TECH TORQUE : AIRBOX DRAIN AND CRANK VENT MOD

[Andyman]

This project is to vent the crankcase to the top of the airbox and to make a drain plug at the bottom of the airbox to drain oil and water as necessary.
The entire DIY project is a one man job, can be done in your garage and costs under R100.oo.
The purpose is to make your engine safe from water ingress.

WARNING if you bike is under warranty- you void your warranty by doing this job.

An inherent risk in  adventure riding is the deep water crossing.
Great fun, but unless very careful you can drown your engine and do permanent damage.
The 1150GS range had an airbox drain plug and the crank vented into the top of the airbox through a gooseneck rubber hose.
I never had a problem with deep water crossings on the 1150GSA.

Stats show that 75% of all GS bikes never or rarely go off tar.
Designers also realised the original Camel-Man is all but extinct as his habitat diminishes due to urbanisation and road tarring.
Therefore designers felt it was not necessary to engineer the R1200GS range for more than rough gravel roads.


The air intake horn opening sits  just abaft and above the suspension wishbone.
The wishbone channels water up into the horn in deep water crossings.

A snorkel works but it reduces road performance and you need to take it off when not crossing deep water.

So I followed the advice of other posts on Adventurerider.com and fitted a new crank breather.
I just cannot take it that the airbox drains direct onto the cam chain in the left bank. That was a no-brainer!!

https://advrider.com/forums/showthread.php?t=520523&highlight=airbox+wate... - post by CamoJo, post #48 to #57.



I bought  the necessary hardware for less than R100.oo

480mm of 20mm automotive rubber hose
two threaded plastic 20mm irrigation elbows. one male thread, one female threaded.
A tube of silicon sealant
A steel 21mm washer
A 20mm rubber stool foot

The tools I needed :-
A 21mm hole saw
A hand drill
A waterpump pliers
Towelling to clean up oil spill
A wet rag to lay in the airbox
Torx drivers for the side panels

What to be careful of
Drill the 21mm hole in the airbox where it will not interfere with seat fitting.
Fit the new 20mm hose behind the throttle body carefully and do not distort wiring.
Lay the wet rag properly in the airbox to catch plastic waste and in case you drop the washer or elbow.


The process
Remove the seats,  the panels left and right and place them safely out the way.
Keep the torx bolts in a tray or zip-lok bags.

Note the bolt lengths so you can pout them all back in the right places.
Remove the air intake horn and air filter element.
Lay the wet rag all over the inside of the airbox.
Drill the 21mm hole as far up high and forward as you can without interfering with the air temp sensor.
Before drilling place the LHS panel in situ and with a koki map out where the seat tab slips in. You need to leave space for the tab or your seat will not fit properly.

Test the fit for the two elbows. I ended up reducing the profile of the outer one (female thread) to make it fit closer to the box and reduce profile.

Then put the washer in place on the male threaded 20mm elbow
Smear silicon sealant on the washer and thread where they mate with the airbox wall. – reach into the airbox, push the male thread through the airbox wall and screw the outer elbow into place.
NOTE: you want the outer elbow to point downwards and slightly forwards.
You want the inside elbow to point downwards and slightly to the rear. This helps for when your bike falls down on a negative slope by preventing oil running  too freely up the pipe and into the airbox.

Now using the water pump pliers remove the existing crank vent hose from the airbox and from the cam chain cover.
Place this carefully in a bag and keep it in case you need it in years to come when selling the bike.
Use the towelling to clean up all the oil smudge and smear- oil has been running up this vent pipe and it has become tacky and oily.

Now thread the new 480 mm long 20mm pipe up from below behind the throttle body and fit it to the elbow up top.
Fit it to the cam chain cover using the same clamps.
Push the 20mm  stool foot onto the outlet pipe of the airbox. This snug fit will not fall off and you can drain the airbox from time to time or to quality check the condition of things in there.

When you now go through a deepwater crossing, remove this plug just to be sure there is no water.
When on  the side stand this is the lowest point and any fluid will drain.

Replace all the panels neatly and admire you handywork.
It is unlikely anyone will ever notice this mod unless you point it out.

 

[Andyman]

 

[Duke916]

 

[Chrisl]

 

[Andyman]

 

[Andyman]

 

[Adventurer]

 

[Andyman]