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1975 r90/6 starting issues...

soflopro

SoFlo MoFo
1975 r90/6 been running for a few years, with issues here and there, but she always seem to start(even if i had to push) until recently... a few months back i had a leaky brake mc, it flooded the starter relay. got the relay cleaned and rebuilt the MC, everything worked fine after. most recently the bike didnt want to start when i pressed the button, tried again, and again... just a faint click.. i rolled the bike a bit and wham! it turns the motor!!! this became a frequent thing... try to start the bike, press the button, just a click... rock the bike back n forth a bit... ouala!!! it starts! I was lazy to figure it out, until the battery started showing signs of low voltage... so i charged up... same old same old... soon after battery is low again??? i have to push start the bike a few times.. no problem, then one day it wont start at all...??? now all i get is the click again... let me add that the engine is NOT in the best condition... but it would start fairly easy all the time. weather wasn't cold at all, when i push started it was on a hill so it was easy every time... until it didn't.

now the last i tried was to clean the starter relay contacts and check all cables and connections for damage or build up. still all i get is a click from the starter relay...

battery is fully charged, when i try to start the volt meter doesn't change? i still hear the click from the relay, but no change in voltage at all.???

could it be a bad starter? or just a connection issue at the starter? or is the relay bad?
or both?
bad compression, old spark plugs, lots of leaks probably dont help much huh? sometimes i wonder why i even post on here... oh yeah i dont have the money to fix it all at once and i just want to ride the damn thing!!!!
:doh
thanks
:ear:banghead
 
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Is there any way you can use another battery to jump start it? Sort of sounds like it might be a bad battery, but I totally understand about the expenses. So, if you could rule out the battery by using a different one and seeing if the symptoms change, might help to ensure you don't spend money unnecessarily.

Barron
 
When you say you rolled the bike forward, was that with the tranny in neutral or clutch pulled in? If so, that did nothing to affect the starter IMO. You would have to push the bike in gear so that the flywheel/cylinders change their relative positions.

Have you watched the battery voltage across the terminals when you tried to start? If it plummets to 8-9v when starting, it's a bad battery. What about the voltage reading with the engine running above 3K RPM? Should be pretty far north of 13.5v. If not, then you're not charging your battery up between starts.

You will probably need to use Snowbum's methods to find out where the 12v is disappearing in your starter circuit. That will tell you what to fix/replace.

http://bmwmotorcycletech.info/startingprobs.htm
 
after further testing...

i tried to jump start using my car, same result... checked voltage with meter, same results... next thing i tried is jumping the starter at the solenoid... now ive got something! turned the starter and the engine! checked that i was getting spark to each plug fine, ran the motor a bit. after turning the motor off i tried again to start with the button,,, same result, just a click from the starter relay. Bad Solenoid???or bad relay? last thing i tested was jumping from the bikes battery straight to the solenoids switch connection (cable coming from the starter button). thats turned just fine... making me think the solenoid is working just fine....? any way to test the relay?
 
resolution!

thanks to all for your input and your patience. Turns out it was the starter relay, i tested and tested, pulled apart the relay and cleaned the crap out of it (literally- it was really corroded inside)... more testing... turns out the relays contacts were worn and not connecting. the electromagnet still worked and would move the actuating arm, but no contact was made, therefore no juice to the starter!! after a bit of mcguivering, i stripped a wire down to 2 filaments, then wrapped them around the contact. now the when the actuating arm moves it makes contact on the wire... temporary fix, but it allowed me to truly understand where the problem was.now the bike starts right up even with a mildy low charge after sitting for a few months!!! now all i need is to rebuild the engine. . . any suggestions on steps to take? i need new seals, lots of oil leaks, and am looking into new pistons, valve reseating, hopefully not too much else
 
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