# 1 Cylinder

[DK]

Based on fuel consumption, smell, sooty exhaust coating ( will blow black specks on garage floor when engine is raced ), and finally a sooty spark plug from the # 1 cylinder, the right bank is running very rich. As original, there is not a vacuum line connection to #1.

The right bank plugs are picked below. #1 is on the right. The plugs are NKG Iridiums that I installed about 4000 miles ago.



It is '2000 with 20,000 miles of which I have rode 12,000 during the past year. It has never burned any oil whatsoever, does not puff blue smoke on deceleration and the tailpipe soot is not  slick/ greased as from oil from oil.

It now hits reserve at +/- 95 miles. Big BF checked it over during InZane & adjusted the pilot screws and verified the recent DigiSync I had recently done as being correct. Before his adjustments, it was hitting reserve at+/- 75 miles.

It is a trike which will somewhat adversely affect mileage, but not this much.  Also, it has .38 low jets installed by the PO.

In the course of double checking things yesterday, I removed the #1 main jet & diaphram. The diaphram was out about 10 minutes before I began to reinstall it and I discovered that the "seal" around the outer circumference was distorted and pinched, indicating that it had not been properly installed. I massaged and gently reshaped it and put a few dabs of silicone paste in the groove to hold it in place while installing the cover.

Could the diaphram have been the cause?

What about vacuum problems even though # 1 is capped off. (With a new cap)

What else could be specific to # 1? Float valve?

Any help would be appreciated.

Dan

[Michvalk]

Obviously, too much fuel. Problem is most likely in that carb, maybe a stuck float. You need to get that fixed, as you could end up with a hydrolock. I would be very careful about starting it until you find the problem. You moght need to pull the carbs, and do a complete cleaning

[97BLKVALK]

Dan,

What a pleasure it was to meet you at Inzane Spearfish.  I wish we would've had more time to talk and so glad Rick was OK after the accident with deer.

I wanted to offer a suggestion that was sent to me awhile back. 

Check the "Starting Enrichment (SE) Valve on that carb.  I have heard that could be gummed up and is not allowed to travel all the way in therefore enriching that cylinder.  Spray enrichment valve with carb clean and then a little WD40 for light lube.

My 2 cents.

Michael

[DK]

Michael,

I was checking the enrichment valves when I discovered the # 1 diaphram problem.

I followed Rick back to Tulsa just to be sure his bike didn't develop a problem. We had an uneventful & enjoyable trip.

Enjoyed visiting with you at InZane & look forward to seeing you next year.

Dan

[westnek]

Dan,

What a pleasure it was to meet you at Inzane Spearfish.  I wish we would've had more time to talk and so glad Rick was OK after the accident with deer.

I wanted to offer a suggestion that was sent to me awhile back. 

Check the "Starting Enrichment (SE) Valve on that carb.  I have heard that could be gummed up and is not allowed to travel all the way in therefore enriching that cylinder.  Spray enrichment valve with carb clean and then a little WD40 for light lube. hi all = a dummy here but is the SE valve  same as mixture screw - if not  - can it be reached easy or is it one of those issues I have to take the bike apart to see it ... thanks west 

My 2 cents.

Michael

[Ricky-D]

I don't understand. What is the question.

Those plugs look Ok to me and that is not the correct view of a plug

if you are looking at the plugs for running condition.

Here:  http://www.dragstuff.com/techarticles/how-to-read-plugs.html

***

[DK]

Based on fuel consumption, smell, sooty exhaust coating ( will blow black specks on garage floor when engine is raced ), and finally a sooty spark plug from the # 1 cylinder, the right bank is running very rich. As original, there is not a vacuum line connection to #1.

The right bank plugs are picked below. #1 is on the right. The plugs are NKG Iridiums that I installed about 4000 miles ago.



It is '2000 with 20,000 miles of which I have rode 12,000 during the past year. It has never burned any oil whatsoever, does not puff blue smoke on deceleration and the tailpipe soot is not  slick/ greased as from oil from oil.

It now hits reserve at +/- 95 miles. Big BF checked it over during InZane & adjusted the pilot screws and verified the recent DigiSync I had recently done as being correct. Before his adjustments, it was hitting reserve at+/- 75 miles.

It is a trike which will somewhat adversely affect mileage, but not this much.  Also, it has .38 low jets installed by the PO.

In the course of double checking things yesterday, I removed the #1 main jet & diaphram. The diaphram was out about 10 minutes before I began to reinstall it and I discovered that the "seal" around the outer circumference was distorted and pinched, indicating that it had not been properly installed. I massaged and gently reshaped it and put a few dabs of silicone paste in the groove to hold it in place while installing the cover.

Could the diaphram have been the cause?

What about vacuum problems even though # 1 is capped off. (With a new cap)

What else could be specific to # 1? Float valve?

Any help would be appreciated.

Dan

Ricky D:

As to "what is the question", absent your inferring that I'm asking why my Valk is burning too much gas, three specific questions were posed:

Could the diaphram have been the cause?

What about vacuum problems even though # 1 is capped off. (With a new cap)

What else could be specific to # 1? Float valve?



The three questions were prefaced by what I deemed to be relevant facts tending to rule out some likely possibilities and, conversely, to suggest other possibilities. Those facts include: sync and pilot screws recently set by a well-known, top-notch Valk tech ( Big B.F. ); the right exhaust blows gasoline soot; the #1 spark plug is sooted, while all others are normal; the #1 jet diaphram was discovered to have been improperly installed; the engine has burned no oil over 12,000 miles to my knowledge; the "soot" I complain of is not of oil origin ... you get the point.

I concluded my missive with the statement "any help would be appreciated" following my three questions regarding what I thought could have been some possibilities. I assumed that by asking for help, it would be understood that I was seeking other possibilities as to the cause of my problem and/or the accuracy/inaccuracy of the possibilities I posed.

I appreciate your referring me to the article on reading spark plugs. However, I'm not concerned with evaluating heat ranges for dragster engines. It's pretty simple reading when five look great and one (from the rich side) is sooted up enough even to be discernibe in my lousy photograph.

So, as to what is my question, the one I pick which I know least about would be: Could the mis-installed diaphram at #1 cause the problem, or do you think it is more likely a sticking float valve, and finally my biggie; what else is specific to # 1 that would cause it to run richer than the others given that it's vacuum port is plugged?
I hope this is sufficient detail as to what is my question (s).

Dan

[Ricky-D]

First off, I suggest to replace the spark plug. It may be faulty. If you have corrected the diaphragm problem and it was the cause, you should see the results on the new plug. A sticky float bowl needle or float can and will possible lead to loading the cylinder with gasoline, which you can easily notice when the engine is idling. Easy enough to check the performance with the float bowl removed. The #38 jets are unnecessary and contribute to your problems.

***

[DK]

Ricky D,

I completely agree with you about the .38 jets. They were installed by the P.O. & im going to change them out hopefully within the next couple of weeks.

When I put the plugs back in, I switched the #1 & # 5 plugs to see if the #1 plug was bad.

I haven't had a chance to ride it since discovering the diaphram problem other than just some short errands.

I failed to mention that it "bogs down" in high torque situations when given full throttle all at once, but if the throttle is smoothly and progressively opened, it accelerates normally with good power. I think the diaphram may have been responsible for this. We'll see soon.

Thanks for the advice,

Dan

[Rio Wil]

It might be just the angle of the photo, but, those gaps look way too wide......

[Firefighter]

Hopefully you figured it out, but if not I would check compression next if you have not already.

[longrider]

This is where I would go with this.     Are you sure the diaphragm is in good shape.  Is the float saturated.  A high fuel level caused by a saturated float will also cause loading of the cylinder.  So, if both are good then I would install a new float needle and adjust the level according to the specs.  Set all of the pilots to 2.25 when you change back to 35's.  The motor shouldn't bog.  Does it pull without bogging if you climb a hill at full throttle for say half a minute.  If setting the pilots does not cure the bogging then I would suspect a fuel delivery problem to the carbs.   Just my opinion

Warren

[DK]

Ran the Valk 300+ miles today. She's running with the big dogs listening to Bob Seger again.

The mis-aligned diaphragm definitely was the problem.

Im going to check the sync just to be sure the bad diaphragm didn't affect the previous sync & I'll check the plug after 800 or so miles.

Thanks, everyone, for the helpful suggestions.

Dan

[nogrey]

This is where I would go with this.     Are you sure the diaphragm is in good shape.  Is the float saturated.  A high fuel level caused by a saturated float will also cause loading of the cylinder.  So, if both are good then I would install a new float needle and adjust the level according to the specs.  Set all of the pilots to 2.25 when you change back to 35's.  The motor shouldn't bog.  Does it pull without bogging if you climb a hill at full throttle for say half a minute.  If setting the pilots does not cure the bogging then I would suspect a fuel delivery problem to the carbs.   Just my opinion

Warren

Glad to see the problem is solved. Question regarding pilots from the quote above: My  understanding is that pilots are only affecting the slow circuit and have only an impact at idle. Is this incorrect?

[longrider]

From what I have read from those that know on this site is the slows generally feed the fuel below 3000 rpm.  DK stated that if he moves the throttle from idle quickly to full it would bog.  That is why I suggested a problem with the slows.  One thing I wonder about though,  one would think the slows would be more associated with throttle opening not rpm.  Say if you were running 2000 rpm and wide open throttle the mains should be taking over.  Yes?

[BonS]

The low and high speed carburetor circuits aren't simple on/off modes. Rather, they transition between one another depending on the load of the engine. At cruising speeds the slow speed circuit is a major contributor of fuel flow while at higher speeds or wide open throttle it's not. I'd say it's 60% of the fuel flow at 40mph cruise, 40% at 60mph and almost nothing at 70+mph is attributable to the slow speed circuit. WOT is mostly high speed circuit.

[DK]

Bon,

I notice you are doing some research concerning DigiSync & defective diaphragms.

Although my diaphragm was not defective, but incorrectly installed, would you expect correcting it to require re-syncing?

Both I, and Big BF synced the carbs with the diaphragm incorrectly installed.

I'm going to re-check just to have an excuse to use this really neat tool I found on sale for $175.00.

Dan

[BonS]

Bon,

I notice you are doing some research concerning DigiSync & defective diaphragms.

Although my diaphragm was not defective, but incorrectly installed, would you expect correcting it to require re-syncing?

Both I, and Big BF synced the carbs with the diaphragm incorrectly installed.

I'm going to re-check just to have an excuse to use this really neat tool I found on sale for $175.00.

Dan

Since it's easy to recheck and you have such a nifty tool I'd do it to be sure.

I just purchased a couple of spare diaphragms and expect to get them this week. As you seem to know I'm going to be intentionally damaging them to see the effects of such damage, or leakage, determine how it can most easily be detected, and whether it affects synching at idle, high rpm's without load, or only with the engine under load. It may take a week or two to conduct these experiments in their entirety.

[DK]

I'll let you know whether or not mine requires any reset.

Dan

[Ricky-D]

A damaged diaphragm should not affect the idle vacuum since the slides are not doing anything at idle. Idle is 100% controlled by the butterfly valves and that is what is adjusted (the butterfly valves) when synchronizing.

***

[longrider]

The low and high speed carburetor circuits aren't simple on/off modes. Rather, they transition between one another depending on the load of the engine. At cruising speeds the slow speed circuit is a major contributor of fuel flow while at higher speeds or wide open throttle it's not. I'd say it's 60% of the fuel flow at 40mph cruise, 40% at 60mph and almost nothing at 70+mph is attributable to the slow speed circuit. WOT is mostly high speed circuit.

BonS

That is exactly what I thought.  It's the transition that is important to smooth operation.  I've opened the pilots on my new to me 2000 to 2.5 but plan on setting them back to 2.25 after I run a few tanks with some techron in as I'm running a bit lean.  The PO had new mains put in because the bike wouldn't run (sat for two years)  It does run smooth now though just worries me. Getting a consistent 190 miles on the main before reserve (IS tank) at 75 mph on the highway.

Warren

[BonS]

I've been doing some sync testing with a bad diaphragm and have some interesting results to share. I'll start a new thread to give it some additional visibility as it may help others diagnose carburetor ills.

[Ricky-D]

Turning the pilot screw from a setting of 2.5 turns to a setting of 2.25 turns is virtually insignificant in affect to carburetion

***

[longrider]

Ricky D

I agree.   Just trying to open things up and get a bit more fuel flow while running some techron through it.  Hard to believe I can get 15-20 miles more on a tank on this valk compared to the previous two.  And I was running HARD in some mountain roads, close to the red line a lot and still managed 190 miles on the tank. Plugs are a bit white as well showing a little bit lean

warren