1150GS Starting problems

[nock]

Hi guys,

I had a problem starting the tractor this morning. The starter motor was turning, but didn't seem to be engaging with the engine so just kept turning & turning (there appeared to be plenty of juice).

Now I've had it connected to an optimate and that indicates all is well with the battery. I replaced the HT leads, coil and plugs not so long ago and its been running really well until this morning. I could definitely smell petrol and the usual whirring came on after the ignition was turned, suggesting the fuel system was priming and working OK.

I haven't ridden it since Tuesday last week, and in the mean time I've changed the indicators for smaller items with smaller bulbs that have a greater intensity (but are rated exactly the same as the stock items - from memory 12v 20w? although they do seem to run hot). They worked fine after I'd fitted them and the engine ran. I don't think the problems stem from the new indicators but I could be wrong.

I'm thinking that its probably the solenoid that throws the starter forward to engage the engine, or the starter itself. Anyone heard of this before, or got any suggestions?

Thanks

 

[nock]

I had a similar problem with a Landrover before and it was caused by the starter drive cogs path being blocked by the flywheel as it was thrown forward. Easily remedied by putting the landrover in gear and rolling it forward to move the flywheel a tad and clearing the starter drive cogs path. It was however an early indication that the starter was on its way out.

 

[ChrisH Kerry]

I thought with these pre-engaged type starters that the motor doesn't turn until the solenoid has engaged the cog in the flywheel... maybe solenoid is stuck?

 

[MattW]

The bendix might be all gunged up and not throwing into engagement with the flywheel. I'd whip the starter off (2 minute job) and give it a clean / fettle (aerosol brake cleaner is good for this).

Don't be tempted to grease the bendix assembly - it just attracts more dust - I used moly dry-slide stuff.

 

[darrenptalbot]

The bendix might be all gunged up and not throwing into engagement with the flywheel. I'd whip the starter off (2 minute job) and give it a clean / fettle (aerosol brake cleaner is good for this).

Don't be tempted to grease the bendix assembly - it just attracts more dust - I used moly dry-slide stuff.

Bendix?

 

[MattW]

Bendix?

The gear assembly that throws forward to engage with the flywheel ring gear

The image above borrowed from MikeP's starter strip thread:
http://www.ukgser.com/forums/showthread.php?t=207984

Although don't let the thread above frighten you - you won't need to get into the brushes / magnets etc.

 

[darrenptalbot]

 

[dancata]

+1 on the above. Clean it and put it back in.

Dan.

 

[steve'o]

Check the solid lump inside the solenoid is moving freely. Mine was all gunged up and only just moved. Cleaned it and no problems since.

 

[warmshed]

The gear assembly that throws forward to engage with the flywheel ring gear

The image above borrowed from MikeP's starter strip thread:
http://www.ukgser.com/forums/showthread.php?t=207984

Although don't let the thread above frighten you - you won't need to get into the brushes / magnets etc.

They don't use a bendix they use a solenoid to engage the starter gear before starting to turn the starter motor. A bendix is used when the starter motor turning throws the gear into the flywheel cogs, which is bevelled to accept it, not a good engineering practice. (This is only found on old pre 70 vehicles normally). If yours is turning without the gear engaged it is probably due to the solenoid contacts being fused together, this is often the result of trying to start it with a low battery. Take the solenoid apart and clean (or separate ) the contacts.

 

[MattW]

They don't use a bendix they use a solenoid to engage the starter gear before starting to turn the starter motor. A bendix is used when the starter motor turning throws the gear into the flywheel cogs, which is bevelled to accept it, not a good engineering practice. (This is only found on old pre 70 vehicles normally). If yours is turning without the gear engaged it is probably due to the solenoid contacts being fused together, this is often the result of trying to start it with a low battery. Take the solenoid apart and clean (or separate ) the contacts.

Fair enough - terminology error on my part.

Still worth taking it to bits and cleaning the gear and solenoid actuator.

 

[nock]

Right - I must first thank you all for your suggestions, but also apologise for leading you up the garden path.

In my defence I was trying to diagnose a problem in the pitch black at 5am in the freezing snow, with my sleepy head on!

In daylight and fully awake I can tell you that the starter motor DOES engage the engine, the plugs are sparking (all be it a yellow rather than blue spark), and the plugs are wet with fuel.

I've put a new BMW battery on (how much?) as the ABS lights were intermittently showing a fault over the past few months suggesting to me the battery was on its way out, but the symptoms remain the same.

I have taken the starter motor off and am in the process of dismantling and cleaning it.

The guy at Vines said not to worry about the yellow spark "if there's a spark at all, they usually start", but "if the starter doesn't get the motor turning fast enough it won't catch".

If the strip and rebuild of the starter doesn't work then I'm struggling - could it be a bad earth somewhere or some other electrical issue?

 

[DrFarkoff]

Right - I must first thank you all for your suggestions, but also apologise for leading you up the garden path.

In my defence I was trying to diagnose a problem in the pitch black at 5am in the freezing snow, with my sleepy head on!

This is a common thing and what my dear friend Ogmios has coined "Hard of Thinking!"

In daylight and fully awake I can tell you that the starter motor DOES engage the engine, the plugs are sparking (all be it a yellow rather than blue spark), and the plugs are wet with fuel.

Change Plugs!

The guy at Vines said not to worry about the yellow spark "if there's a spark at all, they usually start"

As they say in the Surveys STRONGLY DISAGREE

Change the plugs they're a helluva lot cheaper than the hall effect sensors which you will be exposing to excessive current load by grinding away at the motor!

 

[nock]

Having now spoken to the organ grinder (not the monkey as quoted earlier) at Vines, the most likely cause of these symptoms is the Hall Effect Sensor, which has broken down and is now sending a weak and incorrectly timed spark to the plugs.

This diagnosis seems to tick the boxes as far as I can tell so I've just ordered a warranteed 2nd hand one from Motoworks (£85). If it doesn't work they'll take it back and refund the money

 

[MattW]

Having now spoken to the organ grinder (not the monkey as quoted earlier) at Vines, the most likely cause of these symptoms is the Hall Effect Sensor, which has broken down and is now sending a weak and incorrectly timed spark to the plugs.

This diagnosis seems to tick the boxes as far as I can tell so I've just ordered a warranteed 2nd hand one from Motoworks (£85). If it doesn't work they'll take it back and refund the money

Makes sense.

Not hard to fit - worth changing your alternator belt at the same time (as it has to come off anyway). If you have a search, there's loads on here about changing (and re-timing) the sensor plate

 

[warmshed]

http://users.rcn.com/dehager/service/oilhead_hall_sensors.pdf


might help.

 

[MattW]

A tip Steptoe gave me for loosening the crankshaft pulley bolt is to firmly hold a spanner on the bolt and tap the starter button (obviously don't lock the flywheel as in the Merkin instructions). Cracks the nut loose really easily

I scribed the position of my old sensor plate and fitted the new one in the same position. You can check the timing by switching the ignition on, turning the engine over with a spanner on the crankshaft nut and listening for the fuel pump priming as the timing marks line up. Mine didn't need adjusting as it was spot on using the scribed position.

 

[Steptoe]

A tip Steptoe gave me for loosening the crankshaft pulley bolt is to firmly hold a spanner on the bolt and tap the starter button (obviously don't lock the flywheel as in the Merkin instructions). Cracks the nut loose really easily

.

Blimey, i've just spent 5 minutes giving the same advice on the "replacing hall effect sensor" thread - Copied below

Try this diagnosing and replacing, hope you never need to though.

http://users.rcn.com/dehager/service/oilhead_hall_sensors.pdf

I'd be very careful taking any notice of that american advice. - some of the diagnoses info is wrong and could lead you on a wild goose chase, and other info that will leave you fecked by the side of the road

i.e. one simple instance - the socket needed to undo the pulley nut is a 16mm.
And there's a very simple way if you want to undo the pulley nut by yourself, not the crap way in the article .

Place the 16mm socket/spanner on the bolt, turn the ignition on and with one hand holding the spanner/socket wrench, with the other hand give a quick tap the starter button = result - nut cracked undone. -

 

[DrFarkoff]

See before you go pulling things apart try a set of plugs

PLEASE!

 

[oldnfat]

See before you go pulling things apart try a set of plugs

PLEASE!

+1 on the plugs....had a similar situation....start with the cheap and easy first.