Carbs, Coils, Valves oh my!

[cousindave]

So I really hate to create a new thread on this beat down topic but have not been able to resolve my issue.

   Bike: 95 Steamer, 40K+, black(that's important :D )

   Problem: I was ridding to work last week and just before I got to my office I suddenly lost all power and it would barely run. It stalled and I pushed into driveway. After much fiddling, got it started and found cyl's 2 and 3 are not firing. Any throttle at all makes a sucking sound through the snorkel followed by immediate stall.

   I tried the obvious first. Checked the fuel supply and filter. Nothing. I changed the spark plugs(old ones looked fine), no change. After reading about every post on this board about the symptoms, I decided to pull and clean the carbs. I found nothing but the utmost spotlessly clean carbs. I cleaned anyway and reinstalled air tight with all the snorkles and everything, no change. After reading every post on coils I could find, I started suspecting coils. I can't ohm test the coils but I knew cyl #1 was firing so I plugged cyl#2 into coil 1 and changed the wires too. Now cyl#2 was the only one firing. Ah Hah! Coils right? That's what I thought. I just replaced them with three new Nology coils. Problem persists. Now I'm lost. I know the valves being out of adjustment can cause problems but I have not suspected the clearances as a problem because of how fast the problem came on(instant). Can the valves do that? I'm lost otherwise. I looked into the pickup coil as the problem but the symptoms I have found on this board do not match mine.

Please let me know if there is something I'm over looking here.

[Mustang]

I found nothing but the utmost spotlessly clean carbs. I cleaned anyway and reinstalled air tight with all the snorkles and everything, no change.

Are you positive the pilot jets are open ....can you see thru the little bitty hole that is in them ?

I knew cyl #1 was firing so I plugged cyl#2 into coil 1 and changed the wires too. Now cyl#2 was the only one firing. Ah Hah! Coils right? That's what I thought. I just replaced them with three new Nology coils. Problem persists. Now I'm lost. I know the valves being out of adjustment can cause problems but I have not suspected the clearances as a problem because of how fast the problem came on(instant). Can the valves do that? I'm lost otherwise. I looked into the pickup coil as the problem but the symptoms I have found on this board do not match mine.

Please let me know if there is something I'm over looking here.

this makes no sense if you swapped coils and the running cylinder was the dead one now and vice versa
are you positive you have the coils hooked up correctly
ie coil #3 is yellow / brown wire
coil 2 is yellow wire
coil #1 is green wire

and if your coils are good you should be able to verify spark by hooking a plug to each plug wire and ground the plug to the frame or engine and see it spark

is your tank vent good ? see if the bike will run alright with the gas cap open

and you probably do need to verify valve clearances just to know whether they are good or not
zero clearance on the intakes will cause nothing but problems

[cousindave]

Are you positive the pilot jets are open ....can you see thru the little bitty hole that is in them ?

Mustang to tell the truth, I took the carbs off three times thinking I must have missed some spec of something. But yes, I can see through the holes on the main jets and pilot jets. I used carb cleaner on the jets and the carb bodies just to be sure I'm not missing something I can't see. The PO had the carbs completely rebuilt about 3000 miles ago. It's been on the street only and has a new airbox and air cleaner on it. So I'm not that surprised that the carbs were nice and clean.

this makes no sense if you swapped coils and the running cylinder was the dead one now and vice versa
are you positive you have the coils hooked up correctly
ie coil #3 is yellow / brown wire
coil 2 is yellow wire
coil #1 is green wire

No sense indeed! That's why I'm lost on this one. It's like the bike only has enough electrical power to keep up with one cylinder at a time. I did take the plugs out and rest them on the block. All the plugs sparked. With the old coils the spark was not impressive so I still thought that bad coils could be the problem. I've not tried that test with the new nology coils to compare.

I'll try the gas cap test. I've not tried to run it with it open but I have had it open just to have a look for junk and other fuel related problems. Tank is nice and clean. I'll check that one out.

My valves do need to be checked for clearances, but can two cylinders go dead at the same time due to valve clearance? And the fact that I can bring the cylinder back to life by making it the only running coil would not point me to valves. Right?

I'll keep poking around and experimenting. Man I'm depressed!

[rf9rider]

A friend of mine had the same symptoms you described on his FZR1000 Exup.
After 12 months of testing plugs, leads, coils, carbs, and everything else anybody could think of,it turned out his wiring loom was faulty.
Maybe something to look at
 :idea:

[nightrunner]

He's got three new Nology coils so its hard to imagine two are bad.  What about the ignition pulse sensor?

PS.  Don't worry about checking ohms on your coils.  Most only fail under a load and still ohm out just fine.

[harre]

Just a thought.
I once had a similar experience. Drained the carbs into a glass jar and saw two phases separating. It turned out that I had water entering the tank through the fuel cap. You have already drained the carbs, but you can also drain the the tank into a glass jar and look for phase separation.

[cousindave]

So I'm frustrated... surprise huh? Ok, I had a chance to do a few things today and thought it's time to sit down, have a beer and let you guys know what's going on.

I pulled the valve cover today to check clearances. Once off I discovered my feeler gauge does not go down to .15mm. I did note however that all shim buckets freely spin. So at the least I know there are no valves operating to tight. Also, the gasket looks very new, as if the PO had the valves checked only a few thousand miles ago. So for now I'm not looking at the valves as a problem.

I pulled all the plugs and checked for spark. All three were sparking and the number 3 plug was dry. It simply MUST be a fuel problem, right? So off with the carbs for the 4th time! I took the carbs home and very calmly and meticulously took all jets and needles out and soaked them in carb cleaner. Drenched the carb bodies with carb cleaner too. Blew everything out with air and looked through all jets and saw plainly that there are no clogs. I checked float hight and needle operation. Perfect. Diaphragms are perfect. Fuel filter is clean as a whistle. I set pilot needles to 2.25 turns out. My point here is, the carbs are in perfect shape. Nothing more I know to do to them.

Next I checked the pickup coil. It ohmed out at 543ohms. According to the manual, that's in spec. The gap was on the high side right at .8mm. I adjusted it down to about .65mm.

And now for the test run!

I fired it up with full choke and was immediately greeted with all three cylinders running at 3500rmp. It was a smooth idle and excited me very much. BUT... yeah you knew that was coming... ...when I start to spin the throttle I get good response and then right at this very exact position the carbs suck air and the engine completely stalls. I let off while I still have some RMP's and it starts to idle again. over and over the same thing happens. Even if I slowly bring the throttle up it hits a brick wall at about 4500-5000 rpm and completely stalls out. As it warmed up it got worse and worse and eventually got down to running on cylinder 1 again until it just wouldn't run any more.

Any ideas?

Pickup coil is my only thought now but unlike the experience of others, when this happens I don't loose my tac, and it does not just go from running strong to stalling. It just slowly dies out at it warms up.

Help!

I'll start it up again in the morning and see if the same cycle happens. I'll let you guys know the outcome.

[cousindave]

Just a thought.
I once had a similar experience. Drained the carbs into a glass jar and saw two phases separating. It turned out that I had water entering the tank through the fuel cap. You have already drained the carbs, but you can also drain the the tank into a glass jar and look for phase separation.

I added gas Harre but did not think to check for water. I'll drain some fuel from the tank tomorrow and see what I get.

[nightrunner]

So something is working cold and fails as it warms up.  I wonder if plug wires could be the problem.  Carbon core wires are not like simple copper conductors.  They can change with heat.

Maybe you've done this but how about after it warms up and fails (and you still have one cylinder working) swap the coil from the good cyl to another spot and see which plug fires then.  Then do the same with the wire from the good cyl.

As you said the pick up would knock them all out.  Also it would not consistent leave the same cylinder working.  I'm assuming its the same cylinder that remains working(?)

One note about your report though...if I read it right.  I would not  expect a cold engine to rev very high when you first fire it up.  I wouldn't even want to try.  

And yes the water in the tank is a good thought too.  I would pull the tank and turn it so all the gas flows to the left side and drains out.  Could be trapped water just barely at the level of the petcock tube.

[cousindave]

Maybe you've done this but how about after it warms up and fails (and you still have one cylinder working) swap the coil from the good cyl to another spot and see which plug fires then.  Then do the same with the wire from the good cyl.

   I did try that with the coils before I replaced them with the Nology coils. I managed to move my running cylinder from #1 to #2. I have not tried that since the new coils(since I can be pretty sure they are all good) and I have not tried swapping plug wires. I'll do both today and see what results.

As you said the pick up would knock them all out.  Also it would not consistent leave the same cylinder working.  I'm assuming its the same cylinder that remains working(?)

Yup, cylinder #1 is always the one left running.

One note about your report though...if I read it right.  I would not  expect a cold engine to rev very high when you first fire it up.  I wouldn't even want to try.

   It rev's to about 3000rpm because of having the choke fully pulled for cold  startup. It has always done that since I have had the bike. Is that a problem? Wrong? With the choke returned to normal warm operating position the idle goes back to about 1000rpm. I found that my throttle had the same movement restriction at any rpm range. If I pull it to much it makes that sound of sucking air through the snorkel followed by immediate stall out.

And yes the water in the tank is a good thought too.  I would pull the tank and turn it so all the gas flows to the left side and drains out.  Could be trapped water just barely at the level of the petcock tube.

   I'll be trying this today.

Thanks Nightrunner for all your input!

[cousindave]

Harre if I was near you I would kiss you...  ermmm... well, shake your hand. So I have once again proven that the best way to fix something is to sit down and have a drink and think... aaaand have a couple more drinks or few.

I drained some fuel into a glass container as you suggested, Harre and sure enough it settled out at about 50/50 water/fuel. Wow! I can't tell you how happy I was to find that! I drained the rest of the tank and drained the carbs and filled up with fresh premo fuel. Presto, it started up and runs awesome! And because of this experience, I cleaned my carbs 4 times, synced my carbs, checked my valves, checked my pickup coil and installed new Nology coils. So, now it runs better than ever!

Mustang, I'm sure you wrote me off knowing I was missing something easy. Thanks for your valuable input. Your contribution to this board has helped me so many times! Most of the time I never have to start a new thread because somewhere along the way you have already answered the problem. Kudos!

Thank you guys for all the input. It's always something easy but we always make it hard.   :lol:

[coachgeo]

Glad to hear your got her breathing fire like she should be!

[rf9rider]

Good news, now time  to check where the water got in  :lol:

[harre]

cousindave, no need for... I'll settle for that handshake. I'm happy that I could help you. Your bike must be in perfect condition now. Those coils would have let you down sooner or later.
I remember the feeling when I saw the two phases separating. These hard-to-find but easily fixed problems are the best! For me I solved the problem the evening before a long trip to Norway with some friends. Don't really know how that much water could enter the tank though but it had been raining a couple of days. It is easy to check this whenever the engine starts to run badly. Maybe this is more common that people think. On a previous occasion the engine was hesitating but suddenly started to run like is was on steroids, I think that was when the water finally was gone.

[Mustang]

now clean out the drain hole on the tank to keep from getting more water in the tank

on the bottom of tank there is a hose nipple screwed into the tank (bottom right rear corner )
unscrew it and seee what comes out for debris that is usually where they get blocked and then when it rains the water backs up the pipe which exits at the top of tank under the gas cap . with no where else to go it runs into the tank