Valk running on 3 cylinders

[dalai-lama]

I have been working on valks since 2000 but this one has me stumped.  I am working on a friends interstate trike and it is running on three cylinders, right side only. 

A little background.  Two other places besides me have worked on this over the last 3 years.  The first place tried to replace the clutch but never tightened the main clutch nut, nor staked it like it should be, and it backed off and the clutch plates came apart and plugged the oil pick and the debris and su

ch blew the motor.  The second place replaced the motor with a used one off ebay but completely screwed up the wiring.   The side cover would not go back on and there was wires everywhere.   I found 3 battery cables    2 were ground cables and neither of those went to the block where the should.  One was pinched behind the alternator cover against that bracket and one was connected behind the ignition switch.  The alternator cover loop broke because it is just plastic and they tried tightening that down to much.   The alternator was not charging and I saw there was nothing connected to the white exciter connector.   I actually had to pull the alternator because I could not find the harness.  It turned out that they either cut or broke the harness and it was completely missing and not plugged into the alternator.

I get that all straight and fire it up.  It has sat for over a year as I would get depressed while working on it    It was not running on all cylinders so I figured old fuel in the bowls (the tank was off since it came to my house) so I pulled the carbs and rebuilt them.   No joy.

I checked the compression and all are around 170 psi or so.  The left side is not firing.  I verified that using a laser thermometer, pulling the plug wires with no rpm change, etc.  I have another motor in my garage that I know was running, so started swapping parts.

I swapped the coils and wires even though a coil fires one cylnder on each side, but just in case there really as a fluke.  No change.  I swapped the EMC.   No change.  I check the valves on the left side and all are good. 

I verified spark on the left side by grounding the plugs and seeing the spark.  Also my meter with an inductive pickup reads the correct rpm when connected to #2, #4, or #6 so it also is seeing spark.  I also pulled and swapped plugs.  The left side plugs were wet so it appears there is fuel.  Pulling a plug wire on the right side has an immediate drop in rpm.  Doing the same on the left side has no effect.

A buddy suggested that maybe the exhaust was plugged with a mouse nest so i drop the exhaust this moring.  No change.

Initially when I checked compression on the left side, they were low.   My friend suggested maybe the rings were stucl.  I did a wet compression test and the compression came up.  #2 was initially about 60 psi so at the time I was thinking bent valves.  But the next week when I checked the compression again, they all were at 170 dry and about 220 when I did a wet test.  So whatever made the left side low to begin with changed .

One other thing.  I have the fuel tank off and have an aux fuel supply hitched up.  I also pulled the airbox, rather I did not re-install the airbox after pulling the carbs a second time just to recheck my work (they were fine).  I tried spraying starting fluid in the intake's to see what it would do.   On the right side the starting fluid makes it too rich and there is a pronounced rpm drop while the cylinders clear their throat.   On the left side, it is different.  There is a slight rpm increase and some popping and a backfire.  Totally different behavior  between the working right side and the non-working left side.

I am going to swap out the pulse generator next.   I am running out of things to check and swap however and am looking for any ideas.   I may pull the head and check it.   I did check the cylinders the best I could with a bore scope and the pistons look fine with no damage that I can see.  The valves also look ok but I cannot verify their seating but the compression test says that they are.

It almost seems like the left side is completely out of time and firing on the exhaust stroke and not the compression stroke.   I mean I see good compression, wet plugs to indicate fuel, spark from multiple tests.   The damn thing should be working.

Any ideas as I am at a loss?

[dalai-lama]

One other thing.  I have never seen this run since the motor was replaced.  My friend Karen rode the bike from the shop to her home about 30 miles and that is the only time it has been run since the motor was replaced.  She was lucky to get home with the alternator not charging and the other issues they the shop left.   She finally broke down and asked me to take a look.

So I don't know if has ever been firing on the left side since the motor was replaced.

[pancho]

I believe you do not have an electrical problem at all. Changing the pulse generators will not help as you have correct timing on one side. (one coil for 1 & 2, waste spark etc.) I would the carbs in the dead bank have fuel in them first.   

[Ken aka Oil Burner]

I remember reading a thread on the forum about someone finding their bank angle sensor missing a screw, and hanging down at an angle. With the history of this bike, the center cover has likely been off and maybe the sensor wasn't installed correctly.

Also, I found a thread where John Scmidt found that during some carb service work, he inadvertently tugged some plug wires at their coil connections.  http://www.valkyrieforum.com/bbs/index.php/topic,111532.0.html Look at reply #6. Because of the pin style of contact there, maybe there is spark, but it's not strong enough under actual engine load. The left side plugs being wet sounds like either there isn't enough juice to the plugs or too much fuel flooding those cylinders.

Good luck. Problems like these are what makes you want to tear your hair out... and I don't have much left for that sort of thing.

[matt]

Dang thats a tough one!!  When I get home tonight I will read again what you wrote and see if I can help. It would be awesome to get Karen back on her trike. I think I read plugs were wet? Did you open carb drains and confirm fuel In carbs?  Compression was off that bad then did wet it sat for a week and Compression was up?

Matt
Derry nh

[da prez]

Sounds like a fuel issue. Not likely to be dead on one side.
A real problem child. Recheck for fuel in each carb. Odd that three on one side are unemployed.

           da prez
 

[Avanti]

Could the key for the cam gear be sheared off or not there.

[Hook#3287]

Sounds like a fuel issue. Not likely to be dead on one side.
A real problem child. Recheck for fuel in each carb. Odd that three on one side are unemployed.

           da prez
 

I agree with da prez, sounds like a fuel issue and I dont see where you addressed that. I might of missed it.

My old Honda Service Manager would always say "spark or gas, confirm one, it's the other".

[Jims99]

I agree with fuel issue. Maybe the T is clogged going to the left side. Open the drain plugs and see if your getting fuel to that bank. With everything you’ve done, I would think it’s something simple. Doesn’t soun electrical to me.

[dalai-lama]

There is fuel.  And just in case I broke down this morning and swapped the whole set of carbs with another set that I have that came off a working interstate.  Same symptoms. No fire on the left side and the right side is fine.  There is fuel in the bowls on the left side verified by cracking the drains on each.

I hate removing and installing the carbs!

So what are the chances that 6 separate carbs in two separate sets of carbs are having the same issue at the same time.  Pretty small I would say .  I had to swap the carbs just to verify to my self that this is not a carb issue as far as I can tell.

Matt the carbs that I just put on were from the interstate that I bought up in NH that I think we were both looking at at the same time a few years ago.  My boy torn it down to the frame to replace the kickstand cross member and has never finished it.  That is where I am getting parts to swap in.  

I am going to pull the head next.  I did not swap the pulse generators.

[matt]

I wondered if you ever got it running the interstate from nh.
On Karen's bike you have fuel , spark and compression only other thing I can think of would be timing.
Have you pulled front cover yet?  I believe I read spark plugs were wet with fuel?  And I would do  a leak down test

Matt

[pancho]

I'd check what Avanti and matt suggested first, make sure the left cam is timed correctly. There are positions it can be in to cause the symptoms.........   although many would give other noticeable clues.