Cylinder 1 dead after rejetting

[Buza]

I have this weird issue with cylinder #1 which just don't want to get fixed. I soon running out of ideas..

Some backgroud:
Last summer I believe I had a hydrolock issue, it's described here:
http://www.valkyrieforum.com/bbs/index.php/topic,91651.msg907818.html#msg907818
I didn't try to run the engine at this point, fortunately.

I then drained the intake and took the carbs apart. I rebuilt carbs with redeye kit and also rejetted to #38 and #110, I didn't touch needle settings.
All the vacuum hoses and plugs are new, also new spark plugs and air filter. When everything was back together I did a test run and noticed that cylinder #1 is not working as it should, the pipe is considerably colder than others

At this point I measured spark plug wires and at least they are not severed, got some consistent resistance readings. I also took spark plug of and ran the engine while it was resting on cylinder block. Spark was normal as far as I can tell. I also switched spark plug wires between 1# and 2# and that did nothing, cylinder #1 still dead.

After all this I took carb bank off again and opened carb #1. I didn't find anything wrong with it, jets were clean and didn't notice any crap anywhere. I assembled everything and did test run just to see that problem is still there.

I've loosened the drains on 1# 3# and 5# and bowls had plenty of gas.
I haven't done pressure test but it's on to do list once I get the meter

We have near +0C weather here so when running I get good visual with exhaust gases. Cylinder #1 is not putting out anything. In fact I think that whole right side is not "smoking" as much as the left side but i'm not quite sure with this.

I have Cobra 6-to-6's without baffles. Could 110 main jets be too big and causing Cyl 1# running so rich that it won't ignite anymore? Besides this Cyl 1# issue everything seems to run fine.
Maybe I could try test running it without airfilter. If it's running too rich wouldn't that show it?

Do you have any ideas where to go from here?
Any help would be greatly appreciated.

[Itinifni]

What does the cyl. 1 spark plug look like?

Perform a compression test on all cylinders and post your results.

Matt

[pancho]

First thing I would do is a compression test on the cylinder,, if it is good, you have already verified that you have spark, so the problem will be the fuel flow,,, carburetor.   Hope you get her straightened out so you can do some riding in those cool temperatures Buza.

[Buza]

I did some further test runs and based on exhaust pipe temps and amount of exhaust gases coming from right side I'm starting to suspect that there could be something blocking fuel flow around carb #5.
Cyl #5 seems to run ok
Cyl #3 is running colder but it's not dead
Cyl #1 is cold and almost without life

Since that's the order fuel flows I could be onto something here. Need to go through all right side carbs and fuel lines.
I'll post the results in few weeks time when I have chance to work with this again.

[sandy]

Could the vacuum operation of the petcock be partially failing? It sounds like not enough fuel is flowing fast enough to supply all the carbs equally.

[indybobm]

Was this a USA bike? The reason I ask is that some non-US bikes had smaller main jets and a foam piece blocking off the air inlet of the air box lid. Did you sync the carbs after getting it back together>

[Buza]

I also rebuilt the petcock and even drilled open the leaking rivets and replaced with small bolts and nuts.
So I don't think it's petcock failing. Also the left side is running very well.

The bike was imported from US some years ago. Previous owners there were Volusia PD and Patrick Airforce Base.
Jets I replaced were stock #35 and #100, I checked the numbers.

[Firefighter]

Like others have said do a compression test first.

You said you didn't touch needle settings,, you have had them out and cleaned, yes?

If compression is good and spark is good that leaves fuel.  Let us know!

[Buza]

Like others have said do a compression test first.

You said you didn't touch needle settings,, you have had them out and cleaned, yes?

If compression is good and spark is good that leaves fuel.  Let us know!

Yes, I will do that.
Redeye rebuild kit had new seal for needle also so yes, I had them out and cleaned.

[Ricky-D]

Please do not think this is criticism but, I feel your problem could mostly be your technique, and testing methods and conclusions. First off, it was a mistake to increase the jet sizes and your exhaust,, (both) can be contributors to some of your problem.
If you are getting any kind of heat, however little, there is no problem with that particular cylinder, except for carburetion.
Without performing an accurate synchronization of the carburetors there is no way you should expect to get the results you desire, except for luck.
Whenever cleaning the carburetors, it is imperative to also be sure the low speed apertures gallery is clear and not clogged. There are four apertures in the carburetor and if any is clogged, or the gallery is clogged you can expect problems with the idle and just off idle (running).

***

[Buza]

Of course I'll take that as a criticism and all criticism is good  There's no real science without criticism and I think that dealing with Valkyrie carbs is kinda science 

I have to add one correction here. I didn't touch the exhaust, Cobra 6-to-6's were there already. I bought this bike last spring and during summer drove about 10k miles. I'm pretty sure it's running lean and that's why I rejetted it. Although I don't have any measurements to back this up. Another reason I pulled carbs apart was the bikes age and possible hydrolock issues which proved to be true.

Here's a clip from last spring when bike was on dyno.
https://www.youtube.com/watch?v=9tDQ9xizrag
There's quite a lot popping and backfiring when closing lower rpm's.

Yes, I know that carbs should be sync'd before any conclusive results, but at the moment I don't have any means to do that myself or get the bike to shop. But I would think that even without touching any carb-to-carb adjustments and by checking that those round "flaps" (or whatever those are called) open visually simultaneously, I would get it to run even adequately.
All I need at this point is to get it running so that I can safely ride about 100 miles/kilometers and get it synchronized and checked by pro's.

This is all very fun and interesting at this point since there's still about 4 months until next season. But if this bug takes more than 4 months to sort out it's not either fun or interesting anymore

[chnulleri]

Hi, I had perhaps a similar problem with my bike. Also cylinder one didn't wnt to work on low rpms - at high rpms the bike worked on all cylinders. I also checked the sparkplugs, the hoses and the ignition timing (even though I couldn't think of why this should cause a problem). At last I opened the cap of carburetor #1 and found a broken spring!! That was why my valk didn't run on all cylinders, because carb #1 opened to fast with the two halfs of the spring. At high rpms the open carb worked "fine"! I never saw this problem before at no bike and no car! 
Greetz from switzerland

@indibobm: yes european bikes have a main jet of 78 - the other ones are the same. And the foam in the inlet is really necessary! I don't know why, but I was looking for the troublemaker for a long long time after I took out this little piece of foam (the valk didn't want to ride over 3500 rpms). I was searching for the fault in the carbs which I had also rejetted with US cobra jetkit. That was before I knew that the jets were MUCH bigger in US-versions. I still can't imagine where this big difference comes from and why this little piece of foam spoiled the whole power??

[Blackduck]

chnulleri,
Quite simple really, the Valk intake is very small and the bit of foam adds restriction.
Take it out and you have to go to 100/102 mains the same as the bikes without he pad.
This small intake is part of the reason Valks like fuel when the revs go up, it acts as a choke and draws more fuel in.
Good design for noise control but bad for performance and fuel economy.
Cheers Steve

[Buza]

Umm, which piece of foam are you talking about?

[indybobm]

For a Lot of non-US bikes there is a rectangular piece of foam glued to the top of the air inlet on the lid for the airbox. Since you stated that the bike was imported from the US and has #100 main jets, you would not have the foam.

edited-keyboard gremlins at work!

[Robert]

Wow all this advice and he still hasent done a compression test or better yet a leak down test

[Buza]

Wow all this advice and he still hasent done a compression test or better yet a leak down test

Well, you can't measure pressure if you don't have a meter, can you? I got one just last week and it's on my to do list. Secondly the bike is about 200 kilometers away so I can work on it only now and then.

[Buza]

Here's an update.
I took problematic carbs (1, 3 and 5) apart once more and cleaned them and now it's running on all 6 cylinders. However cylinder 1 popping is still there. Also cylinder 2 has pressure way greater than other cylinders and spark plug on 2 had lots of soot, I mean a lot. I'm starting to think that ignition coil for 1 and 2 might have some issues and/or the spark plug wires.

I did pressure test twice and here's the results (PSI):

1) 153 / 155,5
2) 181 / 191
3) 152 / 154,5
4) 157 / 156,5
5) 152 / 155,5
6) 152 / 157,5

[longrider]

I am just taking a guess here.    Cyl 2 has been running rich for some time and has a lot of carbon build up on the top of the piston.  Would be nice to have a camera to look in the spark plug hole   However if it were me I'd bring #2 to TDC and fill it with a good quality carb cleaner or ATF and let it soak overnight.  Use a mighty vac in the morning to remove as much as you can   Then replace the plug with w known good one and fire it up   Should remove some of the carbon.  The pilot opened way too far on this carb previously could have been the problem  just my opinion

[Hook#3287]

I am just taking a guess here.    Cyl 2 has been running rich for some time and has a lot of carbon build up on the top of the piston.  Would be nice to have a camera to look in the spark plug hole   However if it were me I'd bring #2 to TDC and fill it with a good quality carb cleaner or ATF and let it soak overnight.  Use a mighty vac in the morning to remove as much as you can   Then replace the plug with w known good one and fire it up   Should remove some of the carbon.  The pilot opened way too far on this carb previously could have been the problem  just my opinion

I was trying to figure out why the overpressure happened and I thought something was reducing the volume or size of the cylinder, but couldn't think of what.

Your explanation sounds feasible.

[Firefighter]

Number 2 being rich is what causes the increase in compression. Gas or oil will seal the rings to cylinder wall better than normal and cause increased compression numbers. Why number two is rich is my question.

Back in the old days if we had bad compression on car engines we would squirt some oil in the cylinder and check the compression again. If the compression came up the problem was the rings and if the compression stayed the same there was a valve problem. Oil would cause the ring to seal better but couldn't help a burned valve.

[Buza]

I'm thinking if failing ignition coil for cylinder 1 and 2 could cause all this, incomplete/bad timed burn in cylinder 2 which in turn leaves a lot of soot and ultimately higher pressure, and constant popping on cylinder 1. What do you think? It would nicely explain everything.

There shouldn't be any issues anymore with engine getting fuel and air.

I read that by flooding the sooted cylinder with kerosene and leaving it dissolve for 12 hours would clean it. There's just the thing how to determine when cylinder is at correct "work phase". Maybe I could find it with pressure meter and by slowly rotating engine.

[Bone]

Can you switch coils and see if the problem moves with the suspected bad coil ?

[Buza]

At one point I did switched #1 and #2 wires, there still was popping in #1.
I haven't tried switching ignition coils if that's what you mean. Like taking coil for #3 and #4 attaching it to #1 and #2.

I think I'll just buy used coil and test with that.

[Bone]

Yes that's what I meant if you have access to a used coil having a spare won't hurt.

[Hook#3287]

Number 2 being rich is what causes the increase in compression. Gas or oil will seal the rings to cylinder wall better than normal and cause increased compression numbers. Why number two is rich is my question.

Back in the old days if we had bad compression on car engines we would squirt some oil in the cylinder and check the compression again. If the compression came up the problem was the rings and if the compression stayed the same there was a valve problem. Oil would cause the ring to seal better but couldn't help a burned valve.

ahh, cool info, thanks.

Why number two is rich is my question.

What could cause that?  The carbs need to be synced, so that could do it.  #2 opening earlier or more than the others. 

Could a vacuum leak cause #2 to run rich?  I would think it would be the other way around?

I don't think the coil is the problem, but just swapping the wires at both ends should tell you that.  It's been said there were 50K Valkyries made, so that's 150K coils out there and I can't remember hearing of any that have failed.  Maybe some have, but it's not common at all.    If it was the coil, wouldn't you have the same problems in both #1 & #2?  Besides, Buza says he swapped #1 & #2 plug wires and no change.

I think he should rule out the coils and move back to the carbs.

All you need to sync the carbs is two vacuum gauges and some rubber hose.  Investing in those would be less than paying someone to do it.

[Buza]

I bought used coil & wires from Florida for 25$ and will test that once they arrive. Not too expensive even if it turns out problem was elsewhere

And yes, I need to sync the carbs. The setup in below video looks good and safe so next I'll be doing some tinkering with bottles and hoses
https://www.youtube.com/watch?v=GaTRyHxvneY

[gordonv]

And yes, I need to sync the carbs.

Be the first in Finland to buy BonS digital sync, and be the Best Friend to all your other countries Valkyrie riders.

http://thedigisync.com/

I bought mine from his 1st run, over a year before I had even sold my GW and bought a Valkyrie again. Still haven't used it yet, been just enjoying riding too much, but hope to do it during this years annual spring maintenance day with my GW buddies.

[Robert]

If the spark plugs have been fouled it will pop, cleaning most times will not do it. It will also pop with a incorrect fuel mix.

[Pappy!]

Okay, as I understand it you have had the carbs apart and have "cleaned" them.
1. Did you verify that the complete idle or slow jet circuit was functional? If so, how?
2. You can verify spark to that cylinder very easily simply by partially removing the spark plug wire at the spark plug and at idle and listen for the pop of the spark.
3. You definitely need to sync the carbs. In the RedEye kit he provided you with a .004 brass feeler gauge. Did you use it to set the initial throttle blade opening with? This is important.
4. Leaving the carbs in place you can pull the intake manifold for #1 cylinder. Once pulled you can visually check the small calibrated idle fuel holes in the bottom of the carburetor bore. The first one should be only partially (approximately) covered by the bottom of the throttle blade. If the blade is covering this hole the engine will not idle on that cylinder. Open the blade manually and you can see these holes. Clean carefully with a piece of tag wire or a piece of copper wire stripped from an old piece of covered electrical wire. Pull your pilot adjustment screw and force some pressurized carb cleaner through the passage left by the adjustment screw/spring/washer/o-ring. You should see the cleaner freely flowing through the holes you just cleaned out. If you have a mirror check the pilot screw hole to make sure you didn't leave an extra O-ring in the pilot hole.
5. Okay, this is why the sync process is important. How the calibrated idle holes work. What is on the air filter side of the throttle blades, at idle,  is very close to atmospheric pressure. What is on the cylinder head side of the throttle blade is under cylinder vacuum. As the throttle blade opens it uncovers each of these calibrated holes and they pass from atmospheric to vacuum. As these holes "see" vacuum they start pulling the fuel/air emulsion from the idle circuit and start feeding it to the cylinder. That first hole is super important as far as being clean and is often overlooked.
6. Take a good look at where that throttle blade is. This is going to tie in with comment #5. Now that you have verified that the idle circuit is clean and clear, you have re-installed the pilot adjustment needle assembly and set it and before you re-install the intake runner, it is time to set the initial position of the throttle blade. Look closely. If the blade is almost completely covering the first calibrated hole then open that throttle adjustment slightly to just uncover most of the hole. It should now feed fuel.
7. Start the engine and verify #1 is running.
8. Sync the carbs!!!

You can go a bit further and remove the fuel bowl while the intake is off if you want. Fairly easy to do. You can then remove the slow jet and shoot the carb cleaner up through that passage as well and verify the idle circuit. Anytime you shoot carb cleaner up through this circuit always crack the throttle blades and let the cleaner back out that will accumulate from shooting out the front of the carb via the idle air bleed.  

[oldsmokey]

With the issue of more compression on #2, you would think that the plug may have chunks of carbon on it rather than soot.  Is it possible there may be a valve adjustment issue? A little loose, delaying its opening, closing a little sooner and not opening to full lift?

[Buza]

Valk is now running smoothly and with all cylinders. The problem of course was carb(s) out of sync.
I also changed the main jets from 110 to 105. Pilot jet is and will stay at 38. I guess cyl 2# soot issue will be solved once weather allows riding and I can give it some WOT.

At some point I'm planning to do dyno and fuel mixture check also.

Other upgrades during winter were re-chroming the cobra light bars and blinker grills, installing banshee horn and airbrushed Valkyrie themes on side covers.

Now I only need some spring/summer weather