Engine keeps cutting off after new Coils have been installed (Not a Guzzi)

[MedicAndy]

It's not one of my 1100 Sport's that is causing me headaches right now, it's my 1996 1100 GSXR acting up........

Maybe some Guzzi's or Guzzi owners had this same issue with one of their bikes, and I hope that someone can give me some advice on what to check next?

I had some issues late last year with my bike running pretty bad, almost like she was only firing on one or two cylinders at times. Life happened, so she was sitting in the shop for about six month without starting her up. I finally had some time a couple of weeks ago, so I fired her up and rode her around my subdivision, and she did ok, but still skipping a little.

I removed the tank to check the plugs, since she has a set of Keihin 41 FCR's installed which are setup to run rich, and the plugs had carbon build up. I also noticed that the plug wires were loose on the coils, to the point that they just pulled right off from the coils cable ports.

I bought new coils via eBay and installed them this morning. I first started the bike up (still with her original coils and dirty plugs), and she fired up without any issues, but she was huffing and puffing a little, and she also smoked out of her pipes as I reffed the engine up. I let her run for about two minutes and then cut the engine off.

I then removed the old coils and plugs. I cleaned the old plugs, which only have around 1k miles on them, and I then reinstalled them. I also installed the new coils without any issues.

I then reinstalled the tank, plastic, and seats.

I hit the start button, and she fired right up. The engine burned the fuel clean and the exhaust fumes were colorless. The engine also sounded great.

However, the engine cut off after sitting at idle for about 40-50 seconds. I thought that I forgot to open the fuel valve again, but fuel was running to the carbs. I noticed the RPM's bouncing between 800 to 1k for about five seconds before the engine stalled. There was no huffing and puffing when the engine cut off. It was just like turning the engine off with the key or running out of gas.

The engine then would not restart. I would need to wait around five minutes before the engine would start up again, and the same would happen again and again...... the engine would run great for about a minute, and I was able to ref the engine up without any issues, but she would cut off again, and again, and again....... I opened up the carb bowls just to make sure that fuel was in the carbs, and all four bowls had fuel within them.

So I don't know what the issue is now...... I'm not really good working around bikes, but I can do general maintenance and repairs. I first thought that maybe the carbs are clogged from sitting for several month, but I only use ethanol free fuel with a marine stabilizer, so I like to think that the carbs are still clean / jets are not clogged? The engine was also running without cutting off before I replaced the coils........ But it just seems like that the engine is not getting any fuel, and it seems like that five minutes are needed to refill the carbs??????

Could the new coils have a defect which would trigger the engine to cut off after around a minute of running? I would think that a new coil would either be bad or good, but I don't know on how a "bad" "New" coil would act?

And cleaning the plugs cured the smoke coming out of the pipes....

Or did a pilot jet possibly decide to clog up on me? But would one bad jet cut the engine clean off, like it was turned off with the key, and this would happen right during the same time as me changing the coils out? I guess that stranger things have happened?

I'm a little lost now on what to do next, so any help is greatly appreciated. I can't reinstall the original coils, since all four cables have come off from them after I removed the coils from the frame. The carbs were just professionally cleaned and rebuild last year, so I really don't want to take them apart again. Should I start with buying a second new set of coils and see if this would fix the issue?

Andy

[lucian]

Did you accidentally pinch a fuel line when you re installed the tank? Sure sounds like fuel starvation, plugged filter or petcock screen? If all these check out I would be checking carb float levels. 

[fotoguzzi]

tank suck? is it venting?  did you replace the plug wires when you got the coils? you should.  are the coils really hot when it shuts down? are the coils the right ones for this bike?
I know nothing about GSXR's  is there 2 or 4 coils?

[rodekyll]

You can put a timing light on a spark plug wire to see if it's still sparking as it dies.

 If it keeps dying at the same point in time it's either the coils simultaneously overheating and crapping out at the same moment or it's starving for fuel.  I'm leaning toward fuel since an upstream fuel problem is more likely to affect all the cylinders at once.  Does this one have a vacuum fuel pump?  Next time it happens you could shut off the fuel valve immediately and check a float bowl. 

[MedicAndy]

tank suck? is it venting?  did you replace the plug wires when you got the coils? you should.  are the coils really hot when it shuts down? are the coils the right ones for this bike?
I know nothing about GSXR's  is there 2 or 4 coils?

Thanks for your reply,

The coils came with new wires already installed. I'm pretty sure that the coils are the correct ones for my bike. I did buy them viaeBay, but the seller specified the model years that the coils were compatible with, and it was for the 1992-1998 GSXR1100W model, and the coils looked identical to the coils I removed. And there are two coils with coil one firing cylinder 1&4, and coil # 2 firing cylinders 2&3. Neither the coils or the plug cables were hot when the bike shuts down.  I also opened the gas cap while the engine was running, so there was no vacuum being created, and the engine still died. The GSXR also has a special vent hose build in onto of the tank which I checked, and the vent is open.

[MedicAndy]

Did you accidentally pinch a fuel line when you re installed the tank? Sure sounds like fuel starvation, plugged filter or petcock screen? If all these check out I would be checking carb float levels.

I don't think that I pinched a line, but I did remove the tank and had it sitting up on the seat with both fuel lines exposed. I wanted to see if I had fuel in the lines and filters between the petcock and the carbs. The fuel lines and the filter were full of fuel while the bikes engine was running. But I did not pay attention to see if the fuel was actually flowing down the hose, or if it was just sitting there?

This is something that I'm going to check up on when Im off from work again this weekend.

Thanks for your reply,

Andy

[MedicAndy]

You can put a timing light on a spark plug wire to see if it's still sparking as it dies.

 If it keeps dying at the same point in time it's either the coils simultaneously overheating and crapping out at the same moment or it's starving for fuel.  I'm leaning toward fuel since an upstream fuel problem is more likely to affect all the cylinders at once.  Does this one have a vacuum fuel pump?  Next time it happens you could shut off the fuel valve immediately and check a float bowl.

I need to see if I can buy me a timing light to check for the spark. I looked at the different times that I kept up with, which was from the engine starting up to dying, and the times were between 50 seconds to around 90 seconds. No fuel pump, this bike has four inline Keihin 41mm FCR Flat Slide Racing Carbs with individual K&N filters.

I checked the carbs float bowls, and they all had fuel within them when I opened the drain plug, but the bike didn't start. Now thinking about it, I did twist the throttle open several times while trying to restart the engine, and I smelled fuel, it smelled like I flooded the carbs. But I also had fuel all over the place from opening the bowl drain plugs.....  The engine when running would also respond to every twist of the throttle. The engine didn't hesitate at all to get up into the 8k-10k rpm's ranges without any issues.

I will disconnect the fuel lines from the petcock this weekend to see if fuel actually is being sucked down the fuel lines and thru the filters. This would then tell me really fast if it is a fuel starving issue, or if I have possible issues with the new coils, since those coils were the only change I made besides cleaning the plugs.


Andy

[Tom H]

A quick way to check for spark when it's in it's no run condition is to have a spare known good spark plug and pull a wire off a plug and attach it to the known good plug and hold it against the engine. Try to start the bike and see if the plug sparks.

As a side note, plugs can spark while out of the bike and not spark under compression when installed. Something weak in the ignition system can cause this.

Caution, make sure you don't have a gas spill when you try this.

Good luck,
Tom

[flangeman_70]

Are you certain there isn’t a fuel pump?????
Sounds odd for a bike of the type carbs or EFI not to have a fuel pump.
In the carb version they run 2 speed which is determined by the ignition module.

Adam

[chuck peterson]

WIld Ass Guess....partially blocked fuel flow. Yes your getting gas, but not enough. Rust in the fuel tap?

[Two Checks]

If there is no spark on all cylinders check the  pickup coil or ignition module.

[rbond]

I worked on a Kawasaki with similar problem. Turned out to be the crank sensing coil would work until it got hot, let it cool down some, bike would run just fine. Then it would shut off,, engine would spin by the starter, but would not run. That coil does the job of points, telling the coils when to make sparks. Use a multi meter to check what the resistance is cold, start bike, run until it quits. Check coil again to see if no resistance or the same. If same, problem is elsewhere, if none, here is your problem.

[Sheepdog]

Is it a California model? Those had a bunch of piping in and around the tank that could contribute to your issues...

[MedicAndy]

Coil problem solved.......

The new coils are either bad or they are not meant to go onto a 1996 GSXR-1100.

I first checked the fuel supply going to the carbs, which was fine. I then uninstalled the new coils and re-installed the old coils, and the engine started up without cutting off again or having any other issues.

I bought this set of new coils and a new starter solenoid (which is a 20 amp and my bike needs a 30 amp), for this bike about a year ago, but I didn't have time until this week to actually install the items, so the eBay timeline to return the items has long expired.

So lesson learned the hard way! I won't assume anymore that the sellers knows, although having high ratings, that a part actually fits my application, and check my old parts first (starter solenoid) to make sure that they will actually match on what is being sold as a direct replacement. I'm also sure that the seller of the coils and solenoids would have replaced the items, if I had installed them when I bought them, so that was my bad!

Another problem with the coils is that the parts and packaging boxes are unidentified / unmarked as to what model or manufacturer they are, so I can't contact anybody to question the correctness of the coils to my bike.

Thanks for all of the great recommendations,

Andy

[rodekyll]

Thanks for the update.  When I said it was unlikely that both coils would fail at the same time, I was assuming they were the correct ones.  I'll add that to my list of things to check.

[fotoguzzi]

Hey, make contact with the seller.. I've found a few good businesses out there that would refund or replace even after the return by date. Especially if you give them the sob story about not getting around to fixing for so long.
can't hurt to try..

[Murray]

From distant memory these things had a vacuum driven fuel pump and activated tap that was prone to issues some of them had a "prime" setting might be worth seeing what happens if you run the bike on that or even check you are turning it on and not to prime. The other thing is the 41mm FCR the carb recommended for the bike? They are capable of massive flow and generally were uses on high performance single cylinder 500cc plus dirt bikes its possible they are too big when feeding a cylinder that's just over 250cc.

[MedicAndy]

From distant memory these things had a vacuum driven fuel pump and activated tap that was prone to issues some of them had a "prime" setting might be worth seeing what happens if you run the bike on that or even check you are turning it on and not to prime. The other thing is the 41mm FCR the carb recommended for the bike? They are capable of massive flow and generally were uses on high performance single cylinder 500cc plus dirt bikes its possible they are too big when feeding a cylinder that's just over 250cc.

The new coils were the issue.  And yes, those 41mm FCR's are very much oversized for this type of bike, but I absolutely love the way they sound and perform. To me, listening to those flat slides rattle at idle speed, and then synchronic into a fast almost turbo like whistling sound is intoxicating to me. But, not everybody likes the sounds that the slides make at idle. Some people actually asked be if I had engine problems....  My bike was, and still is somewhat setup for the drag strip. She was raced in her younger years at the Maryland International Raceway in the late 90's, and I bought her setup already with the FCR's from her owner two years ago. I almost pulled this $3k set of FCR's out of this bike, since this bike was a blast to ride at full throttle from 0-200, or at constant speeds over 70mph, but those carbs sucked down way too much fuel and constantly either flooded the carbs out and thereby barking her engine down at City speeds or just simply cut the engine off when sitting at a light. I found a local shop, and they with the help of Keihin / Sudco came up with a jetting setup which allows me to ride this bike now both at low and high rpm's. Needless to say, this bike will not see the drag strip again, and she definitely lost some mid and high rpm torque and top speed, but she still has around 180 hp, and this for a 22 year old bike is not too bad.

[Murray]

The new coils were the issue.  And yes, those 41mm FCR's are very much oversized for this type of bike, but I absolutely love the way they sound and perform. To me, listening to those flat slides rattle at idle speed, and then synchronic into a fast almost turbo like whistling sound is intoxicating to me. But, not everybody likes the sounds that the slides make at idle. Some people actually asked be if I had engine problems....  My bike was, and still is somewhat setup for the drag strip. She was raced in her younger years at the Maryland International Raceway in the late 90's, and I bought her setup already with the FCR's from her owner two years ago. I almost pulled this $3k set of FCR's out of this bike, since this bike was a blast to ride at full throttle from 0-200, or at constant speeds over 70mph, but those carbs sucked down way too much fuel and constantly either flooded the carbs out and thereby barking her engine down at City speeds or just simply cut the engine off when sitting at a light. I found a local shop, and they with the help of Keihin / Sudco came up with a jetting setup which allows me to ride this bike now both at low and high rpm's. Needless to say, this bike will not see the drag strip again, and she definitely lost some mid and high rpm torque and top speed, but she still has around 180 hp, and this for a 22 year old bike is not too bad.

We've covered it before but a set of 41mm's on an 1100 sport makes the world of difference.