Popping through exhaust

[thessler]

Hi
I'm just getting this new to me bike running, the left exhaust pipe is popping .
I did check the valves and adjusted, I think that made it worse.
I removed the EPA line to the head and the popping stopped , reinstalled and it started again.
I have no problem tossing it and welding up the hole. My question is does this indicate a larger problem on the horizon ?
Some subtle indicator that something is not right or about to be not right ?

One other question, when I checked the spark its lame !! It's very weak almost thready.
Is this normally how these bikes are ?
If this was a car you would start replacing parts, but I know some bikes are funny that way. And yes even with a weak spark it starts and runs.

Thank you for any info, Tom

[Barry]

I'll let those with experience of an EPA system answer the question properly but popping in the exhaust means air leaking in someplace.

On the spark what ignition system are we talking about.  Points with twin coils or electronic with a single dual out put coil ?

[Bob_Roller]

You can remove the entire system from the bike .

The threaded holes in the head can be filled with an oil drain plug and crush washer from an oilhead .

There's nothing wrong with your engine, the EPA system had that effect on a lot of engines .

There's a recent thread about this system at the bottom of page in this section ,

[thessler]

Thanks
This is a 1984, I don't know what ignition system or coils are in it, too late now to go out and check.
I'm guessing all 1984 would be the same ?

I will updated profile when I figure out how, I looked at it and didn't see a spot for bike info.

Thanks for the link on the EPA stuff, will pursue it tomorrow.

   Tom

[Barry]

An 84 has electronic ignition with a single dual output coil so no way should you have a weak spark.

To eliminate the plugs caps and ignition leads, is it weak on both Sides ?  If it is then the coil may be suspect.  

[thessler]

Ok thanks Barry
It does have very weak spark on both sides, I'm kinda surprised it runs.
Wires look good, plugs are new.
I guess I'll try to find out how to test the coil.
Thanks, Tom

[georgesgiralt]

Hello !
Look at the connection of the plug cables at the coil. If the bike had sit for long under humid condition, the copper at the coil may be corroded.
Sand paper, first, then contact cleaner and maybe the spark will benefit from this.
If the coil is the grey plastic enrobed one, consider changing it it may be cracked and have broken the very thin wire inside.

Bear in mind that the replacement coil from BMW (Bosch, metallic) REQUIRES the latest ignition module or will kill the module !
So if your coil is cracked, try to fin a Fiat Punto coil (fits perfectly) or an after market dual output coil with 1.3~ 1.5 Ohm primary resistance.
Either case, if the wires are old, buy new ones. They have a hard life.

[Bob_Roller]

What color is the ignition coil, if it is black and gray, replace it now, it will fail on you at the most inopportune time, usually in wet conditions .

DYNA 'brown' coils are a popular aftermatket replacement part .

[thessler]

I just went out and checked on the coil.
It is literally cracked in half between the plug wires completely around the coil. So I'm guessing even though it works its bad.

This is a red coil and and it says 1.5 ohms on it. There is no mounting bracket. It had four tye wraps holding it to the frame !

Can anyone tell me if this is the proper coil for this bike, if not what coil should I order ?

Thank you for the help, Tom

[Bob_Roller]

You need an ignition coil that has a 1.5 ohms resistance on the primary circuit .

There is a BMW coil available, it's red and black, cost is around $140, the DYNA coil, is around $95 .

It sounds like you may have a DYNA coil on the bike now, but obviously not correctly mounted .

In North America, this business has the DYNA coil mounting hardware ans mounting bracket .

Shipped by USPS Priority Mail and gets to  you within two days or so .

http://www.motoelekt.com/ignition.htm

Scroll down to about the middle of the page .

It's a popular replacement for the OEM coils

[montmil]

Call Rick Jones at MotorradElektrik http://www.motoelekt.com/ignition.htm

Tell him you want a Dyna "Brown" coil for your '84 R65. Yes, they look orange but... Also suggest you go ahead and replace the plug wires even if they "look good". NGK sparkplug caps will finish off the other end of the plug wires.

Rick can set you up with all the goodies. One-man operation in northern Alabama so be patient and let him get to his phone.

[thessler]

Thanks very much guys.
I just ordered the coil, the guy was great very helpfull.
I think that's all my questions for now.

  Tom

[Session101]

hey was your popping sound coming from the exhaust, a loud one or more of a soft bubbling?

[thessler]

Session
It was not loud, it was a distinct crisp pop. Not really a bubbling .
I removed the air system but have not started it yet, I am waiting for a new coil.
  Tom