Keep Your Revs Up!!!

[boxer54]

Hi
I'm quite new to boxers and the forum but my 1986 R80 Mono has been suffering from the old electrical/ charging gremlins.

The main problem was with erratic starting and the old familiar click clicking/ machine gun rattling/ of the spinning starter, (it is the starter/ solenoid right?) and the engine not catching. Sometimes it would, sometimes it wouldn't.
I'd ride for an hour or more park up, come back to the machine a couple of hours later and click click but no catch.

I started at the beginning and changed the battery for a new one. The problem was solved...for a while. I rode off into the sunset in ignorant confidence, telling myself, "That was easy..." only to find my bubble popped again clicking outside a cafe 15 miles from home, heart sinking thinking about the cash I may have wasted. I invested in 'Classic Boxer Charging Systems' by Rick Jones from MotorWorks. The bike has only covered 32000 miles so I thought a dodgy starter was unlikely, corrosion and loose cables too were not an issue...

Then I read about RPM...and that the boxer engine's alternator spins at the same speed as the engine....only actually begins to send charge around 3500 RPM!! And that optimum charge is reached at 7000 RPM!! Is this true, I thought? But I love the torque through the gearbox, sitting at 2000 RPM in 5th, and the lazy draw of the engine.

Sure enough though, since reading that paragraph, I've been riding conscious of the 3500 RPM line and I have not had a starting issue at all.

Its a rambling post I thought I'd put up for those like me who may be having charging niggles. I know there are numerous other electrical gremlins ready to jump out and my two bits worth is KEEP YOUR REVS UP

safe riding

[Kurt in S.A.]

You might want to invest in a good volt-ohm meter and actually see what the voltage is at the battery under various circumstances. At rest (before and after a ride), during starting, at idle, at 3000 or 4000 RPM (before and after a ride). That will really tell you what's going on. You may only be seeing 13.5v at the battery in the best of situations...you'll need lots of steady highway driving to fully recharge the battery. It should be closer to 14v.

Or you can invest in a battery tender and head on down the road!

Kurt in S.A.

[wookie]

After a cold start, it takes up to 50 miles at highway speeds to fully recharge your battery. That is with a charging system in top condition. If you do lots of short rides, follow Kurt's advice; invest in a battery tender.

Wookie

[daz]

After a cold start, it takes up to 50 miles at highway speeds to fully recharge your battery. That is with a charging system in top condition. If you do lots of short rides, follow Kurt's advice; invest in a battery tender.

Wookie

I agree Wookie. But I would only use a real battery tender like the Deltran or some other device that reads your voltage. Personally I would not trust the Chinese tool company's less than $10 charger. Investigate battery tenders. Good luck.

[Garnet]

OR get a voltage red that will allow the system to run 14.2 to 14.4V.

I have run my ex /5 all winter as a daily driver, using a 280W alt, a 14.2V reg, a small (swb) battery, a modern PMGR starter and only 15 minuets of headlight on ridding at a time, and never needed an extra charge.

But, I would, from time to time, take hour long runs on the weekends, and I did have an AGM battery.

And the above statements, that it takes several hours of run time on ANY charge system to fully charge a battery is true. The trick is to not let a battery run down.

[jagarra]

I finally went to this style float charger, those cheap units from Harbor Freight are not good. I had a bunch of them, output went from 12 v and down to 9 volts. Finally threw them out a went to this unit.


http://www.amazon.com/Battery-Tender-02 ... at+charger

[Primate]

But I love the torque through the gearbox, sitting at 2000 RPM in 5th, and the lazy draw of the engine.

You're not alone. I'm also guilty for the same reasons. Thanks for the info. My daily commute is 20 miles each way, and my Yuasa tender, which I use religiously, has been great.

Welcome to the board--great people here.

[Chuey]

I too, like the torque of the BMW engine. Only thing is, and maybe this comes from driving aircooled VWs my entire adult life (so far), the engines are not meant to be lugged. They like to sing and run.

On another site, I can't remember which one and no, it wasn't Alzheimers.com, I read of a rider who didn't like the BMW R1200RT. Upon reading all that he wrote, I determined that he was lugging the everloving heck out of the engine. Same thing applies.

These bikes like to run. Give them some freedom and run them. You can feel it if you listen to what the engine says to you.

Chuey

[Deleted User 287]

I never owned a battery tender when I had the R65, but it's engine liked to rev more than the Type 247s and was willing to rev it.
I did have an Odyssey battery in it though, which I put the full-sized car charger on it a few times a year.
Before the Odyssey, I used Yuasa batteries, which were worlds better than the OEM batteries I suffered with for 10 years before switching.

When I bought the CBR250R the dealer installed a pigtail on the battery for a battery tender. I don't understand why he didn't try to sell me one, as I ended up buying the large version at Amazon: http://www.amazon.com/Battery-Tender-02 ... B00068XCQU

Now, when I get home from work, I just plug it in, and within 20 minutes I have a solid green light.


But, OP, just because you have low mileage is no reason to not suspect corrosion under the insulation of the starter cables or loose connections.

[chasbmw]

I too, like the torque of the BMW engine. Only thing is, and maybe this comes from driving aircooled VWs my entire adult life (so far), the engines are not meant to be lugged. They like to sing and run.

On another site, I can't remember which one and no, it wasn't Alzheimers.com, I read of a rider who didn't like the BMW R1200RT. Upon reading all that he wrote, I determined that he was lugging the everloving heck out of the engine. Same thing applies.

These bikes like to run. Give them some freedom and run them. You can feel it if you listen to what the engine says to you.

Chuey

I agree thatnyou must listen to whatnthe engine says to you but Lugging an engine is by a combination of too much throttle at low revs, it's not JUST an rpm issue, both my bikes are really good low rpm performers and with sensitive throttle control will pull happily from as low as 1500 rpm. Its one of the things that make the bikes so good to ride off road and in our congested towns in the UK. Probably having fully balanced engines and dual plugs help.

I have a feeling that a stock BMW charging system reaches maximum output at around 3000 rpm.