Need Help After Carb Overhaul

[Tarkus]

I'm normally pretty good with troubleshooting.  This has me scratchin my head.  Just a little background first:

Over the past few months the engine seemed like it wasn’t getting good fire on all cylinders on the right cylinder bank (#s 1, 3, 5).  Gas mileage was poor (< 30 mpg) and lots of popping and sputtering on decel.  The bike is 12 years old.  Never had the carbs cleaned.  So, I figured the carbs were due for a good thorough cleaning and overhall.  So...that’s what I did.  Not a whole lot of fun either.  But, I digress.  Fast forward to present:

The carbs are re-installed.  But it seems the problem is still there, only worse.  Getting good fire on cylinders 2, 4, 6.  But, not 1, 3, 5.  I noticed after starting it up and letting it idle, that the exhaust coming out of the tail pipes on the left side was warm (normal), but not on the right side.  I then noticed the exhaust headers on 1 & 3 were not heating up.  I could actually touch them and they were only luke warm.  Then after a few more minutes of idling I noticed the exhaust header on #5 was starting to glow red hot.  Had to shut it down at that point.  

So, while 1 & 3 don’t seem to be getting any combustion, #5 is overheating.  I am getting a good spark at all the plugs.  The carbs have not been synchronized yet and I’m sure they need it.  But, I can’t see that being the problem. Maybe I’m wrong.

By the way, this is my first time overhauling the carbs on a Valk.  But I do have plenty of experience at it on a V65 Magna.  So, I’m not new to this. But, have never encountered this kind of problem.   I am totally frustrated and wide open to suggestions.  

Thanks in advance

Michael      

[lew l]

Hi Michael,
   Im new to the Valk also but sure am used to carbs.  Try to drain on the float bowls on cyls. 1&3 to see if ther getting any fuel ( stuck float). I'm not sure but can you (we) switch a carb in the rack to another position to see any change???
     Good luck,  Lew

[Valker]

Each coil controls two cylinders. One may be out. Pop on decel is usually a vacuum leak like a split hose. Make sure there's no staining around the intakes.

[MP]

Loose exhaust stud nut will cause popping too.

MP

[Tarkus]

Hi Michael,
   Im new to the Valk also but sure am used to carbs.  Try to drain on the float bowls on cyls. 1&3 to see if ther getting any fuel ( stuck float). I'm not sure but can you (we) switch a carb in the rack to another position to see any change???
     Good luck,  Lew

That's a good idea about seeing if the float bowls will drain.  I'll try that.  Maybe the middle carbs could be switched...I'm not sure. But even if you could, switching things around is probably not a good idea.  I've had it pounded into my head how important it is that everything is reassembled in its original location when working on multiple carbs, even the jets.


Valker, I checked each plug for spark and they're fine.  I think that rules out a bad coil.  All the vacuum lines, hoses, gaskets, O rings are new.  But, I'll go back and make sure they're connected properly.  

MP, the exhaust nuts are tight.

Thanks for the input so far.  If you think of anything else let me know.

[jrhorton]

did you try cleaning the secondary jets or did you replace them with new?  Having helped on 4 carb cleanings over the past few years, those that tried cleaning and re-using the jets ended up going back in to replace them.  Those of us (two) that just replaced them with new had no problems.

The point is, either the jets didn't get thoroughly cleaned or they were accidentally scored during cleaning and lead to the same problems in short order.

[chuck416]

I curious as to what resolution to this problem is/was.  On this same note, when do the carbs need overhauling?  What with ethanol fuel practically universally the only option, does this have an effect on how often the carbs need tuning up?  I know the "how often do they need it (overhauling)" probably isn't a fair question, and is highly dependent upon how much one rides, and typical length of ride, and particularly does one ride year-round, with no long periods of month(s) long storage during winters.  I guess what I'm asking is, just how much of a 'garage queen' is the Valkyrie susceptible of becoming?  I've never owned a Valkyrie, but am shopping.....There is a whole lot to like about this model of bike.   Low center of gravity, great acceleration, plenty of torque, smooth, comfortable ride.  Can I get some comments on typical maintenance one may expect in ownership, or maybe personal experiences some have had.  Much thanks---Chuck

[MP]

The VALK is NOT a garage queen, which means if you ride it much, you have problems.  The opposite is true.  The MORE you ride it the better.  Thee problem is NOT riding it.  The ethanol fuel gums up those small holes quickly if let evaporate.  If you are going to let the valk sit for more than a few weeks, be sure to put your favorite brand of fuel stabilizer in the tank, and be sure to run it enough to get it into all the carbs.  If you do that, you will have few, if not ZERO, carb problems.

MP

[chuck416]

Thanks MP!  I read that quite a few guys use a fuel additive commonly referred to as 'sea foam'?  Is that the trade name of the product?  If so, what seems to be the rule on fuel additives?  Use it ever other tank-fill, or maybe three times a year on a regularly ridden bike?  Is there another product that seems to work best?  Much thanks for the advise.  I hope to be an owner soon.  I used to ride back in my 20s.  Just turned 50 (a couple of years ago), and am looking forward to that "pride of ownership" that only a great motorcycle seems to elicit.   

[don07tncav]

Chuck Seafoam is the brand name of a fuel additive. Some Walmarts carry the stuff back in automotives and you can get it at many auto parts stores. I use about half a can in a full tank once or twice a year.

[MP]

Thanks MP!  I read that quite a few guys use a fuel additive commonly referred to as 'sea foam'?  Is that the trade name of the product?  If so, what seems to be the rule on fuel additives?  Use it ever other tank-fill, or maybe three times a year on a regularly ridden bike?  Is there another product that seems to work best?  Much thanks for the advise.  I hope to be an owner soon.  I used to ride back in my 20s.  Just turned 50 (a couple of years ago), and am looking forward to that "pride of ownership" that only a great motorcycle seems to elicit.   

Yes, it is.  Techron also seems to be very good as a cleaner, not so sure about as stabilizer though.  If you use stabil, get the marine one, as it is formulated for ethanol fuels.  Ethanol in marine engines is very bad.

MP

[Mulepick]

Various thoughts...

My "down" season is coming up here in NV and I intend to desmog.  I've not yet messed with the carbs on the Valk but I sure have done it many times on the 1st gen GW I owned for >20yrs.  I like Seafoam or Techron as additives and if you're getting any gas through to the cylinders at all, rely on good gas/additives to clean the carbs v. pulling.  Over the years there was significant evidence to support using OEM rebuild kits over aftermarket for my '79; may hold true for the Valk.  As much as we resist it, combustion problems are usually electrical v. carb related.  Coil, plug, plug wire, timing, etc.  Nowadays, however, vacuum leaks rival electrical.  Lastly, did you adjust the float height yourself?  I think that's magical and should be done by an expert on a bench monitoring flow rate v. spacing; just my opinion.  If your floats are hung up, put the handle of a screwdriver against the bowl and give the other end a little whack before you decide to pull everything.

On the GW I ended up welding up a plenum and pipes and using a VW carb.  Worked OK too!

Let us know!

Bob

[ValkThree]

These motors are really fussy regarding carb sync. If the sync is off even a tiny bit you will have rough idle, poor low end power and backfire at most lower speeds. You will also experience low speed surging.
Carb sticks are a waste and don't work so I would stay away from those.

I found some standard auto vacuum gauges on ebay and built a set for under $100. I tweaked and adjusted until all six carbs were identical. I now can launch from a dead stop with no throttle and the bike purrs. Previously it ran similar to what you are describing - poorly.
As far as idle adjustment - from my experience the idle mix is pre restricted to conform with EPA so it doesn't really matter if you go 3 turns out or 10 it does not appear to ever get to a to rich position.

Here is a pix of the set - the clamps are used to calm down the needle pulsing - filling the gauges with vegetable oil works also but this crude method does the trick and is adjustable.

[The Anvil]

Carb sticks are not a waste. In fact a decent set is going to be much better than six cheap auto vacuum gauges and they do not require calibration. Cheap auto gauges can be notoriously inaccurate and inconsistent with moving parts (sticky needles) and if you whack one it can f**k it all up. I would hate to build that rig only to find that one or more of the gauges is reading way off and that's quite possible.

[jrhorton]

I agree that a quality set of gauges, like the Morgan Carbtune II is far superior to cheap homemade rig.

I don't agree that the carb sync is critical to the bike running properly.  There's a broad degree of error and contributors to the bike running properly and the carb sync is only the last piece after all other variables are properly set.  Popping, surging, etc. are the result of air leaks, gummed up jets, and running lean conditions such as improperly set needles and shims, not by the carb sync.