Could use some help on R1100 engine issue

[Joeaksa]

I have a 1995 R1100RSL. Yes I know its an oldie but a goodie as well.

Just had the bike all tuned up and done by a very good shop here in town. Rode it about 80 miles and it ran great.

Let it sit for a couple of weeks while I was out of town and then took it out yesterday for a ride.

When it first started up it only ran on one cylinder but that happens from time to time and usually clears up in a bit. This time it did not and persisted when I rode it about 100 yards and back to the house. Finally started idling on both so I hopped on it to ride to the corner store for some fuel. It had a half tank but thought that it could be an indication issue so lets fill it up and make sure.

It would cut in and out and backfire from time to time on this ride, and did not change with a full tank of fresh fuel. Started running better but not great. Ok lets take it out for a bit and see what happens and it started getting better but not great then 5 miles out started running on one cylinder again.

Turned around and got the bike home but something is not right. Have ridden BMW's for 35 years and the newer models since 1994 when they came out. Never had this issue and thinking I have an electronic or spark issue...

Any ideas or suggestions?

Thx, Joe

[wswartzwel]

Check the plugs for a fouled one yet?

[Drews323i]

Check Plugs, plug wire, coil, HES. It sounds like a coil breaking down Or a plug wire shorting.

[Joeaksa]

Drew,

Exactly what I was thinking but have no experience working on these... airplanes yes but not the new "oil-heads" just yet.

Bill,

That is my next move. Rick Lee stopped by the house today and of course when I start it up for him it runs fine but we did not ride it yet.

Do the plug wires just pull straight off? We pulled the plug cover off of one side and I tried to pull the plug lead off and it did not come off easily so did not fuss with it anymore. Its dark here and not going to fiddle with it out here in the dark...

Thx, Joe

[wswartzwel]

Watch Rick... he is liable to shoot it.

[Joeaksa]

Originally Posted by wswartzwel

Watch Rick... he is liable to shoot it.

Rick is a pretty good friend and I would have to agree!

[8ball]

You have one coil that fires both plugs at he same time, if it was the coil both cylinders would quit, more likely a plug or injector. when it starts one one cylinder feel which header is cold and then trouble shoot that side.

[Joeaksa]

Originally Posted by 8ball

You have one coil that fires both plugs at he same time, if it was the coil both cylinders would quit, more likely a plug or injector. when it starts one one cylinder feel which header is cold and then trouble shoot that side.

Good to know. Will pull the plugs and see what that shows (if anything), then I have an IR heat gun and will see which exhaust is warmer when it starts to do this.

Thx! Joe

[Bob Hancock]

Originally Posted by Joeaksa

Do the plug wires just pull straight off? We pulled the plug cover off of one side and I tried to pull the plug lead off and it did not come off easily so did not fuss with it anymore. Its dark here and not going to fiddle with it out here in the dark...

Thx, Joe

Yes....pulls straight off but takes quite a tug. So much so that BMW sells a plug lead puller that is way better than the crappy thing in the tool kit. Just be ready when it lets go because it's easy to pull the connector off.

[Dr. Curve]

Plug wire puller came in the original tool kit for that bike. I remember getting the first RSL around these parts and simply not being able to pull the plug wire without using BMW's handy little tool kit "straight pull gripper tool." Just like Bob said however, with the proper tool...........it simply flys off! Go to AC plugs with a big broad tip as that engine seemed to like them.

[Joeaksa]

Plug wire pulled right off but of course that was using the BMW tool in the toolkit! I have a aftermarket one that we use on others and its too tight to get it in there.

Plugs look pretty good. Coloring is fine, gaps are fine, and not fouled at all on either. Still not sure how old these are so going to swap them out just in case one is breaking down at times or high loads.

The ones in there now were Bosch FR6DTC's. Any suggestions on anything better? I believe that the stock plugs were FR5DTC's.

[Phil Y]

Check plugs first as Bill suggested. Then figure out which cylinder isn't firing and switch stick coils-one could be going bad.

[Joeaksa]

Originally Posted by Dr. Curve

Go to AC plugs with a big broad tip as that engine seemed to like them.

Thanks and found that several BMW riders on the 'net recommended the Autolite 3923 model. Cannot find any cross reference for an AC plug. Any hints?

Thanks!

Joe

[Joeaksa]

Phil,

Where does one find the "Stick coils?" I assume follow the spark plug wires? Hope the tank does not have to come off... thats not a lot of fun and its full right now!

Am going to start with the plugs (they prolly need it) and go from there. Right now unfortunately both cylinders are firing for a change!

Thx, Joe

[JimMoore]

No stick coils on that model.

The Autolite 3923 is available everywhere. Every auto parts I've ever been to has them for sale.

Depending on what hasd been done to that bike there are a host of mid-life issues you could be having. Spark plugs aren't a bad place to start. Then I'd be thinking about the fuel filter. Then the fuel lines inside the tank. You might as well swap out internal lines and the filter at the same time. Plug wires might be an issue, as might the HES. If neither of those have been replaced you should consider it to keep from getting stranded somewhere. There is a chance the coil has gone bad, but that's unicorn-rare.

All that being said, I'm a fan of looking where I worked last. Maybe the plug wire wasn't seated and you've fixed your problem. If it was a major engine issue it wouldn't appear and disappear, so it doesn't sound like anything big is wrong.

[Joeaksa]

Jim,

Its a box stock bike as far as I know of. Bought it 4-5 years from the original owner who lived out in the stix far from any dealer.

Will stick some new plugs in the puppy and go from there!

Thx, Joe

[Phil Y]

Jim, maybe wrong name but ignition tubing (stick coils) are between the plug and wire, inside the head cover. About four inches long. It's #2 in Diagram 12_0769 here. Idea is if nonfunctioning cylinder changes when you switch them, then you've located the prob.

[Bob Hancock]

Originally Posted by Phil Y

Jim, maybe wrong name but ignition tubing (stick coils) are between the plug and wire, inside the head cover. About four inches long. It's #2 in Diagram 12_0769 here. Idea is if nonfunctioning cylinder changes when you switch them, then you've located the prob.

Learn something new every day. I didn't think those things were anything but extensions to reach the plug.

[Phil Y]

Awfully expensive to be just a connector! New one helped cure my ignition woes.

[JimMoore]

I think "ignition tubing" is simply a fancy name for spark plug wires. I've never heard of anyone discussing "stick coils" in the single spark engines. Dual sparks, sure.

Did they sell you just the end piece? On a single spark?