Throttle issues - Bike wants to die

[broilmebk]

So at almost 17k miles, I've finally ran in to a technical issue. I think I've got it figured out, I just wanted to get corroboration I guess and some help on the repair.
(I did 15k maintenance at about 15.2 and no problems up until now)


TL;DR: Rode in pouring rain. Smoke from radiator area and burning smell. Bike runs fine till just about home when idle drops. Started bike 24 hours later just fine. Start moving, bike wants to die. Suspected water contamination. Pull left spark plug boot, notice condensation. Dry the well and boot. Pull right boot, notice damage. Who/what is real culprit? How to replace boot?


Yesterday in OC it rained quite a bit. I had no choice but to ride about 30 miles round trip. Close to my destination I picked up a smell of something burning and noticed smoke coming from the radiator area up through the forks. I was in a big hurry, distraught, and almost there so I ignored it (since the bike was still running fine). Upon leaving, bike started up fine. Couple stop lights later noticed the smell and smoke. Next light it diminished. Last light before home, idle wants to drop so I put the choke on and continued home. Went to ride it 24 hours later and started fine. Pulled out of garage and started to go but biked hesitates, rpms go up but suddenly drops and wants to die. I figured all that rain forced some water in somewhere. I didn't want to believe it got in the gas tank, and a friend didn't think it was either. He told me to pull the spark plug boots out and check for water. I noticed condensation on the left boot so we figured there was water in the well. I stuffed the well with paper towels and also used a can of compressed air to dry it out best i could. Pulled the right boot, didn't see any condensation, but did the same thing anyway. I also blew some air in the boot, and that's when I noticed one looked different from the other. Looks like the right one got damaged; not sure if it happened when I tried taking it out or some other reason. FWIW, there was a lot of FOD/gunk in the damaged boot.

So, definitely water got in somewhere. Would it in the spark plug well alone cause the original problem and I ended up damaging the boot when taking it out? Thoughts?
Clearly, I need a new boot/cap. Looks like part#21160. How do I go about replacing just this part? Is it a simple remove old boot, attach new one?

[Motofool]

The shape of the boot does not matter, as it could have been replaced before.
Your engine, however, needs a good electrical connection between that cable coming from the ignition coil and the tip of the spark plug.
There is a lateral hole for the well of the plug to drain any water out; the one for the affected boot may be clogged.

[broilmebk]

Oh, I wasn't referring to the shape/form/material of the boot, but rather what's inside it. The left has what looks like a gold connection, while the right does not. All I see is the blue. I figured it was supposed to look like the one on the left?
When I tried blowing air in the well I did not feel or see anything come out. Any advice? Can you point out this hole so I can try and unplug it?

[DaBlue1]

The smoke and burning you see and smell is water and road grime being burned off the exhaust and radiator.

The inside of the boot could have a little corrosion in it. Some battery terminal cleaner and some wiping should take care of it. Make sure it is (boot) dried good before reattaching. If you are going to be riding in or the bike sits in the rain apply some spark plug boot grease/ dielectric grease or some vaseline to the inside of the boot (also battery and coil terminals). This will help make a barrier/seal against corrosion and moisture. Also make sure that the plugs are good as well. Always ensure a good snug fit of the boot on the plug. It should not have any gaps.

There are two tiny holes underneath each exhaust manifold. They are the drains for the spark plug wells. Just make sure they are not clogged up with road dirt and grime.

Also keep in mind that with high humidity (rain, fog, dew) and a temp drop the warm idle speed may need a little adjusting. Always check your airbox and air filter for any condensation/water as well. Given the past history of many bikes on this forum that have sat in the rain, it is not uncommon for some water to end up in the tank or carb bowls. If after you take care of the other issues and you still have a problem, Draining the tank or fuel bowls and adding some fresh gas to the tank seems to always work. I also recommend Star Tron Fuel Treatment too. Best stuff I've used to combat dirty carb and ethanol issues.

Replacing the spark plug boot is easy. Just follow the leads back to the coils and connect them (new) the same way you take off the old ones. As with all electrical work, make sure you disconnect the battery before you do it.

[jkv45]

Replace the plug cap and see what it does. It looks like it was not attached to to the plug properly and had been arcing for a while.

[broilmebk]

Originally Posted by DaBlue1

The smoke and burning you see and smell is water and road grime being burned off the exhaust and radiator.

The inside of the boot could have a little corrosion in it. Some battery terminal cleaner and some wiping should take care of it. Make sure it is (boot) dried good before reattaching. If you are going to be riding in or the bike sits in the rain apply some spark plug boot grease/ dielectric grease or some vaseline to the inside of the boot (also battery and coil terminals). This will help make a barrier/seal against corrosion and moisture. Also make sure that the plugs are good as well. Always ensure a good snug fit of the boot on the plug. It should not have any gaps.

There are two tiny holes underneath each exhaust manifold. They are the drains for the spark plug wells. Just make sure they are not clogged up with road dirt and grime.

Also keep in mind that with high humidity (rain, fog, dew) and a temp drop the warm idle speed may need a little adjusting. Always check your airbox and air filter for any condensation/water as well. Given the past history of many bikes on this forum that have sat in the rain, it is not uncommon for some water to end up in the tank or carb bowls. If after you take care of the other issues and you still have a problem, Draining the tank or fuel bowls and adding some fresh gas to the tank seems to always work. I also recommend Star Tron Fuel Treatment too. Best stuff I've used to combat dirty carb and ethanol issues.

Replacing the spark plug boot is easy. Just follow the leads back to the coils and connect them (new) the same way you take off the old ones. As with all electrical work, make sure you disconnect the battery before you do it.

My airbox was dry. Both boots were installed as far down as they go. I will pull the plugs and check those when I get a chance. When I put everything back together I'll try to add some dielectric grease.
I checked for the holes this morning and I couldn't find any clogging.
When I was checking for parts, all I saw was the cap, no wire/lead. This led me to believe I'd have to somehow detach the wire from the cap and replace it, but it looked like one whole piece on the bike.

Originally Posted by jkv45

Replace the plug cap and see what it does. It looks like it was not attached to to the plug properly and had been arcing for a while.

Nobody is really confirming that this boot is actually damaged so I think I'm going to test for a spark first (unless someone can just save me a step). I'll pull the plugs and make sure everything is dry too. If it doesn't run smoothly after all this I'll try draining the tank and bowls and maybe using some star tron.

Have a busy day today so not sure when I can start troubleshooting. Thanks for the advice, will update when I can.

[broilmebk]

Originally Posted by Motofool

The shape of the boot does not matter, as it could have been replaced before.
Your engine, however, needs a good electrical connection between that cable coming from the ignition coil and the tip of the spark plug.
There is a lateral hole for the well of the plug to drain any water out; the one for the affected boot may be clogged.

Sorry Hernan. I thought you were referring to the rubber being different; I'm also the original owner so it didn't make sense that it was replaced. But after taking a quick look during lunch break I realized the connection is still there. I pulled the plug and it 'snapped' in to place in the boot as it does with the left one.

I have a strong feeling it's going to be water somewhere, so I'll end up draining the tank and bowls. Is there anywhere else I should be draining?
Before I do that, I'd like to test the spark plug to make sure it's firing. What is the exact procedure? I was going to have the boot and plug out, ground the plug via jumper wire and hit the starter. Should I have the well covered or plugged somehow? Any other precautions?

[Motofool]

Originally Posted by broilmebk

Sorry Hernan........Is there anywhere else I should be draining?
Before I do that, I'd like to test the spark plug to make sure it's firing. What is the exact procedure? I was going to have the boot and plug out, ground the plug via jumper wire and hit the starter. Should I have the well covered or plugged somehow? Any other precautions?

No need to be sorry, clean electrical contacts is what is important there.
No Brian, there is nothing else to drain.

Just keep the metal portion of the spark against any metal naked surface and crank it.
No need to plug anything.
Be careful of not touching the spark while doing that, so the electrical discharge does not go through your hand (painful experience).

[broilmebk]

Plug fired no problem. Cap wasn't damaged.
Drained the bowls and saw the water in the container. Started up fine, idled fine, no throttle issues. Threw in some seafoam as well. The left bowl was impossible for me to drain with a regular hex key. Had to get a bit and use a socket extension.
Thanks for the support guys.

[jkv45]

Originally Posted by broilmebk

Plug fired no problem. Cap wasn't damaged.
Drained the bowls and saw the water in the container. Started up fine, idled fine, no throttle issues. Threw in some seafoam as well. The left bowl was impossible for me to drain with a regular hex key. Had to get a bit and use a socket extension.
Thanks for the support guys.

Good to hear it's running again.

I still don't like the look of the contacts on that cap, but...

[broilmebk]

Thanks Jay. I cleaned it out and push it down as far as it would go. The gunk seemed like some sort of grease. I'll pull them out some time later to check on them.

[jkv45]

Originally Posted by broilmebk

Thanks Jay. I cleaned it out and push it down as far as it would go. The gunk seemed like some sort of grease. I'll pull them out some time later to check on them.

If it's the proper kind of grease - dielectric grease - you are fine. If someone used regular grease it should be removed. Take a Q-tip and some brake or electrical cleaner and remove it.

If the contacts are bright and shiny when you do you are fine, if they are dull, black, or pitted (what they looked like to me from the photo) I'd replace the cap.

[Motofool]

Originally Posted by broilmebk

Plug fired no problem. Cap wasn't damaged.
Drained the bowls and saw the water in the container. Started up fine, idled fine, no throttle issues. Threw in some seafoam as well. The left bowl was impossible for me to drain with a regular hex key. Had to get a bit and use a socket extension.
Thanks for the support guys.

You are welcome

http://en.wikipedia.org/wiki/Silicon...lectric_grease