Right Side Cylinders Are not firing at idle...please HELP!

[blbowers]

I tried starting my '99 Valkyrie recently, but it would only run with the choke on.  I have discovered ALL RIGHT SIDE CYLINDERS ARE NOT FIRING AT IDLE.  However, they are moving since cold air being is being forced out the exhaust.  I troubleshot the problem with the following results:

1.   Plug wires were tested and they are functional.
2.   Spark plugs were tested and they are functional.
3.   I can ride the motorcycle and, under hard acceleration, the right side cylinders WILL FIRE at around 3,000 RPM.
4.   Upon deceleration, the right side cylinders cease to fire and the bike wants to stall at any RPM lower than 2,000 to 3,000.

I backed out the bowl screw on each right side carb and fuel began pouring out of a drain line beneath the bike.  I also noticed a small amount of fuel seeping from the bowl screw - so I guess the carbs are getting fuel.

I ran a can of carb cleaner through the system with no significant benefit.  PLEASE help me diagnose this as I am about to surrender and take it to a stealership.  Thanks!

[roboto65]

If it has sat for a while then I would suspect the low speed jets are clogged and they are hard to clean it's a crap shoot you may end having to replace them.

[Ricky-D]

Sounds like a coil problem to me. If I remember correctly, someone said the coils fire by side. You might check the ground there. ???

Nope, coils fire in pairs.  1 & 2, 3 & 4, 5 & 6.   

[Patrick]

You don't seem to have an electrical problem, these bikes have 3 coils and fire as Ricky-D stated.. It appears the bike has sat for a period of time and the low jets are varnished.. Run several tanks of fuel with full cans of Sea-Foam added and see if that helps.. Run the bike at a speed where the engine begins to run good then back off on the engine speed and continue until it tries to run better. Keep slowing the engine speed until the engine is running good in high gear below 2K.. If this doesn't work then its time to get your hands dirty..

[Tundra]

I'm no expert, but it sounds like your jets are clogged. I know Seafoam is a favorite on this board, I've never had any luck with it. I just use it for maintenance and storage. When I have a jet problem I use Techron or Lucas products. Strong dose in a full tank and run it at low rpm and then bang, it clears itself!  I would try this method, no matter what brand you choose before you dig into the carbs. You may get lucky

[blbowers]

I tried a carb cleaner from Walmart...I guess this Seafoam stuff is much better?  Where can I grab a can?  Also, does the blasted airbox have to come off for the low speed jets to be accessed?  I thought I avoided all of this by buying a bike with a jet kit already installed as I'm not a carb-guy.  Bummer.

Also, I noticed that the bike fires all cylinders at EXACTLY 4,000 RPM.  The fact that it's only the right sides and they fire at 4,000 seems very conincidental if not significant of something.  I dunno...maybe not, but good grief this is strange.  Thanks for the responses.

[John U.]

Patrick has it right. My IS ran just that way, no idle w/o the choke, would run like a scalded dog above 3000 rpm. My problem turned out to be rust in the tank (and the slow jets), which no amount of Seafoam or Techron will fix. If your problem is gummed up slow jets then it may work, but give it time. Get the bike warmed up and get on and off the throttle as Patrick said. Then do it again the next day and the day after. You might try Techron, I think it's a bit more aggressive. Oh, and use a strong dose, like a full bottle in half a tank.
If worse comes to worse you might want to consider replacing the 35 slow jets with 38s. They are more resistant to gumming up due to ethanol.
If your problem proves to be rust (get an inspection mirror) get back to us for more focused advice.
I just saw your recent post, yes the tank and airbox need to come off. The carb bank can be bungeed up on each side to allow the fuel bowls and jets to be removed. It's a PIA but it's not rocket science. We're here to help.

[roboto65]

Well the 4000 makes sense because that is about the time it is all the way off the idle jets. I am new to Valks also but not new to Hondas. Magnas that is and they are also bad about slow speeds clogging and your symptoms match those to a T...

[98valk]

check and replace the intake manifold o-rings. use the viton ones from redeye http://redeye.ecrater.com/
I have never had a problem with clogged jets, and my bike sat for the most of 1 yr in a garage, only put 2k miles on it that yr.
did have similar problem that u have, its was the o-rings. U should also check the vacuum diaphragm of the stock petcock if that is what u are using. check my posts a few months ago about aftermarket diaphragms and the need to use a snubber in the vacuum line.
good luck

[Thunderbolt]

was mandated by the Governor of our fine state here in Florida.  I took the tank and airbox off and hooked an external tank with 1/2 Seafoam and 1/2 gasoline.  Even sprayed a small amount of spray carb cleaner in and finally let it sit for a weekend with that mixture in the lines.  Fired it up after that and the junk was gone and ran perfect again.  You might try something like this before you pull the carbs and the jets.  Once teh ethanol has cleaned the lines out and all the junk has moved on through, you will probably be o.k.

[f6john]

Just a thought, do you have a dyna 3000 ICM. Friend of mine lost power on a trip to Daytona a few years back. No exhaust heat on the right side. I knew he had the dyna and had heard they give problems sometimes. Changed the settings on the dyna and it was hitting on all six again. It didn't last long though and he had to have his stock ICM  overnighted. We switched it out and no more problems. As I recall the rpm's didn't matter in his case.

[Madmike]

Is there any detonation when the right side is firing??  If the fuel system is obstructed and lean you may get detonation which can damage the pistons. 

[dreamaker]

About the Dyna 3000, I had one and sometimes it acted like it was running out of gas. I would shut the bike off and restart it and it would be OK. Got ride of the Dyna and installed a I/S module and problem was gone.
Also you can change the jets without pulling the carbs. I do it all the time. Taking my time it takes me about 3hrs for both sides.

Dan

[Ricky-D]

Yup, since the bike sits on a side stand, (the common denominator) all the carburetors on the right bank are experiencing the same fuel level inside the float bowl.

I don't think the right side is totally absent of firing, but as mentioned, you have to get out of the low speed circuit to experience running on all cylinders.

I hope you don't start monkeying around with any settings before getting the problem cleared up. Especially so if it ran good previously.

The low speed circuit on the right side carburetors is clogged.  It may take an extended period of time to get them all cleared up if they are totally clogged rather that a partial clogging where a cleaning agent can pass through (a little bit) and speed thing up.

I would suggest to run any kind of fuel system cleaner (the two mentioned are excellent) in a concentrated form (less that a full tank of gas) and continue until such time as the problem starts to clear.

It's not crap in the tank that is the problem since it's affecting all three carburetors on the right side.

Likewise it's not any kind of vacuum leak or valve train problem.

[Patrick]

If you can open the pilots a bit then try it,, sometimes that will break loose some of the varnish and help the Sea-Foam to work 'more better'..If the Sea-Foam doesn't seem to help then I'd clean just the right side low jets.. Pull the intakes and it seems a bit easier to get at the chambers.. Be mindful of the screw heads as Jap fasteners at times seem to be made from lead,, they can be soft as *&@# and its real easy to bugger them up.. Some folks have said they couldn't get the jets clean,but, they'll clean-up with a good soaking in some good[if there is such a thing now-a-days] carburetor cleaner.. Deep-Creep[made by Sea-foam] will also work..

[blbowers]

I'm all about science and deduction here and I'm in full agreement that the low speed jets are clogged (apparently fully clogged).  So, this weekend I'll pull the tank and airbox again.  Has anyone posted pics of what the low speed jets look like so I'll know once I see them?  Thanks for all of the help.  I'm certainly not feeling hopeless/helpless any longer.

[dreamaker]

This may help !! I change my jets without pulling the carbs out. For me its easier then taring the bike apart.



I got these at the local auto supply.



These are the tools I use. I made up this bit so I wouldn't bump the floats and it makes it easier to take the jets out when carbs are still on the bike. I used an antenna I got at RadioShack and cut it to size and soldered to the bit. Got one for the main jet also.

 Here some other shots of the carb and jets.



I suggest you change these Philip type (Japanese type bit) to socket head screws. Make sure you use proper bit on screws or you may strip the head.



I use these to cover the intake ports in the head. I got these at the local beer and wine supply, they are for mini kegs, they are called bungs. They work great for covering the ports.

I hope this helps.

Dan

[Ricky-D]

Dan, I just want to remark that those are great pic's and ought to be a huge help.

One thing I will add is the carburetor manufacturer purposely use soft screws for the float bowl. The thinking is that it's a lot cheaper to replace a screw than a carburetor body.   Socket head cap screws are normally a grade-8 and will strip out the threads in a jiffy.

[dreamaker]

I agree about the screws. I got socket heads from Factory Pro with my jet kit.  When I tighten mine I use finger feel, tighten to snug, not crank down on it.

Dan

[DavidT]

I love Forums!

This is exactly the problem I'm having...with additional kick to the head of I JUST had all 6 carbs out to replace all the o-rings.  I had no idea I had a non-firing at idle problem though or, as I had all the bowls apart, I would have cleaned all of them up.  Damnit!

Okay, on to the question.  Can I just leave my bike idling to try and clean out the slow jets or do I need to do the on-n-off throttle thing?

Thanks!
David