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1000SP slow cranking... Bosch starter

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Jalfrezi View Drop Down
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    Posted: 21 Nov 2018 at 08:52
Hi,

I've always found the starter on my bike sluggish, starting is always a worry although to date it's not been an issue.  It just seems like I'm right on the edge, and I'm quite sure as it get's colder this will become more of an issue.  Lately, opening the throttle, or applying choke seems to put too much load on the starter, and it grinds to a halt.

The battery seems good, and I load tested it with my multimeter, so I'm looking at the starter motor.  It's a Bosch, and was rebuilt by the previous owner in the last couple of years.  However, I have read descriptions that suggest that the Valeo starters put less load on the battery and spin faster, so I'm thinking this could be a good next step.  Is this a good "upgrade" over the Bosch?  Is it a straight swap?

Thanks
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Brian UK View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 21 Nov 2018 at 09:17
The Valeo starters have permanent magnets and gearing, so yes, they take less out of the battery and spin better. But some of the early models had problems with the magnets becoming dislodged so beware of buying an old second hand one.
There is a later bosch unit which is similar, fitted to the later CARC bikes.  Can't guarantee it's exactly the same fitting though.

Have you checked all the wiring connections to make sure they are clean and tight, and also the contacts in the solenoid might not be so good. These are replaceable.

How did you load test the battery? The only way is to check the voltage when the starter is spinning.
Brian.

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johnno View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote johnno Quote  Post ReplyReply Direct Link To This Post Posted: 21 Nov 2018 at 11:45
sorry  i cant help with the answer fully but i do remember having this problem with my T5 and it was something to do with the connections but b4 i sorted it i turned the motor over a few times before flicking kill switch on . I also held clutch in and it used to work fine . Ithink it turned out to be a earth problem

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Post Options Post Options   Thanks (1) Thanks(1)   Quote Ken-Guzzibear Quote  Post ReplyReply Direct Link To This Post Posted: 21 Nov 2018 at 12:22
Mate I have a 1000 G5 same engine I tried the Valeo, here are the differences from my findings:-

The carb engine often needs to spin over longer than a FI one, spin the valeo more than 20-30 secs they do not like it
The Bosch is able to churn over a cold engine longer
You have slow reluctant starter look at all your connections BUT this smacks of battery knackered, if when you do get going the top end is sluggish or the occasional missfire suspect the battery Just because it is a newish battery does not mean it is ok under load. 

Well worth modifying the start cct ...easy on the older bikes a relay from pyro dan add a relay base for same rewire it then carry a spare relay quick and easy swap 

The Bosch starters are extremely reliable, Merc use them in most of their vee hi kkuls (lol) over 30 yrs and 260k miles had mine refurbished only twice last time 4 yrs ago when bike was rewired by Towza

so my advice, for what it is worth, keep the Bosch starter
Check the wiring for corrosion and connections look at battery main earth to batt box/frame seen one that had broken at the battery box tag. make sure the earth is connected via a battery tag that bolts thro to the gearbox and it is clean, look for black marks indicating flashing. check wee tag to starter solenoid make sure battery disconnected before going in there as a flash to earth will fire 'er up

Do the "Click no start modification" 

If the starter is still sluggish easy check boost it from another vee hikk le ...if it then spins up Robert is your Fathers Brother ..... As Johnno points out pull in clutch before starting 'er up, this has to be done on most of the FI bikes, oh and the V1000 convert. as the clutch has a cut out ....
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Gianni Quote  Post ReplyReply Direct Link To This Post Posted: 21 Nov 2018 at 16:12
Had the same symptoms on my LMV recently - started while I was away touring so had to keep using a dodgy starter. Got back and checked battery voltage, wiring, etc. The voltage was dropping to 10.6v and below when firing it up. Swapped the solenoid with a known good spare, same problem. Swapped the whole starter motor with one from the T3 and all cushty so pointed to the starter motor.
 
Put the dodgy starter on the T3 and it worked albeit a little sluggishly - so I guess the extra compression and capacity might have just pushed an already weak motor over the edge?
 
Whisked the starter off to a local Bosch specialist who diagnosed a soldered internal connection on the main motor winding that had overheated and semi-melted. I gave him money and waited a day. He gave me a working starter.
 
IIRC the Valeos have an internal reduction mechanism so spin the engine slower for higher starter revs - drawing less current and loading the starter less. I have one on my LM1 and it works fine.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote theone&onlymin Quote  Post ReplyReply Direct Link To This Post Posted: 21 Nov 2018 at 17:42
I've a G5, bosch starter (reconditioned 2 years ago by https://www.google.co.uk/search?q=unistart+london+alternators&oq=unistart++london+alternators&aqs=chrome..69i57.27165j1j4&client=ms-android-orange-gb&sourceid=chrome-mobile&ie=UTF-8 ) , 3 year old battery, lego switchgear. Started up 1st kick without any spinning in 5C peeing wet yesterday. Lives outside 365 days a year.
If the battery runs down a bit a nail across the solenoid starts it 1st kick as well so it does. I throw a new starter relay at it once a year. Maybe it's become a low compression engine over the years. 

Cheers
Min

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Jalfrezi Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 2018 at 10:54
Originally posted by Brian UK Brian UK wrote:

Have you checked all the wiring connections to make sure they are clean and tight, and also the contacts in the solenoid might not be so good. These are replaceable.


I removed the main connectors to the starter, cleaned up (were filthy), and refitted nice and tight.  I also cleaned the earth strap from the battery, and the connection on the engine.  Anywhere else that's important?

Originally posted by Brian UK Brian UK wrote:

How did you load test the battery? The only way is to check the voltage when the starter is spinning.


Cranked it over with a DMM on the battery for around 5 seconds, slight fluctuation in the readings, but 9.67v was the lowest I saw.  I think that's within serviceable limits, but not sure TBH.  Happy to replace if that is too low.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote jefrs Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 2018 at 10:54
A slow starter motor, especially in colder weather, is often just down to an old battery. A good battery should show at least 12.6VDC on the voltmeter 24 hours after charging. For an older battery 12.5V may be acceptable but 12.4V means new battery time - this is at 24 hours after being fully charged, without use, and means the battery is not holding charge. 
But this is not the whole story. As batteries age they lose charge capacity and their cold cranking amps (CCA) will go down too. The latter is what they need to churn the starter; if the battery doesn't have enough amps in it the volts drop until Ohm's Law is satisfied - the starter motor turns slowly. The CCA (in amps) is approx 15-20 times the charge capacity,  for example a 12Ah battery should be able to deliver up to 240 Amps. If a starter motor is 1.5kW (2hp) then it needs 12V at 125A to spin it, and it will draw more on start-up. 
The battery voltage should not be dropping to 10.6V unless the motor is drawing too much current (a fault), or the battery is dead.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Mike H Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 2018 at 20:35
Originally posted by Jalfrezi Jalfrezi wrote:

I removed the main connectors to the starter, cleaned up (were filthy), and refitted nice and tight.  I also cleaned the earth strap from the battery, and the connection on the engine.  Anywhere else that's important?


When I did my last rebuild I moved the battery earth (a new one BTW) to one of the Allen bolts on back of the gearbox, normally it's on a bracket on the frame that also holds one corner of the battery tray IIRC, and can get quite manky. I figured that, from there, it would be easiest and most reliable path to starter motor body.

I have also just remembered finding this frame bolt was loose on the 850. Shocked Starter still worked tho.





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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 2018 at 22:04
Digital meters are not so good for reading quick variations in voltage, unless it's an expensive one. They average over a short period.

9.6v seems a bit low to me. Do you have access to another bigger battery you could connect in parallel with jump leads? I have used a heavy duty charger to boost starting voltage. Even charging the battery up with a charger then immediately trying to start. All this is to see if higher battery volts help the starter, so we can tell if it's the battery or starter.

The other factor, what oil is in the engine? 20W50 can get quite heavy in cold times and a 10W40 will help it spin faster. My car uses a 0W30 for that reason.
I had a Bosch starter on my Spada III (must have been changed as valeo was OEM) and that was fairly slow too. I used 10W40 in that.

Is it a standard 30AH battery or one of the later type small capacity AGM ones? And how old? As said above, all batteries lose capacity over time.

Jst trying to save you spending money on a starter then finding it is still slow because the battery is on its last legs. If the Bosch was overhauled 2 years ago, I would tend to assume it wasn't too bad.


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Post Options Post Options   Thanks (0) Thanks(0)   Quote Jalfrezi Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 2018 at 22:12
I have a spare car battery here, so will hook it up with jump leads, and see if that helps.

20W50 in the engine, as had been recommended (somewhere), I did wonder if 10W40 would make a worthwhile improvement in the winter months.  Not long until the next oil change, so I could give that a try.

The battery is a standard lead/acid type (Banner I think).  30AH, and approx 18 months old.

Thanks for you help.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 23 Nov 2018 at 07:50
Well at 18 months, the battery ought to be good.

Of course, when you are told the starter was "rebuilt" presumably because it wasn't working at all well, you don't actually know what was done.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote iceni Quote  Post ReplyReply Direct Link To This Post Posted: 23 Nov 2018 at 08:33
Just removed a Valeo starter motor from one of my bikes. 2 of the four magnets dislodged. Spare parts seemingly unavailable. Bummer
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Jalfrezi Quote  Post ReplyReply Direct Link To This Post Posted: 23 Nov 2018 at 08:43
Originally posted by Brian UK Brian UK wrote:

Of course, when you are told the starter was "rebuilt" presumably because it wasn't working at all well, you don't actually know what was done.

Indeed, I think a starter motor strip down is on the horizon.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 23 Nov 2018 at 09:59
Originally posted by iceni iceni wrote:

Just removed a Valeo starter motor from one of my bikes. 2 of the four magnets dislodged. Spare parts seemingly unavailable. Bummer

Where have you looked? I'm sure there was one place selling bits for those. You could get a new case complate with magnets.

Had you thought of araldite? I managed to glue a magnet into a motor body once, from a washing machine actually. It worked fine until eventually another part failed.
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