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TOPIC: Re:Firing on one cylinder
#1020048
SKWEARpeg (User)
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Re:Firing on one cylinder 1 Month ago  
Shores wrote:
Is SVS not a possible cause?


Highly unlikely with the bike being a 1600. It was a 1700 demon. Although it resulted from the valve guides not having enough clearance in the 05's(ish), it was also pretty much related to jetting,... IMHO.
IMHO,....The 1700's were jetted to lean from the factory in the Pilot circuit, which resulted in bumping into the Main to much while at cruise(a sloppy transition), and caused the rich situations. Add in these bikes being cruisers, and many riders not wringing them out enough but doing to much putt-ing around(5th gear at 40), and the Carbon build up in the heads cropped up. If your asking for a wee bit more speed, and the Pilots to small you open the throttle a bit before the rpms are up enough for good air flow through the venturi. The fuel slobbers into the throat around the needle, instead of whoosshing in with the rush of air needed for good atomization.
This is why people could go to a 40 Mikuni Pilot from the 35 stock, and a slimmer faster tapered needle(Barons or DJ), yet drop the Main from a 182.5 Mikuni, down to a 172.5 Mikuni and improve their mileage, considerably. Often seeing gains from 5 to 10 mpg's, depending on their riding style. 95% of the time(a WAG), the SVS issues usually died with the rejetting.




The possible drive shaft failure is a real easy check. If that's good, then I think like Ctkog mentioned, I'd move on to verifying I didn't have a vacuum leak. I'd remove the intake manifold and surface the flange faces, and replace it using Hylomar or the Permatex Permashield(new orings, if the old ones look damaged). Just because it's a known issue. I'd double check the cap or plug on the AIS port, on the intake manifold.
The OP is still concerned he may be fighting a short somewhere in the ignition circuit also. I'd make sure anything involved, was isolated from contact with anything from frame to throttle cables. I'd make sure they weren't touching anything other then what they are supposed to contact.
 
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#1020052
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Re:Firing on one cylinder 1 Month ago  
I know that was an answer to the other post about SVS, but some great and very helpful info in there! I had heard a lot about SVS but haven't ever had any signs of it at all. On top of that I run a couple ounces of MMO in every tank of gas and do (originally Techron and later Seafoam) shock treatments every time I change my oil. I pretty regularly blow any carbon out too as my work sits next to the on ramp for the freeway I take home every night. Rarely when running it wide open up the on ramp until I hit the rev limiter do I ever have any black smoke. And I pretty much only run Shell gas in it - never any off brand gas. So I've been thinking that SVS would be a long shot in my bike so it's good to hear it's mainly a 1700 problem!!
 
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#1020062
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Re:Firing on one cylinder 1 Month ago  
Let us all know what you find paladin. The arching is definitely curious. Check that front coil wiring and all grounds. As Skwearpeg said, "....make sure anything involved, was isolated from contact with anything from frame to throttle cables. I'd make sure they weren't touching anything other then what they are supposed to contact."

best of luck!
 
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Last Edit: 2017/08/17 12:23 By Ctkog.
 


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#1020087
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Re:Firing on one cylinder 1 Month ago  
Ctkog wrote:
Let us all know what you find paladin. The arching is definitely curious. Check that front coil wiring and all grounds. As Skwearpeg said, "....make sure anything involved, was isolated from contact with anything from frame to throttle cables. I'd make sure they weren't touching anything other then what they are supposed to contact."

best of luck!



Will do and thanks again everyone for the recommendations. The new (to me) ECU came in today too so I'll probably swap that out this weekend as well.
 
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#1020215
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Re:Firing on one cylinder 1 Month ago  
Progress.....sort of. I've now put in new plugs, replaced the resistors in the plug boots with 6 ga solid copper, double wrapped the coils and first inch or so of the spark plug wires with rubberized electrical tape, and swapped out the ECU box with a known good one. Also verified nothing else interfering with spark plug wires and no bare/worn spots anywhere. Nothing helped. I moved on to checking the pickup coil, it's within specs per the service manual as are the ignition coils. So I removed the carb & manifold. The manifold does have an abundance of cracks on the outside, but none go through to the inside. While I had it off though, i noticed I could see the intake valves in both heads so I thought what the heck, I'll bump the starter and see what happens. Rear intake valve opens and closes normally. Front valve - not so much. It not only isn't opening and closing, it doesn't even seem like it's trying to move. So I think I found my problem. Just not sure what's next at this point........
 
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Last Edit: 2017/08/19 14:23 By Paladin.
 
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#1020218
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Re:Firing on one cylinder 1 Month ago  
Paladin wrote:
Progress.....sort of. I've now put in new plugs, replaced the resistors in the plug boots with 6 ga solid copper, double wrapped the coils and first inch or so of the spark plug wires with rubberized electrical tape, and swapped out the ECU box with a known good one. Also verified nothing else interfering with spark plug wires and no bare/worn spots anywhere. Nothing helped. I moved on to checking the pickup coil, it's within specs per the service manual as are the ignition coils. So I removed the carb & manifold. The manifold does have an abundance of cracks on the outside, but none go through to the inside. While I had it off though, i noticed I could see the intake valves in both heads so I thought what the heck, I'll bump the starter and see what happens. Rear intake valve opens and closes normally. Front valve - not so much. It not only isn't opening and closing, it doesn't even seem like it's trying to move. So I think I found my problem. Just not sure what's next at this point........

You never mentioned if you confirmed good oil pressure. Several things could cause your intake valve to not move correctly. If you have no oil pressure you probably had the oil drive shaft break on you which sags out the lifters. That is fairly common on pre-2003 models that have not had the upgraded gear installed. Later models had that drive gear shaft made thicker at the shear point and don't have that issue.

It could also be a bad lifter sticking etc. It could also be a true physical SVS on the intake side which is rare but not impossible.

Start at oil pressure. If that's good there are guys who take MMO, Seafoam or penetrating oil and squirt it directly on the valve stems high, on the guide if possible, (while you already have the intake off that will be easy) and then turn over the bike and see if the valves begin to move freely. If that does the trick it's SVS. A better way to apply the penetrating oil is from the top with the valve cover off, so you have gravity working with you.

If it's not broke oil shaft or SVS it may be lifters, pushrods or something else


good luck
 
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Last Edit: 2017/08/19 21:16 By Ctkog.
 


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#1020224
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Re:Firing on one cylinder 1 Month ago  
Sorry, forgot to list that. I started it up and loosened the banjo bolt on the front head. Barely loosened it and it forced quite a bit of oil out all around the bolt so I don't think I have an oil pressure problem. Also, my gas tank had about 2 - 2 1/2 gallons of gas in it when all this started and I put a full can of Seafoam in the gas. So what's been shooting at the valve through the carb has a pretty high concentration of Seafoam in it. About a week ago I blipped the throttle a whole bunch and hit the kill switch while I had the throttle wide open, hoping it would leave a pretty good saturation of Seafoam laced fuel on the valves. I thought maybe if it was stuck, the fuel sitting on it over the week might break it loose.
 
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Last Edit: 2017/08/19 17:49 By Paladin.
 
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#1020229
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Re:Firing on one cylinder 1 Month ago  
If the valves are barely moving or not at all as you look at them through the open head port, and you have oil pressure, then you might want to check the lifters and cam. By chance were the lifters replaced not long ago? Replacing just lifters can eat existing cams, so I hear. I was okay doing just lifters once but it's not recommended by most on the forum for the reason of potential for cam eating.

To confirm lifter or cam problem now you could pull your front valve cover and watch the pushrod rise while cranking the motor. If cam was eaten, or the lifter is bad, you'll have very little rise from the pushrod and a lot of free movement.
 
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#1020236
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Re:Firing on one cylinder 1 Month ago  
Engine is box stock other than having the tranny recall done so nothing has ever been done to the lifters.
 
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#1020621
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Re:Firing on one cylinder 3 Weeks, 5 Days ago  
Getting ready to pull the front valve cover and watch what's going on. I bought some Seafoam Spray to spray onto the valve directly in case everything else seems to be working, thinking if it was just stuck i might break it loose that way. I had several people keep telling me i needed to do a compression test (not sure why since I now know the intake valve isn't working) so I got my hands on a tester and the rear cylinder (that works) 110psi. front cylinder (not working) 60psi. Couldn't find a spec in the service manual but that's a huge difference.
 
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