The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: badgertom on July 09, 2012, 12:42:53 PM
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I have a 1982 R65 which when the engine is cold requires me to push the starter button 2-3 times before the engine slowly to turn over at which time I give it gas to keep it going. The starter motor runs fine just the engine is sluggish. If I shut the engine off and restart after a short while the engine starts just fine ( because it's still warm??) Anyway what should I look at first inorder to get the bike to start properly if it is cold. I should add that carbs were balanced 3 weeks ago and spark plugs look okay..but not new.
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I had similar symptoms on my 1982. Turned out to be combination of two things. First, the ignition coil was cracked. Before I changed the coil, the bike was hard to start, and would fire up on one cylinder before the other kicked in. Even after replacing the coil, it was still difficult to start. A little while later, I discovered that the starter was on its last legs. Apparently the combination of the current needed to turn the worn starter and the fire the cylinders was too much for the system. Since I replaced the starter, it has been fine.
Another thing to look for is the spark pug wire. If it is original, it is shot by now.
Other possibilities include the enricher on the carbs or the setting on the carbs. You indicate that the carbs were recently balanced - was it done on a hot engine? You should take it for about a 20 minute ride before setting the carbs, otherwise it can be hard to start.
k_enn
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What is your starting technique ?
Every bike is different, but the usual starting technique, is fuel tap on, half to full choke, operate the starter, don't open the throttle, until the engine fires, then a quick opening of the throttle to get the engine running .
I agree, to look at your ignition coil, if you have a black and gray coil, replace it now, it's a known problem part, when the case cracks .
How old is your battery ?
Also, where do you reside ?
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You need 3 things to start an engine: Fuel mixture, A spark and compression.
The Choke (enricher) relies on a clean enricher jet in the float bowl and a good seal on the float bowl gasket.
You can test for a good spark by pulling the caps and inserting a pair of spare plugs. Then crank the engine with the plugs bodies earthed to the cylinders and check for a strong blue spark. Doing this by removing the existing plugs is not a fair test as without compression load the engine will crank faster and the battery voltage while cranking will be higher. For the brave owner of a good pair of rubber gloves an even better test is to hold the spare plug in series with the installed plug which tests for a spark under compression conditions. If the plug in the engine doesn't spark the one on top of it won't spark either. This is a very realistic test which tells you for sure if the installed plug is sparking under cranking conditions.
One thing sometimes overlooked as a cause of starting problems is closed up valve clearances which can cause compression loss.