[Mance]

Hi Fellas,

I'm a new RE owner, and this is my first post.  I'm glad to be a part of the club, and I love the bike.

I have a 2009 Military (C5 / UCE / EFI).  The bike has approximately 4300 miles on it, and I've only had a few minor problems: bad battery (twice), replaced chain at 4000 miles, and now I'm having a performance issue.

The bike misfires and backfires.   Sometimes it is REALLY bad.  I worried that I wouldn't make it to my house 2 miles away a couple of days ago.  Sometimes it doesn't happen at all.  I took an hour ride yesterday, wound out the bike and it performed perfectly.  Today it is working perfectly.

Related Notes:

1) The exhaust pipe has heavy bluing.  (Maybe the engine is running lean?)
2) I can't see a substantial difference with temperature, but the problems only started this summer, and the weather in Texas is always warm.
3) In the past couple of days, when bike has worked well, there is a strong smell of gasoline.  That is new and unusual.  Smells like it is running rich.

Here are the possibilities I can think of:

1) One of the sensors used for EFI is going bad.
2) There is a vacuum leak either in air intake or with the exhaust that gets seeled up when the engine heats up.
3) The bike just takes a while to warm up, and it is going to misfire / backfire until it does.  But that isn't normal for EFI?  Correct?  And this didn't start until around 3000 miles.

Any ideas?  What could make the system suddenly go from running lean to running rich?  Or could the symptoms be caused by something else?

Thanks

Mance

[singhg5]

Hi Fellas,

I'm a new RE owner, and this is my first post.  I'm glad to be a part of the club, and I love the bike.  I have a 2009 Military (C5 / UCE / EFI).  The bike has approximately 4300 miles on it, and I've only had a few minor problems: bad battery (twice), replaced chain at 4000 miles, and now I'm having a performance issue.

The bike misfires and backfires.   Sometimes it is REALLY bad.  I worried that I wouldn't make it to my house 2 miles away a couple of days ago.  Sometimes it doesn't happen at all.  

Mance:

Welcome.  The engine can backfire and misfire due to many reasons, as you have pointed out - including problems with spark, fuel/air supply, or compression.
 
Start by checking the simplest things.  Spark plug - is it worn out or ok ? Put a new spark plug and see if it improves.  The intermittent occurance suggests that there may be a loose electric connection.  Is the spark plug cable connected firmly into the spark plug and to ignition coil ?  Look for any air leaks in intake manifold.  A dirty or clogged fuel injector may also contribute to misfire or backfire.  

The bike runs lean by default.  I guess that if any EFI sensor was bad, the Malfunction Indicator Light would come on.  

[Mance]

Thanks for the note.

Yes, I forgot to mention that I changed the spark plug.  Replaced with stock equivalent.  I don't have any experience looking at plugs to tell if the bike is running lean or rich, so I can't say much about how the old plug looked.

I wondered about the fuel intejector.   At its worst, it felt like the fuel line was clogged somewhere.  Almost impossible to keep the bike running.  However, a storm had just passed through, and the temp dropped 20 degrees.  No idea how / if that affects EFI on this bike.

The spark plug cable is connected firmly at the plug, but I haven't checked it at the coil.  Will do.

I'm not a mechanic, but I want to learn how to maintain this bike on my own.  Outside of visually inspecting the air intake, is there something else I should do to check for air leaks?

Mance

[Mance]

Whoa!! Major problem.  The reason I started the bike smells like it is burning very rich is that the fuel tank is actually leaking gas!  Near the rear bolts on the left side where there is a welded seam, gas is oozing from the tank.

I assume that something from the tank actually broke lose and made it into the gas line a few days back when the engine was running at its worst.  The performance of the engine has been great for the past two days.

I guess this calls for a trip to the dealer in the morning.

Mance

[prof_stack]

Whoa!! Major problem.  The reason I started the bike smells like it is burning very rich is that the fuel tank is actually leaking gas!  Near the rear bolts on the left side where there is a welded seam, gas is oozing from the tank.

I assume that something from the tank actually broke lose and made it into the gas line a few days back when the engine was running at its worst.  The performance of the engine has been great for the past two days.

I guess this calls for a trip to the dealer in the morning.
Mance

Yes, it does.  Let us know how it goes.

[singhg5]

Thanks for the note.

Yes, I forgot to mention that I changed the spark plug.  Replaced with stock equivalent.  I don't have any experience looking at plugs to tell if the bike is running lean or rich, so I can't say much about how the old plug looked.

The electrode of too rich spark plug will turn black due to unburnt carbon deposits and too lean spark plug electrode will be whitish.

You found the leak from the tank.  Sure it is time to see the dealer.  

[Mance]

Will do.  After doing a little more research, it looks like a few others have had problems with rust inside the tank leading to pinhole leaks.  But most of those are on older bikes. 

Rust would probably explain the sporadic misfires and poor performance of the engine, but this bike is less than a year old, so I am surprised.  I don't always keep the tank full, but I ride it daily and fill up frequently.

If it turns out to be rust in the tank (and it sure looks like a pinhole leak at the welding seam), then we can add another possible cause to the standard list of misfire / backfire / performance problems.

Mance

[singhg5]

Thanks for the note.
I don't have any experience looking at plugs to tell if the bike is running lean or rich, so I can't say much about how the old plug looked.

Here is a reference picture of what a spark plug looks like under different conditions -

[Mance]

Wow.  That is a great reference.  Thanks.  It will get printed and put on the garage wall.

I took the bike to the dealer today.  He doesn't believe there is rust in the tank, but rather believes that the joint where the tank gets bolted to the chassis just isn't holding up from the vibrations.  After the tank is replaced, he plans to put some kind of dampener around the bolt.

Regarding the sporadic performance, he has heard some people speculate that the catalytic converter isn't getting hot enough on short trips.  As a result, gunk builds up and causes problems.  After I ran the bike hard for 30 minutes earlier this week, the symptoms did go away.   On average, I ride the bike only 5 minutes at a time, and the engine never really gets that hot.  So maybe it is the CC.

More to come.

Mance

[Vince]

     Riding the bike 5 minutes at a time is the cause of most of your issues, including the battery. It takes about 1/2 hour of normal running to recharge a normal battery from one normal starting attempt. Your riding habits run the battery down. The ignition system runs off the battery. The charging system charges the battery. Low battery=weak ignition/injection=poor running="defective battery". Even with F.I. you will not get proper burn/combustion until the engine is warm.
     You should change your riding habits. Ride more and longer.

[2bikebill]

"Ride more and longer"

music to my ears.......   

[1 Thump]

     
     You should change your riding habits. Ride more and longer.

I like that .

[1Blackwolf1]

  Should also install a battery tender to keep it charged up if you can't ride it for long distances.  Cost is generally less than 30 bucks and will eliminate lots of problems.

[prof_stack]

  Should also install a battery tender to keep it charged up if you can't ride it for long distances.  Cost is generally less than 30 bucks and will eliminate lots of problems.

+1 

The Battery Tender will pay for itself after one year.  I think all new Enfields come with a connector installed.  Mine did and it is on the bike in the garage all the time.

[Geirskogul]

No, the connector is a dealer special.  Mine didn't have one.

[r80rt]

Mine didn't have one either, but it does now!

[Mance]

Well, it looks like that was the issue.  After talking to the dealer, he said that the EFI system runs rich in the first two minutes of use.  After that, it settles into a normal mix.  However, most of my rides have been abut 5-8 minutes, which means that a significant portion of my ride is running rich, and subsequently fowled the plug.  I had the biked serviced a few weeks ago, and a brand new plug had already gone bad.

The low battery contributed to the ignition problems.

Also, apparently there have been problems with the fuel tanks.  The distributor has ordered a batch from India because of the demand.  But RE is taking care of the problem.  They are paying for a liner in my existing tank and will also replace it when the new tanks arrive.

I guess you could say that my bike and I are getting acquainted.   

Mance

[Kevin Mahoney]

Coming into this a bit late. The EFI is not under full control until the O2 sensor heats up. it is the ugly device bolted to the exhaust pipe. It has a heater element in it, but it takes a minute or two for it to fully kick in. When it does kick in, it tells the ECU (brain) exactly how much O2 is in the exhaust which allows the ECU to compensate for the perfect mixture. Before it kicks in the ECU has to run rich to keep things moving. When you start the bike cold you may want to use what looks like a decompressor on the left handle bar. It enrichens the mixture like a choke. As soon as the sensor kicks in moving it has no effect.

Long story short, start stop stop start will foul the plug. We are having some trouble in some cities in Switzerland with this issue. Apparently you have to turn off your bike at every stoplight. They are fouling plugs like crazy.

[clamp]

Obviousl;y the engine management control is not sufficient, ie insufficient information feeding the control unit.

    I knew it --they should not have ended the 350 iron with a carb on it until they had it sorted .

     I dont care id they do.-- I still dont want EFI   well not RE indian anyway.

[tomselwyndavis]

Hello,

Also coming to this a bit late. Bought a beautiful black classic after riding one 2500km across the Indian Himalayas and instantly fell in love. However I too am having this problem, My bike has a shorter non stock exhaust (sounds fantastic) and was riding fine for about 500 miles until the exact problems that Mance listed started happening on my daily commute in London. For the first 2-3 miles the bike is almost un-ridable, popping, backfiring and setting off every car alarm I drive past but if I stick with it the bike starts to ride beautifully, (smells a little hot though) Mance did you eventually solve this problem without having to turn it off at every traffic light? Also getting tired of having to buy a new spark plug every 2 weeks!

Many thanks!

 

[Mr.Mazza]

Hello,

Also coming to this a bit late. Bought a beautiful black classic after riding one 2500km across the Indian Himalayas and instantly fell in love. However I too am having this problem, My bike has a shorter non stock exhaust (sounds fantastic) and was riding fine for about 500 miles until the exact problems that Mance listed started happening on my daily commute in London. For the first 2-3 miles the bike is almost un-ridable, popping, backfiring and setting off every car alarm I drive past but if I stick with it the bike starts to ride beautifully, (smells a little hot though) Mance did you eventually solve this problem without having to turn it off at every traffic light? Also getting tired of having to buy a new spark plug every 2 weeks!

Many thanks!

 

My suggestion would be to, walk up to your bike,start it. THEN go put your gear on and prepare for your trip.
5 mins later everything is settled and it should have a smooth ride all day.
This allows all the EFI system to start up taking readings and all that.
Also helps oil bathe everything before any load is on the engine.

[gashousegorilla]

Hello,

Also coming to this a bit late. Bought a beautiful black classic after riding one 2500km across the Indian Himalayas and instantly fell in love. However I too am having this problem, My bike has a shorter non stock exhaust (sounds fantastic) and was riding fine for about 500 miles until the exact problems that Mance listed started happening on my daily commute in London. For the first 2-3 miles the bike is almost un-ridable, popping, backfiring and setting off every car alarm I drive past but if I stick with it the bike starts to ride beautifully, (smells a little hot though) Mance did you eventually solve this problem without having to turn it off at every traffic light? Also getting tired of having to buy a new spark plug every 2 weeks!

Many thanks!

 

   + 1  to longer warm up period and use of the Bi-starter when it is cold and damp out.  Also, the  shorter , freer flowing exhaust may be a bit of a contributing factor while the bike is still cold and running a fixed map before it goes into closed loop..... with all that popping and backfiring. 

  That fuel has to easily vaporize , and it doesn't when cold .  The bi-starter helps it to.  Cold fuel in a cold engine causes an inefficient burn which also causes carbon .... a byproduct of incomplete combustion.... fouling your plug.  That inefficient burn is one thing at idle until it warms up and the ECU can take over..... but when you hop right on the bike and take off, working that throttle and spraying more cold fuel into a cold engine until the ECU can take over ....   

[jameswilkinson]

Hi all!

Thanks for all your tips. To let you know. I took the head off and it was the piston that had shattered. I have bought a new one and am in the midst of replacing the old one.

There are quite a few shards of the metal including bits of broken piston ring that have however come and are swimming in the sump. Ive bought an extendible magnet which has managed to pick up a fair bit of the metal however I was wondering if anyone had any other techniques for getting the metal shards out. Perhaps I could drain them out? or rinse them out with water?

Any tips again much appreciated. Hopefully can do the fix for < £100

cheers all!