How to change spark plugs

[El Paso Joe]

Hello,

I thought some of the information and pictures might be helpful to some. I've had my Street Triple since July of 08' and have put a little over 18,000 miles on it. I've kept up on the bike cosmetically and mechanically but I neglected changing the spark plugs.

Changing the spark plugs was very simple. I've never done a tutorial of any sort but hopefully what I write will suffice. If it doesn't, feel free to ask. It's best done in a garage to ensure no dust or anything goes into any ports. Unfortunately due to my living situation I had to do it next to my porch.

- First, empty tank of gas the best you can. I had less than two gallons of gas in my tank and a two gallon gas tank I keep in my car. I use a six foot hose used for windshield wipers and tucked one in to the bottom of the tank and the other to the gas tank on the floor. I sucked the bottom of the hose with my mouth barely and it started flowing into the tank.

- The gas tank is held on at two points. There are two screws in the front that you can visibly see from your seated position and a long bolt on the rear of the tank. Remove all three of them. The rear long bolt goes through a bushing sleeve that needs to be removed. Tap it out until a part of it shows and then remove it with some pliers.

Don't yank the tank off yet.

- Lift the now empty, and light, gas tank until you can see all the connections on the bottom of the tank. In total there are five:

2 small hoses for the overflow simply pull off.

2 electrical connections. You should see the tab you push in. Push it in and pull it away from tank for both.

1 fuel line to fuel injection (orange sleeve). You need to slide the orange sleeve down and then pull it from the tank.

Once those are all remove the tank should come right off.

- Next, you need to remove the air box. First take the top of the air box off by removing the outer screws. Once that is off and you have a visual of you intake and your air filter remove the seven screws I have labeled in my picture. I left all the electrical connection on top intact and hung the top off to the left because later I hang the bottom of the air box to the right.

- Before pulling on the air box you need to remove to vacuum hoses. One will be on the left side of the air box and the other will be to the rear of the air box (tiny). Once those are removed the air box will have one more vacuum hose on the right. Simply leave it intact. Remove the air box and move it to the right.

- The ignition plugs for the spark plugs have electrical clips on each one. Remove them and pull the plugs straight up to expose the chamber that goes to the spark plugs.

- Using a ball jointed socket helps here. I used a socket wrench and a six inch extension which was plenty.

Old plugs should come out fine. I used some spark plug grease on my threads and put the new ones in. To put everything back together it's all reverse of removal. Bike fired up on second try because the fuel hadn't gone all the way through yet. Bike sounds and runs great now. Please refer to my images and write me if you have any questions. When putting new plugs in the book calls for 13ft lbs torque (168 inch lbs)

I did this myself because the dealership I purchased my bike from wanted two hundred dollars to replace the plugs because they were "hard to get to". Start to finish took me about four hours.

[AaronP220R]

Very nice write up! Seems like a strait-forward easy process too!

[Diego]

Nice write-up overall, but I've got to caution against one thing: do NOT run the tank dry. Not to say it will cause a problem every time, but it has the potential to cause fueling errors and damage the catalytic converter.

Instead, simply remove the tank after the pressurization of the fuel system has had time to bleed down. It will not dribble much if you are reasonably careful.

[El Paso Joe]

Thank you.

I also did something I didn't mention in my write up but the springs and wire that open the throttle body are all in front of you when your changing the plugs. I cleaned them up with a q-tip and lubricated them and the throttle turn got a lot smoother.

Took the bike for a test ride today since I changed them yesterday. Bike seemed to start up better, idle better, and seemed to accelerate the way it did when I bought it. Could be my imagination though. Either way, very good day project when it's due.

[MacBandit]

Just to add to and to clarify what Diego said. There is no reason to drain the tank. The connector to the tank is a quick disconnect with a valve and will prevent leakage. Also to note about running a tank dry. As Diego said it's possible cause an error when the fuel get's low and the bike runs lean causing an O2 out of range error. The biggest problem though is that fuel pumps are cooled by the fuel they are immersed in. In my experience it's very very hard on fuel pumps to run the tank dry. I've replaced a lot of customers fuel pumps over the years and the most likely culprit was a common thread amongst the riders that ran there bikes out of fuel on occasion.

Also in my experience be very careful with lube around the throttle bodies especially on transverse motors where you can't clean them easily. The lube can cause multiple problems. The biggest problem is it tends to collect dirt causing throttle problems requiring teardown to clean. Other issues depend on the lube used. Some lubes are corrosive to rubber o-rings and seals and finally some lubes (silicone based especially) if they leach into the intake system and go through the motor will pollute the O2 sensor causing it to fail.

[Diego]

Originally Posted by MacBandit

In my experience it's very very hard on fuel pumps to run the tank dry.

Ah yes. I knew there was another reason, but I couldn't remember at the time what it was. Thanks for the additional clarification.

[El Paso Joe]

Learn something new every day.

I updated it just including how I drained it with a hose first in-case people use this source but don't look down the thread.

[RICHW]

I've got a Hinkley twin, so it's much easier to access the plugs, however, I could use some input from you all on this:

After washing my Bonnie on Sunday, I ran the engine for a few minutes afterwards. What I saw during that time was this:

My left side’s cylinder was “bubbling” a little where the water was – all around where the spark plug is seated. Also notable – the right side’s plug didn’t bubble at all.

I recently (a month ago) took the plugs out to check the gap and clean them, and I’m wondering if I should have replaced the “crush washer” on them then.

Should I drop a new set of plugs in? Or, just put some spark plug grease around the threads?

[MacBandit]

I would just make sure the spark plugs are still torqued to spec. Sometimes (well actually frequently) after washing the remaining water retain other residues that will cause the water to foam as it boils off. This was a frequent occurrence in BMW twins where the cylinders are on the sides and would trap water and other residues.

[TwoWheeledFan]

Thanks to El Paso Joe, MacBandit, and Diego.
Having ridden Jap bikes all my life, I enjoyed doing benign maintenance on them while being reassured by the likes of Clymer or Haynes manuals. It was only after purchasing my ST3 that I discovered that there didn't appeared to be any such offering for Triumphs.

I am glad there's people like you to fill in the gap (mind the gap ).

Thanks again.