) to the ECU (Motronic) the position of the Throttle Grip so that the ECU knows how much fuel to inject for a given Throttle position.
On a cold start, the 'Choke' should be ON fully - this sets the TPS and the TB Throttle Butterflies to the Starting position.
The ECU checks the Oil Temp sensor at Ignition On and, if the engine is cold, sets the fuelling injection to be 'Rich'.
When the Choke lever is set to 'ON' it can usually be operated a little further by hand - this sets a richer mixture for cold winter starting - the lever will fall back to the normal ON 'Rich' position when it is released.
DO NOT OPEN THE THROTTLE GRIP BY HAND WHEN STARTING - KEEP THE THROTTLE CLOSED - Let the Choke lever determine the TB Butterfly openings or you will upset the start-up fuelling!

When the engine starts, ride the bike immediately (do NOT leave idling) and keep the Choke ON until the engine is warmed up (usually at 2 bars on the RID Oil Temp Gauge if you have an RID fitted).
When the engine is warmed up the Choke can be switched OFF and the engine should idle without stalling.

When the bike is fully warmed up (5 bars on the RID Oil Temp Gauge), the throttle control of the engine should be smooth without any surging/jerking over the whole throttle range.

On the later Oilheads (post 1996) like your R1100S, the throttle and choke cables are a 4-cable system connected into a Bowden Box which sits under the Battery Tray.


If your Throttle Cables are seated correctly and the rubber caps are not missing from the TB Vacuum Tube take-offs, then probably the next thing to do re your starting problem is to perform a Throttle Balance to ensure that the TBs are set correctly.
You can do this with a home-made Manometer or Vacuum Gauges:
DIY Manometer: https://www.youtube.com/watch?v=0nKaGEMLZjs

Here is one of the many YouTube videos on 'Oilhead Throttle Balancing':
R1100 Throttle Balancing: https://www.youtube.com/watch?v=CP_8LOv2Kws
Look for the Chris Harris videos on YouTube which cover many of the Oilhead maintenance aspects.

For working on your bike it is better to have a Haynes or a Clymer manual to guide you and either of these manuals will save their purchase cost time and time again.
Ced.

R1100RT 1996.
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Re: Hard to start

Postby Bigtony » Mon Jul 09, 2018 6:31 am

Thanks for you very detailed explanation I have been a car mechanic since I was a lad many moons ago but motorcycles are a different ball game I’m going to get a Haynes manual you wouldn’t believe how many of these manuals I have in my collection
I will report back after more investigation thanks

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Re: Hard to start

Postby windmill john » Mon Jul 09, 2018 8:04 am

Get a Clymer manual as well if you can afford it!
It’s good to have both, but Clymer goes into more detail where Haynes sometimes says take it to a dealer.
I don’t want to upset one of my bikes as there is only a Haynes manual available, but if you haven’t bought either yet, go for the Clymer.
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Re: Hard to start

Postby Galactic Greyhound » Mon Jul 09, 2018 9:48 am

Just a thought here on the initial not firing up:

When the Ignition is first switched On and the Starter Button pressed, the engine cranks over fairly slowly and the Starter Motor puts a very high load across the Battery causing its voltage to fall.

The Battery voltage can fall as low as 9 volts normally when cranking over the engine.
If the voltage falls BELOW 9 volts due to an old or low battery, the spark at the plugs will be much reduced and may not fire the fuel mixture under compression.

You can check if this is the case by connecting a Voltmeter directly across the Battery terminals and cranking over the engine.

You might also try jumpering a good car battery across the bike battery (car engine NOT running).
If the engine then fires up OK, then the problem is likely an aged, faulty or discharged bike battery.
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

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Re: Hard to start

Postby Bigtony » Mon Jul 09, 2018 12:44 pm

Hi galactic greyhound
I’ve just fitted a brand new agm 95ah battery and a brand new starter motor but it does seem to crank slowly

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Re: Hard to start

Postby Galactic Greyhound » Mon Jul 09, 2018 2:00 pm

95Ah !!!

That's a big battery I am surprised it fits on the bike!

If you meant a 9.5Ah battery then this is too small a battery and will struggle to turn over or even fire up an Oilhead.

The correct size battery is 12v 19Ah and I would not fit anything less than that if you want it to turn over in the winter.

I used the Exide Gel 12v 19Ah batteries in the past which last about 4 years.
I am now running a MotoBatt 12v 20Ah AGM battery which seems to be doing OK.

If you have ABS, then the ABS dash lights will show ABS Fail (flashing alternately) on starting if the battery is struggling.
Ced.

R1100RT 1996.
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Re: Hard to start

Postby Bigtony » Mon Jul 09, 2018 5:33 pm

Sorry my mistake 19ah econoline from tayna batteries

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Galactic Greyhound
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Re: Hard to start

Postby Galactic Greyhound » Mon Jul 09, 2018 6:51 pm

Aah! :smile:

Tayna batteries are good - I bought a battery off them for my neighbour's lawn tractor - still going strong.

I am surprised that the engine is only turning over slowly in this hot weather.

This may be caused by a faulty battery, a faulty starter motor or corroded battery connections.

I think you should put a voltmeter across the battery terminals and read the voltage when the engine is being cranked over - it should not be less than 9.0 volts DC.
If it is, then there is a problem.

If there is a problem, jumper a car battery across the bike battery (car engine NOT started) and see if things are any better.
If so, then the battery is suspect.
Even new batteries can be faulty!

Warranty: https://www.tayna.co.uk/tutorials/batte ... nformation
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
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Re: Hard to start

Postby Bigtony » Tue Jul 10, 2018 7:37 am

I’ve jumped it from a booster pack it turns over marginally quicker but I have to have the throttle open fully and clutch pulled in then it fires up possibly weak fuel pump unable to check pressure as I don’t have a tester for that or fuel regulator faulty

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Re: Hard to start

Postby Galactic Greyhound » Tue Jul 10, 2018 9:32 am

Something is not right, it should start easily with the throttle closed and the Choke On.

If the battery is faulty and the voltage drops too low on starting then this will affect the fuel pump operation as well.
Connect a voltmeter across the battery terminals and measure the voltage when the engine is being cranked over - it must remain above 9.0 volts DC.

If you suspect fuel pump problems then see this link:
viewtopic.php?f=69&t=21616

Go to Section '2. ENGINE CRANKS OVER BUT WILL NOT FIRE' and read the sub-section 'Fuel Flow Check'.
You are looking for a flow rate of 2 litres/minute from the Fuel Return hose from the Regulator back to the Fuel Tank.
It is best checked if you run the fuel pump alone continuously for one minute but it can be done pro-rata for say 15 seconds using the Starter Motor (this will flatten the battery).

Note that the link is for an R1100RT Oilhead so some things might be different for your bike but the principle and return flow rate is the same.

Be alert to the possibility of a split rubber internal fuel hose (usually the 'U' hose) inside the tank which will reduce the fuel pump pressure. This will show up under the flow rate test.

The fuel pump pressure is around 45 psi and the regulated pressure on the injector rails is around 34 psi.
There is little or no pressure on the fuel Return Hose.

If the bike is running fine under load and idling OK when you get it started I can't see that there are fuelling problems.
Ced.

R1100RT 1996.
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Re: Hard to start

Postby sykospain » Tue Jul 10, 2018 10:25 am

Ced:- I'm guessing that a year'03 1100S has stick coils interposed between each ignition lead to the cylinder heads and the ( upper ) spark plugs. It might even be a 4-plug motor.

IF so, those coils trapped inside the extremely hot and narrow cylinder head tubes eventually rot due to temp variations and condensation, causing starting / running problems.

Just a thought.

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Re: Hard to start

Postby Galactic Greyhound » Tue Jul 10, 2018 12:07 pm

Hi Al,

Thanks for that!

I had thought that all R1100 series were single plugged but after reading your post found that this was not the case.
The R1100S built after 2003 has a dual ignition system - whether this is dual plugs or plugs and stick coils like the R1150 series I'm not sure, I think likely the latter.

R1100S: https://en.m.wikipedia.org/wiki/BMW_R1100S

I think Bigtony needs to tell us if his 2003 R1100S is twin plugged or not and if dual-plugs or plugs + stick coils are used!
Ced.

R1100RT 1996.
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Re: Hard to start

Postby Bigtony » Tue Jul 10, 2018 6:01 pm

This one is single plugs with stick coils

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Re: Hard to start

Postby Galactic Greyhound » Tue Jul 10, 2018 7:17 pm

Hey! Al was right! :smile:

Stick coils give more problems than the older ignition coil system.

Remove both stick coils, give them and the plugs a clean and check if they are both sparking when the engine is being cranked over.
Although they both appear to be firing when you get the bike started, there may be a problem with one of them not sparking during cranking due to the lowered starting voltage.

What is the voltage across the battery during cranking?
Ced.

R1100RT 1996.
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Re: Hard to start

Postby Bigtony » Wed Jul 11, 2018 9:20 am

Going to check that tonight along with fuel pump pressure both plugs were sparking when cranking

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Re: Hard to start

Postby DrewR1100S » Wed Jul 11, 2018 9:51 am

Hi Bigtony, I have a 2003 R1100S it is a 'twinspark' motor (stick coils for main plugs and conventional coil for secondary plugs) Have you carried out ecu reset after re-connecting the battery? Turn on ignition and fully open and close throttle a couple of times, then press starter.
Drew

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Re: Hard to start

Postby Bigtony » Wed Jul 11, 2018 10:25 am

Yes I have done the reset doesn’t seem to make a difference

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Re: Hard to start

Postby Galactic Greyhound » Wed Jul 11, 2018 11:23 am

Yes I have done the reset doesn’t seem to make a difference

Drew might have hit on a possible cause of poor starting as any Throttle 'learned' values will likely have been lost during the battery replacement.

I think that your 2003 R1100S is fitted with the MA2.4 ECU which has the 'learning' capability'.

However, with the MA2.4 ECU (Motronic) Throttle Relearn procedure you need to ensure that the existing 'learned' values have been deleted from the ECU memory before doing a Throttle Relearn.

Learned Values Memory deletion occurs after the battery is disconnected from the ECU for 10 minutes or more.
However, unless a Throttle Relearn was done immediately after replacing the battery, your starting attempts may have caused the ECU to learn new false Throttle values.

To relearn the Throttle max/min positions, carry out the following procedure:

1. Disconnect the battery earth connection for at least 10 minutes.

2. Reconnect the battery earth connection.

3. Switch the Ignition ON.

4. Operate the Throttle from minimum to maximum position twice in succession.

5. Switch the Ignition OFF.

6. The Throttle Relearn procedure is complete.
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
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Re: Hard to start

Postby Bigtony » Wed Jul 11, 2018 1:25 pm

Ahh that’s what I didn’t do was switch ignition off after the reset I just went on to crank it over will try that also

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Re: Hard to start

Postby Bigtony » Thu Jul 12, 2018 5:01 pm

Hi guys checked voltage drop across battery when cranking and it 10.98-11 volts so all good there just disconnected battery to reset the module and going to check fuel pressure

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Re: Hard to start

Postby Bigtony » Thu Jul 12, 2018 5:41 pm

Just reset and it started a bit quicker but still needed a bit of throttle?

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Re: Hard to start

Postby Galactic Greyhound » Thu Jul 12, 2018 8:09 pm

The voltage of 10.98 - 11.00 volts across the battery when cranking is very good so there does not appear to be any problems with the battery voltage collapsing on starting.

It should not really need any throttle to start if the Choke is used when cold although sometimes this might be necessary to 'catch' the motor when it fires up.

I take it that it is now starting on the button without the use of starting fluid?
If so, I would suggest taking the bike for a decent long ride of around 50 - 100 miles to see how it behaves and to clean out the cylinders - pay attention to the smoothness of the motor at all throttle positions, if there is any surging or jerkiness and if it idles OK.
This will get everything nice and warm and also allow the ECU to learn and rebuild the 'Offsets' Table which you have cleared except for resetting the Throttle positions.

I suspect that your bike is fitted with a Cat and Exhaust (Lambda) Sensor so this will come into effect when warm on the ride and new Offsets for this will be built up.

Let us know how it goes!
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!


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