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-   -   starting problems/disk break upgrade (https://www.horizonsunlimited.com/hubb/bmw-tech/starting-problems-disk-break-upgrade-7825)

andreasb 9 Nov 2002 13:29

starting problems/disk break upgrade
 
When the outside temperature drops below 65degrees F my bike (R80GS/1992) does not start up easily.... I have to use the choke and turn the starter for at least 5-10 seconds before it kicks in....sometimes one cylinder at a time...
Recently I had a lot of work done on the bike (a Greek mechanic using a Greek 'torque wrench' had over tightened one of the rockers and eventually the bolt holding the cylinder ripped right out of the crank case/engine block).... it took a lot of patience and three days to fix (threads recut, piece of metal welded to end of bolt and threads recut as well, refitted) and at that time I changed all the oils, replaced or cleaned filters (except for the K&N reusable air filter...only knocked out most of the accumulated dirt)etc.
Also had the carbs balanced, spark plugs replaced but still no improvement...wonder if the starting difficulties could be electrical? Too weak of a spark...(spark looks ok).... and if yes, what can I do to check it (do have a voltmeter)
And to make things even more 'complicated' I have noticed that the plugs end up looking rusty red brown even after hours of riding at medium rpm (4000)...fuel consumption is good though at around 5.5 liters/100km....
Once the bike has warmed up it runs smoothly and without any problems...it is starting the bike cold that is difficult.

On a different note...my floating front disk break started to make terrible noises and I head the rivets slightly tightened (but still loose) to get rid of it...now they are screeching at times...and I am thinking about 'upgrading the disk breaking system' completely... since the breaking power is pretty poor with loads of weight.
Does anybody have a suggestion on how to get more breaking power and at the same time NOT spent an arm and a leg...was quoted $1000 for a new, dual disk breaking system...but there must be options, right? Unfortunately, the disk might have to go....
Andreas

JohnZ 20 Nov 2002 21:35

It's always best to start with the most obvious answer - your battery. The power needed to turn the BMW boxer engine is high, and any weakness in the battery will show here, at start up, as the oil has turned cold and aids drag on the engine, starter and as such, the battery.Old batteries do not like the cold, either! Try starting with the clutch lever pulled in - this lightens the load on the battery, too. If you can, I'd swap the battery ( maybe borrow oné just to check ? ) and see if this cures it. A good shop should check the battery for little or no money, too. You must have a strong, healthy battery before you go on to other things here!
Are the discs worn out? If so, a new ( aftermarket ) disc should do you. These are quite cheap in Britain, but I don't know if there is market for them in the U.S. There are other brake kits available, but they are very, very expensive and usually marketed at top range sportsbikes.
Hope things work out.

Timo 20 Nov 2002 22:25

Your starting problem (obviously) could be a range of things, but for the sake of clarity: Is it that the bike is taking longer to 'fire' or is it that the starter is slower, or laboring? Often a lean setting on the carbs will result in difficult starting. Look to what was changed in the recent service for the solution.

As to your braking problem: Disks do wear out an as they get thinner and as the metal fatiques the whole disk can warp and start to make all kinds of strange noises (and grab/ pulse!). MAP engineering (http://www.map-engineering.com/brakes.htm) makes larger diameter disks that are reproted to be quite good - Grant recently installed one on his G/S along with a PM 6 piston caliper. You can read about it in his bike description - Last I asked he was very happy. Others have opted for the ($400 USD) disk and stock caliper and report much improved braking. Given the cost of even cheap replacement disks, this is a relatively economical option for the improvement. The stock GS brakes are definitly on the small side. Upgrading now when you have to replace parts anyway is advised.


Sean Kelly 23 Nov 2002 19:11

Hi Andreas

Where and how the devil are you???? We're in Varanasi heading Kathmandu.

Our plugs go rusty red too, so must be something to do with the fuel over here????

Also, lost one alternator rotor - now there's a suprise. We were of course carrying a spare and extractor tool! Need another spare one now in case mine goes.

Cheers




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Sean

Grant Johnson 24 Nov 2002 02:34

If it's not electrical - in other words the battery is excellent:

For how long has it been hard to start? Since what was changed?

Possibility:

This sounds like a problem with the choke circuit. Either it's clogged, or the gasket is leaking (the screws holding the choke assembly - it's actually an enrichment circuit - typically loosen slightly and the thin paper gasket is sucked in and leaks air - the opposite of what you want.)

Also if it's been a problem since the carbs were last apart, the "choke" assemblies could have been reversed. Common mistake, and then they won't work at all, so you're always starting without the choke.

------------------
Grant Johnson

Seek, and ye shall find.

------------------------

One world, Two wheels.
www.HorizonsUnlimited.com

paulc 25 Nov 2002 18:48

I had the same problem with the stud pulling out of the crankcase. It is a common problem with the top front studs. There is a tiny oilway where the stud screws into the crankcase that is very easy to miss, Make sure your repair has not blocked this oilway or you will lose the oil feed to the rockers with the inevitable results.

andreasb 1 Dec 2002 19:08

Hey you guys,

Just did a little 2 week whirlwind tour of India with a friend of mine and are now, unfortunately back in Delhi... heading to Rajasthan tomorrow. Will try to hook up with Marteen in Goa for Christmas...
Sorry to hear about your alternator... but it seems that you are prepared for almost anything heading your way...
Ripped any panniers of your bike lately...

I almost got mauled in Delhi dropping my friend at the airport... some tailgating lunatic decided to bumb into me from behind at 50km/h... Tesch panniers took most of the brunt... and I somehow managed to stay on the bike...almost dragged the guy out of his shitty Huyndai...and strangled him with his prayer beads... but he was so blissfully unaware of what had just occured...he actually thought I stopped in the middle of the road to have a chat about my bike with him... it almost made me laugh out loud if I wouldn't have been so shaken up...

Anyways, keep up the pace guys and let me know who you are using for your shipper in Kathmandu... I will linger for a few months in India before heading to South East Asia and Australia.


cheers and ride safe,
Andreas


Hi Andreas

Where and how the devil are you???? We're in Varanasi heading Kathmandu.

Our plugs go rusty red too, so must be something to do with the fuel over here????

Also, lost one alternator rotor - now there's a suprise. We were of course carrying a spare and extractor tool! Need another spare one now in case mine goes.

Cheers


[/B][/QUOTE]


andreasb 1 Dec 2002 19:18

Sorry for the delayed reply.
And thank you all for your great suggestions.
Turns out that the red spark plugs really came from the shitty petrol in Pakistan... and the starting problems were not electrical... battery is still going strong... seems like a clogged K&N airfilter was the culprit...and water in the fuel didn't help either (the over flow drain was clogged....)
Also, does anybody know how low /high the Octane of the standard Indian petrol is...I am getting some funky ringing when I'm pushing the engine a bit...
And I have not cleaned my carbs for the past 25000km...are there any posts on how to do this properly and how to get the carbs synchronized again...
Andreas

Grant Johnson 1 Dec 2002 23:43

The airheads site has a couple of good posts on this.

http://airheads.org/index.php?Technical%20Tips

See Synchronizing Carburetors, Rebuilding CV Carbs, Fuel System & Carbs Tips, $4 Carburetor Synchornizer and CV Rebuild Tips.


------------------
Grant Johnson

Seek, and ye shall find.

------------------------

One world, Two wheels.
www.HorizonsUnlimited.com


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