Triumph Bonneville Mods for Airbox Removal

The Stock Airbox
Unfortunately the airbox can't be done away with completely because it holds the battery, acts as part of the rear fender and is a mounting point for various parts and systems. While the airbox removal kits offer a machined replacement to hold the battery and relocate mount points, we can do the same thing for much cheaper by chopping up the stock airbox. When cutting we have to carefully work around important features removing only as much as we need to fit the new air filters. I prefer not to destroy the stock parts on my bike so I ordered a spare airbox to tear up from a salvage parts dealer.

The battery box supplied by the kits provide a very minimalist replacement but as you're not using the space under the seat for anything else you may as well get creative with it. I decided to turn the air filter into a tool stash by tearing the pleats out with pliers. I clipped off the top and fitted some 1/4" vinyl tubing around the rim to keep it snug in its nook.

To make room for the new air filters, I had to cut from the front of the battery compartment, down and around the old-air-filter-turned-tool-kit. I used an angle grinder to cut most of the material off and then a hacksaw for the details. Both worked through the soft plastic like warm butter.

If you are planning to use the old air filter, make sure not to cut off the splines that hold it in place!

On the right side of the airbox are the rear brake reservoir and fuse box mounted on a metal bracket along with the carb heater relay press fit beneath the fuses. On the left side are two relay boxes and the starter solenoid. To make room for the new filters, the fuses, carb heater relay and starter solenoid all have to find new homes on the airbox. While deciding how best to go about doing this, my girlfriend hit upon the idea of using heavy duty velcro. This is great because it makes getting around the airbox for other maintenance much easier. Since the rubber mounts on my relays were toast, I decided to velcro those as well. The starter solenoid was relocated right next to the relays, while the fuses and carb heater relay moved to the front-facing side of the airbox.

A quick note about removing/installing the stock airbox: although I saw some posts online in which folks claimed to remove the stock airbox without removing the rear wheel, I was not able to do this. In the end I removed both springs, the rear fender, the left muffler (to access the axle bolt) and the rear tire. The extra space makes it much easier to fit the airbox and associated wires, hoses, etc. comfortably.

And that's all there is to it. Be sure to follow the manual closely when reassembling the rear of the bike. Don't forget to check the rear wheel alignment and tension the chain correctly before tightening the axle nut and make sure that everything is snug before calling it a day.

Triumph Bonneville Air Injection Removal

Secondary Air Injection System

Parts needed:
2 M12x1.25 bolts
2 crush washers

Total cost DIY:
$8.00
Cost at newbonneville/british-customs/bellacorse:
>$25.00

The SAIS is an emissions control system that pumps air into the exhaust to burn up any fumes that made it through combustion. Air travels through a hose from the airbox to a valve mounted on the frame above the engine and down two tubes that enter the cylinder next to the spark plugs. In order to aid combustion, a small amount of emulsified gas mixture is extracted from the left intake through a ribbed hose and also injected into the exhaust. Removing the SAIS is simply a matter of pulling it off the frame and plugging the holes where the hoses enter the cylinder.

Getting the SAIS out of the engine block is a little tricky if you don't want to mangle the metal tube because the hex is recessed and very close to the valve cover. Start by pulling the hose off of the reed valve.

Now turn the tubing around to expose the pinched hose clamp.

End-nipper pliers are good for opening these incredibly irritating hose clamps.

Now you can slowly ease the angle tubing leaving just the section that is screwed into the engine.

I slid an offset 13mm wrench down the tube to get at the hex. Be sure lay a shop towel down because you're probably going to smash the wrench into the cam cover when the threading breaks loose.

The hole left by the SAIS can be filled with a M12x1.25 bolt. This is a pretty uncommon size (at least in the US) but luckily it is the same spec as the drain plug for many Japanese car models. You can find one for a few bucks at your local auto parts store. Don't forget to buy M12 crush washers as well!

If the drain plug is too long or has a stub (like the one I got) you can cut it down to size with an angle grinder.

The crush washer is extremely important as this bolt has to seal the against the exhaust pressure. Aluminium and copper are both good choices. Remember that the space around the SAIS hole is very limited so the washers should be small. The two washers pictured below were too wide and I had to go out and buy new ones. Save yourself the extra trip!

Simply bolt the drain plugs into the engine and you're good to go!

Triumph Bonneville DIY Air injection and Airbox Removal

So I know that airbox removal has been pretty much beaten to death (at least by the Triumph community) but as I managed to save quite a bit of money doing this myself (not with a kit) I figured I'd document it. This modification replaces the stock airbox with individual air filters clamped onto each carburetor intake. The airbox snorkel and internal baffle restrict the flow of air into the carburetors; by removing the maze of plastic, we free the carburetors to draw in more air resulting in a modest performance increase. I'm going to skim through the steps that are explained elsewhere and focus on the parts that involve a little creativity and ingenuity.

For starters, airbox elimination consists of a few distinct parts. In no particular order (click the link for a detailed walkthrough):

the stock airbox has to be chopped to make room for the new air filters;
the carburetors have to be re-tuned to adjust for the increased airflow;
the secondary air injection system should be removed;
the carbs have to be braced against the frame;
the new filters need to be installed;
the crankcase breather hose must be re-routed and fitted with its own filter.

Finally, the carburetors need to be balanced and and adjusted until everything is running up to spec.

Instead of compiling one monolithic article, I've broken these down into a few self contained posts to keep things relevant.

Parts
Airbox mods:
2 K&N RC-1920 air filters (54mm I.D.)
1 stock airbox
heavy-duty velcro

AI removal:

2 M12x1.25 drain plugs
2 M12 crush washers

crankcase breather:
1 K&N 62-1015 crankcase breather filter

2 1/2" hose clamps

15/32" PCV hose

For carb tuning:
main jets, pilot jets, needle shims

Carburetor Synchronizing on the Cheap

As promised, I have completely diverged from the topic of vintage computers. I recently spent all of my money on a 2005 Triumph Bonneville T100. My favorite thing about the bike is that it is incredibly simple - enough so that the only tools you really need to work on it are a screw driver and a set of hex keys. This is extremely fortunate because the Bonnie demands a lot of attention. The previous owner of my bike had garaged the it for a few years and when I bought it, the carburetors were completely gummed up. After driving it home on the choke, I (with the help of my indescribably tolerant girlfriend) had to pull the carbs out and completely overhaul them, replacing the jets, bowl gaskets and needle valves. The fact that I was able to do this with absolutely no experience at all is a testament to this bike's genius. However that's all another story for another day, and on that day hopefully I'll have a camera on hand to document it.

I've been noticing that my bike has been feeling a little underpowered, especially at low RPM. I suspected a bad fuel mixture (as I had played with the float height when overhauling the carbs) but the spark plugs did not show any signs of overly rich or lean combustion. The Haynes, which is worth every penny of the thirty bucks or so that it costs, suggests that unsynchronized carbs can cause lagging at low RPM. Synchronization refers to the difference in air pressure between the carbs. It is important that both carbs create the same vacuum, so that both combustion chambers receive the same amount of air/fuel mixture. I was a little discouraged by this because at a glance, synchronizing the carbs seems somewhat expensive. Syncing requires a manometer to measure the pressure between the carbs and the engine and these tend to cost around $100. Turns out, there's a much cheaper solution to the problem.

For the purposes of syncing, we don't really care about the pressure in each carb, only the difference in pressure between the two (or more depending on your bike). We can construct a simple tool to help us determine the difference consisting of a sump and some vinyl tubing. The idea is to connect the test ports in both carbs to a common reservoir and see which one draws more fluid. We can adjust the balance until both carbs draw the same amount of fluid and we know that at this point the pressure is balanced.

Bill of materials:
20' of 1/4" clear vinyl tubing (I chose 1/4" because it fits snugly over the test port on my Bonneville)
1"x2"x4' cedar board
~5 zip ties
~20 staples
~1 cup automotive lubricant

Grand total: <$7.00 at Ace Hardware

The manometer is incredibly easy to make. First fold the tubing in half and zip tie together.

Then (very gently) staple the tubing to the board. Be careful not puncture the tubing - it needs to maintain a vacuum! I separated the staples by hand and hammered them into the board.

Add a few extra staples at the top where the tubes diverge.

And the finished product.

It's important to leave a lot of extra tubing. If one of the hoses disconnects, the opposite carb will suck all of the fluid into the engine. Having extra tubing will give you time to kill the engine before this can happen! I opted for motor oil as the manometer fluid because if it does get sucked into the engine, it's not the end of the world. Any high viscosity fluid will do - this will help dampen sudden changes in pressure (i.e. blipping the throttle or dropping down to idle) and make for a more stable reading. Siphon enough fluid in to allow for  about 20" in play (depending on the weight of the fluid).

To use the manometer, attach each end of the tubing to the test port between the corresponding carburetor and intake. Make sure to connect the left hand tube to the left carb to avoid confusion. (Also, if you ever pull your carbs, make sure the rubber intake is oriented correctly when you resinstall them. Looking at this picture, I noticed that I put it in upside down...)

To sync, simply turn the bike on and watch the fluid in the tube.

If one carb is creating a harder vacuum, you'll notice the fluid level rise in that tube. Use the screw between the carbs to make the adjustment. When the fluid is level across the two tubes, you're done! Open and close the throttle a few times to make sure it's stable and you're ready to go.

A few tips:

1. Make sure that the engine is at operating temperature before syncing. This means the engine will be hot so mind your fingers when accessing the adjusting screw.

2. Increasing the idle speed a little may help, especially if the sync is way off to begin with. The "suck" cycle is longer at low revs so the pressure differential is magnified. As the sync gets closer, drop the idle for finer adjustment.

3. Gently open and close the throttle after each adjustment. The adjustment screw is on the throttle cable linkage so it's important to reset any inadvertent changes made by pressing on the screw.

4. If your bike is air-cooled be careful not to let it overheat. Without air passing over the radiator it won't take long, even at idle. You can run a fan over the radiator if the sync is taking a while.

Disclaimer: I'm not a mechanic nor am I an engineer - in fact I'm not even that technically inclined. The information on this blog is simply an account of my own experiences. You and you alone are responsible for your safety and well being. If you attempt to recreate anything you see on this blog, you do so at your risk; I am not responsible for any damage you inflict to yourself, others or your possessions. You have been warned.

Creating Persistent SSH Connections with TMUX

Persistent ssh sessions are the reason I began using tmux and yet I have still not been able to find a good tutorial on how they can be created. If you're reading this hopefully I can save you some time and you can start incorporating tmux into your bag-o'-tricks quickly.

First off, what do I mean by a persistent session? I want to be able to log into a remote machine, do some stuff, and log out without losing my running processes. Later, I should be able to log back in and pick up exactly where I left off. As an example, I am constantly running long simulations on the machine in my lab. I would like to be able to tunnel into my lab from home, start a simulation, and log out without interrupting the simulation. After a couple of hours, I should be able to log in again and check on the progress of the simulation. Simple enough, right?

Tmux allows you to do this by detaching a session. The important thing to remember is that the session lives on the remote machine. Therefore tmux must be installed (and running) on the remote machine. The tmux server takes care of processes that you started and `returns` them to you when you reattach.

So, in a few simple steps:

Log into your remote machine,

dkudrow@local_machine:~$ ssh dkudrow@remote_machine

Create a tmux session on the remote machine,

dkudrow@remote_machine:~$ tmux

After starting your simulation or doing some work, detach the tmux session. In the tmux command line enter,

:detach

No you can log out of the remote machine without interrupting the session,

dkudrow@remote_machine:~$ logout

To resume the session, log back into the remote machine and enter,

dkudrow@remote_machine:~$ tmux attach

And voila, just as you left it.

This is just a basic example. Things get more complicated with multiple sessions across multiple machines but hopefully this gets you started.