Fuel line and Mac 2 into 1 exhaust.

[beemermark]

I was replacing the fuel lines on my '83 R100RS and pulled the fuel line out that runs under the air filter housing connecting the two carbs. Course I can't get the new one to slide in. I'm afraid replacing it means removing the filter and filter housing (which bolts to the trannie) and is probably a 2~3 hours job. Anyone have any suggestions on how to snake the fuel line under the filter housing without removing it?

On another note I see that Mac Exhaust still sells new the two into one exhaust system for the R100. They look great but is there any downsides? Performance? Oil filter removal? Lower fairing interference?

 

[GACOACH]

Piece of straight wire - like from a clothes hangar - slide inside the length hose you precut for the crossover.

 

[beemermark]

Piece of straight wire - like from a clothes hangar - slide inside the length hose you precut for the crossover.

I'll try it.

 

[sumran]

Pulling the airbox is not as bad as you expect. You will become become highly skilled at it if you do your own work on an airhead for any length of time. I don't remove the airbox for this job, but I do loosen the bolts to allow some movement.

 

[TGHSMITH]

cut the crossover line about an inch longer than needed but at a slant , push it through grab the end with a needle nose, pull it out , cut the end straight, install fuel tee's.

 

[barryg]

Mac 2 into 1 exhaust

Pulled out an old Mac sells pamplet. Add states access to all service points, centerstand retention, big bag clearance, installation uses stock mounts. Good view of right side of bike with system. From the picture it looks like a tight area for filter change. The system looks kinda cool though. I tend to doubt any performance gains. I guess U get less weight with one less muffler.

 

[TGHSMITH]

if I remember correctly only the 2into1 made by CC products could be used with the bmw lower fairing sections...

 

[jforgo]

Sparay old and new line exterior with silicone spray - connect new line to old with straight connector - push thru with clean screwdriver which fits line but hits connector while you simultaneously pull on old line.
However, if you pull airbox to do this, you are 1/3 way to spline job - when was this last done? If you don't know, then it is time.

 

[lkchris]

Installation of an aftermarket 2->1 exhaust system consistently reduces performance.

BMW's middle name ain't "motor" for nothing.

 

[535IS]

I was replacing the fuel lines on my '83 R100RS and pulled the fuel line out that runs under the air filter housing connecting the two carbs. Course I can't get the new one to slide in. I'm afraid replacing it means removing the filter and filter housing (which bolts to the trannie) and is probably a 2~3 hours job.

I dunno; maybe I'm missing something obvious, but it takes me something like 15 minutes, including a little cussing at the stupid clips it slips under on the alternator housing ... or is that the top of the gearbox? Keep in mind I'm not only new to this Airhead stuff, but a complete idiot, as well.

 

[LOSTBOY]

MAC Exhaust

Unless MAC has changed their design, it is impossible to access the oil filter or ignition cover.

 

[dennisdarrow]

In total agreement with 535 and Randy about the ease and need for an owner to be able to remove the "Airbox"...............This is something so "nothing" a job that it leaves me wondering about folks. Each to his own I guess; but baffling and laughable.................

The hardest part for me in this little task is aligning the carb tubes upon reassembly. Putting them back on without crimping the tube, for me, is a total pain; but easy with a bit of care................

Good Luck.............Dennis

 

[sumran]

In total agreement with 535 and Randy about the ease and need for an owner to be able to remove the "Airbox"...............This is something so "nothing" a job that it leaves me wondering about folks. Each to his own I guess; but baffling and laughable.................

The hardest part for me in this little task is aligning the carb tubes upon reassembly. Putting them back on without crimping the tube, for me, is a total pain; but easy with a bit of care................

Good Luck.............Dennis

If you have never done it, it looks like more than it is. Especially on the models that have the emission control equipment embedded in the airbox. The emission control plumbing hampers access to the bolts that attach the airbox. So I can understand beemermark's time estimate.

I hear you on the carb tubes. I have not yet mastered the quick easy installation method yet. I assume there must be one. If anyone knows the magic method, please share.

 

[lkchris]

I hear you on the carb tubes. I have not yet mastered the quick easy installation method yet. I assume there must be one. If anyone knows the magic method, please share.

Carb tubes are dead simple on the '80-on bikes.

Just slide the big rubber tube down onto the tube, put the tube on the carb and in place next to the airbox and slide the rubber tube up and on.

I've forgotten how it is on the earlier models.

 

[sumran]

Carb tubes are dead simple on the '80-on bikes.

Just slide the big rubber tube down onto the tube, put the tube on the carb and in place next to the airbox and slide the rubber tube up and on.

I've forgotten how it is on the earlier models.

Thanks. That is how I attempt to do it, so I am glad that I am on the right track. Based on your experience(easy installation with the same method), I must have something else wrong that is complicating things. There are some alignment issues. Perhaps I have some other parts improperly installed and that is throwing off the alignment.