CV40 Carb rebuild – 2 quick questions

[GeoRocket]

Hi Everyone –

Thanks in advance for your advice.  Spring is finally here in Michigan!  Well almost...

It looks like I need to rebuild the CV40 carb on my bone-stock 1995 FLHT.  I think my slow (pilot) jet is clogged and my accelerator pump diaphragm has failed.  See details below.

Two quick questions:

1. Is there a preferred rebuild kit?  I see CV Performance "Premium" kit and the Drag Specialties kit with similar components.  I could also by OEM parts.  I see James has a kit for $$$$.  I want to do the job with the best parts available.

2. What parts should I replace?  I do not intend to remove the intake manifold.  It seems smart to replace the sealing ring between the carb and manifold.  Also the accelerator pump diaphragm, "O" rings (in the pump housing and for the float bowl) and of course the fuel valve.  Also the gasket between carb and backplate.  Is there anything else I should replace while I'm in there?

I was looking at these kits:
https://cv-performance.com/carburetor-rebuild-kit-harley-cv-carb
https://www.revzilla.com/motorcycle/drag-specialties-cv-carburetor-rebuild-kit-for-harley-1988-2006?sku_id=1010499

My vacuum piston is working but I will also check this.  I was not planning to touch the idle mixture screw unless necessary (the one under the plug).  Disassembly and inspection will determine the extent of R&R.  I expect it's pretty clean in there but you never know (see details below).

Thanks for any advice!

George


For those of you who like details.  Sorry for the long post.

1995 FLHT with 74k miles.  Stock – no modifications.  Stock CV40 carb and jetting.  I am the original owner.  It has always run very well.

At the end of my 4500 mile trip from MI to CO & NM last fall the following symptoms became more noticeable.

Symptoms:
1. Bike has been getting harder and harder to start over the last year or so.  When it does start it seems to run on 1 cylinder for 20-30 seconds.  My starting procedure has always been 2-3 quick twists of the throttle, then full choke with closed throttle, then crank until it fires.  It typically starts up in 1 or 2 attempts.
2. Bike is missing at small throttle openings and slow speeds.  For example, riding through town at 25 mph and 2300 rpm.  It never used to miss.
3. Bike does not miss at larger throttle openings or when under load.  It accelerates fine up to highway speeds.
4. After bike is warmed up fully the idle is lower than normal.  Idle has always been around 1000-1050 rpm.  It now idles around 750-800 rpm.  I have never touched the idle screw.
5. If I set 1/3 choke while riding, the missing goes away somewhat.
6. The off-idle throttle response is poor.  See below "accelerator pump is not working".

For winter storage I always drain the carb float bowl.  I have never noticed any contamination from the float bowl, and I do look.  I always fill the fuel tank and use fuel stabilizer.  It usually starts with 3 cranks every spring, but not today.

So I pulled the air cleaner and noticed that the accelerator pump is not pumping fuel into the venturi. 
I drained the float bowl and it contained around 15 ml of fuel, so the vacuum petcock seems to be working fine and providing fuel to the carb.  There were a few tiny black specs in the fuel removed from the float bowl – barely noticeable.

I did get it started (starting fluid) and took a 60 mile ride.  It had same the symptoms above.

Here is some additional info about the bike:
1. Air cleaner changed at 69k miles.  It's clean.
2. Compression check (hot) is 145 psi front, 144 psi rear.  Compression is OK.
3. Spark plugs replaced at 69k miles.  They look the same as they have always looked.  Lite tan to cream white.
It runs fairly lean as it's a stock Evo.  Plugs are OK.

I have some experience with motorcycle carbs.  I was thinking the problem might be:

1. Air intake leak.  However, the idle has decreased, not increased as I would expect for an intake leak.  I have not done the checks for intake leaks yet, because this does not seem the most likely suspect.
2. Clogged slow (pilot) jet.  Since the miss happens at low throttle openings (1/8) I suspect this.  It's also the smallest hole.
3. Clogged slow (pilot) air jet circuit, including the idle port or transfer ports that enter the venturi behind the throttle plate.  I have partially ruled this out after I sprayed carb cleaner into the slow air jet.  It seems that the idle port and transfer ports were clear as the carb cleaner sprayed through and into the venturi.  (I held the throttle plate open, bike not running of course.)
4. Failed accelerator pump diaphragm or clogged accelerator pump circuit or nozzle.  This seems a sure thing as the nozzle is not spraying fuel, or is spraying very little.

So it seems I have a few options to try to fix this:
1. Run a few tanks of fuel with Seafoam through the bike.  (I ran 1 tank with Seafoam through last fall but I still have the problem.)
2. Fill the float bowl with Seafoam and let it soak for a few days while the carb is on the bike.  Drain and try again.
3. Rebuild the carb.

[kd]

This is a great post.  Don't ever apologize for giving the type of information you have here when asking for help finding a solution to a problem.

Here's my thoughts based on your input.  There is a good chance you do need to go through the carb.  The age of the "wear" components like the diaphragm and seals dictate it's time to freshen them up. There is a high probability debris (varnish or silt) has contaminated the fine low speed jets also.  (Check the tank liner and look for rust while you're at it) Cleaning 2with an ultrasonic cleaner con be helpful but there are also some good solvents that work well.

Your description of the changes in the idle and low speed response, momentary running on 1 cylinder etc. would cause me to check the manifold seals before disassembly. The manifold seals get less sensitive under load when the throttle valve is open and manifold vacuum is lower.  Many of your symptoms can be caused by an intake leak and manifold leaks can change with growth as the temperature of the engine increases.  I would also ask why you wouldn't renew the manifold seals when you are at that point with a clear shot at changing them?  Imagine putting it back together and finding there is still a problem.

To me, the way you describe the slow transition to the poor running characteristics indicates any of the things (or a combination of) the points I have mentioned could be your growing issue.  If you take on all of the repairs at the same time you may never know which thing it was you fixed unless it shows up visually like an intake seal test or accelerator pump as you've indicated. I expect you'll get lots of help on this one because your information is so complete.  Keep us informed please. 

[fbn ent]

I agree that the carb probably is needing attention but I would check the intake for leaks before doing that work. I would also try a bit more Seafoam just because I'm lazy.

[SP33DY]

Three common things I have seen over the last 10 years or so is deteriorization of the fuel line and disintegration of the accelerator pump due to the ethanol content of modern gasoline, and bad float needles that stick or leak. The fuel line problem causes debris to enter the float bowl, or block the inlet needle off the seat. Auto parts stores carry fuel line that is compatible to the modern gas.

I have had no problems using CV Products carb parts in my shop.

[Fugawee]

Hi George...I will toss in My 2 cents here for what it may or may not be worth.

Besides doing what it appears to Me that You are planning on, such as dis-mantling the entire Carb...cleaning all the orifices, repairing, or replacing this and that...I would suggest that while all of that is out of Your way to just go ahead and replace the Intake Manifold Seals.  Might as well while You are pretty much there, and just get it over with.
I'm not sure whether or not Your Idle/Air Mixture Screw Plug is or is not removed.  If it is not, I would remove the Plug and inspect the Mix Screw Needle End.  You may be surprised at the amount of build-up on it.  Same thing with the Choke/Enrichener Valve.

Something else that may be overlooked is the Vacuum Piston.  If and when You should clean it...the Carb Cleaner overspray will probably get on the Rubber Diaphragm and will distort it's normal shape a little.  That will drive You nuts trying to line it up properly in the groove while attempting to install the Carb Cap.
A simple solution for it to go back to its normal shape is to do this...as taught to Me by an Old-Timer.
Cut the top off of an old Beer or Soda Can.  Place the Vacuum Piston in it so it is straight up resting on the White Plastic, and the Rubber is not touching anything.  Now, place it in Your Freezer for a couple of hours or so.  The Rubber will contract back to its normal shape, and go back in the groove, making installation of the Cap nice and easy.
I had a Vacuum Piston Rubber Diaphragm on a 94' FLHTC that had a very small tear in it.  How it happened beats Me.  You couldn't see it unless You held it up to a Light.  Take a good squint at that while its out.

I would also suggest that You write down all the Sizes of the Jets, and Needle that are in Your Carb for future reference...should You need to go up or down with any of them for performance reasons.
It wouldn't hurt to make sure that the Exhaust System is tight at the Heads also...seeing that You are kind of in the neighborhood.

I have also used many different Manufacturer's/Distributers Carb Re-build Kits over the years on HD's and Street Rods.  They all appeared to be pretty much the same to Me, with the exception of the price.

Good Luck!

[Hossamania]

All good advice. You will find the accelerator pump/diaphragm worn out, the spring rusty. Replace, and clean those ports well.
Your slide is probably due for replacement, I just bought OEM from my Indy for $50.
Remove your enrichener cable and clean that area and ports. Maybe even think about replacing it (cheap) or at least new o-rings.
Make sure your throttle opens the blade completely when re-assembled with the cables attached.
Good luck, they are simple and reliable carbs.

[GeoRocket]

Hi Gents – Thanks for your speedy responses.  This site is excellent!  I'm glad that folks still read the Evo section.

kd –

I agree it's time for carb rebuild.  I will check tank for liner problems also.  I also plan to confirm good flow from petcock before removing carb.

I'm hoping I don't need to soak the carb in a solvent tank, because I believe that would require I remove the idle air screw plug and the "O" ring that is beneath it.  There is a tiny "O" ring in there right?  The FSM and parts manual mention nothing about this plug/screw as it is not ever supposed to be touched (EPA).

I will check the manifold seals before I remove the carb.  Excellent idea.  I will likely use propane and a hose.  QUESTION: Doesn't a manifold air leak result in an idle speed increase?  Or only up to a certain point I guess?  General question.

I'll keep you informed.  In the spirit of HTT I hope this discussion will help others as well.

BTW - I hope to be in your neck of the woods this summer, either near International Falls or Thunder Bay/Sleeping Giant, or perhaps Marathon/Pic River/Pukaskwa N.P.  Still planning.  I take many vacations in Canada.

fbn ent -

Good advice – I'll try another squirt of Seafoam before checking for manifold leaks.  I'm lazy too.  Well not lazy, but I try not to perform unnecessary work because it's just another opportunity for me to screw something up.  Ha!

SP33DY -

Excellent suggestion regarding the fuel line – thank you.  That would explain the tiny black specks.  I will replace it.  Easy.
 
I wonder if the line joining the tanks at the front needs replacing also?  I guess the diaphragm in the vacuum petcock might also disintegrate, although mine has been upgraded.  I am channeling FSG when I mention Ser. Bul. M-1063A and the Recall Code 088 kit from 1 Nov 1996. 

Fugawee –

I will test the intake manifold to head seals.  My idle air screw plug is likely still there as the carb has never been removed.  Isn't there an "O" ring under there?  If I dip the carb I would need to take this apart and replace the "O" ring – right?

I will check the vacuum piston as you suggest.  Thanks for the tip for re-install (freezer).  Good advice.
I will also record my jet sizes.  I expect a 0.042" slow (pilot) jet and a 0.175" main jet according to the FSM.
I will also check the exhaust header to head joint for leaks while I'm in the area.  Thanks.

Hossamania –

Good catch on the enricher.  I had planned to clean/inspect that area.  I have a new cable ready to go.  Is the STARTER VALVE something that typically wears?  I will check it and clean it for sure.  I think the common problem is that the valve becomes sticky and won't fully seat causing a rich condition.  I don't have those symptoms but I will clean and check it, and replace if necessary.

I'm pretty comfortable with carbs generally (I'm old) but there are always little tricks and things to check.
Appreciate you Guys and your experience.  And especially your willingness to help others out!

George

[Fugawee]

Hi George...
Just for My own curiosity...how many miles are on Your Bike?  And are You the Only Owner?

To answer Your Question about the Idle/Air Mixture Screw...Yes, there is a very small "O"-ring on it.
There is also a very small Brass Washer as well.  If You are to remove the Mixture Screw, the Brass Washer will be placed on it 1st, then the "O"-ring.  The "O"-ring will be sealing up against the Carb Orifice.

If You are to dunk the Carb in Parts Washer, You may not be getting that Orifice cleaned out, or cleaning the Mixture Screw, and affecting the small "O"-ring.
If You need to access the Idle/Air Screw...which I would recommend...just drill a small hole, not very deep...just enough to make a puncture, and twist in a Sheet Metal Screw just enough to bite and yank the screw with the plug on it with a pair of Pliers.  The Screw itself is approximately 1/4" into the Tower beyond the plug and is a small Slotted Brass Screw with a Small Needle on the end of it.  It's not as difficult as it may sound or appear.

The reason that I am suggesting to just go ahead and replace the Intake Manifold Seals is that You will already have the Carb out of there.  You will also have the Fuel Line and Choke/Enrichener out of the way as well.  The only other thing that will need to be removed out of Your way is the Horn, if it is still in that location.  If the Intake Seals are original...it may be time.
And Yes...the Seals will have an effect on Your Idle, as well as overall performance.

As far as the overall Carb Cleaning...I prefer to use a spray Carb or Throttle Body Cleaner vs. a Parts Cleaning Tank or a bucket of Gunk Parts Cleaner.  I remove ALL of the Carb Parts/Gaskets/O-rings/Jets, etc.  Then use an old Toothbrush, or a Toothbrush style Brass Wire Brush in the Float Bowl and wherever else needed.  Spray it with the Cleaner again, then blow it all out with air.
Labor Intensive?  You might say that...but, worth it in the long run in My opinion.

These are only suggestions...as I am not at all into telling anybody what to do.
It's Your Bike, and Your Carb.

I hope that this may help You out a little bit.
And You are Welcome for the Response.
By the Way...I'm No Kid either.  I'm in My so-called "Golden Years".
Good Luck, Have Fun, and Take Care.

[Fugawee]

One other item that is often overlooked is the Fuel Filter above the Petcock inside the Gas Tank, especially if it is the Original.
Something else You may want to consider looking at or replacing.

[Hossamania]

Good point Fugawee, those things can become a swollen mess when left to sit for a while.

[GeoRocket]

Hi Gents -
A quick update...
I checked the intake manifold for leaks using propane and carb cleaner spray as many have suggested.
It appears to be leaking, so I will replace the manifold to head seals.
QUESTION: Do I need to remove the gas tank to replace the intake manifold seals?
I understand that the manifold flange bolts are to be tightened slowly with the carb and backing plate attached, so that the manifold remains aligned and not forced when the backing plate and carb are finally installed.   (Seals lubed of course.)
It does NOT seem possible to tighten the manifold flange bolts with the tank, carb and backing plate in place, even if I fab up a special tool.  It's just too tight in there.
Your thoughts?
Also - I checked for exhaust leaks with a long lighter and all seems good.
Fugawee - Bike has 74K miles.  Good idea to check the petcock screen.  If I need to drain the tank I'll do it.
Thanks again!
George

[Hossamania]

You might be able to just loosen the tank and lift and block it. Easier with it completely off, of course. If you're draining the tank, you're halfway there. Still a mess pulling the tank, always a little fuel spill when pulling the crossover hose.
Take your time to get everything lined up, replace all the old rubber parts, even the crossover hose, vacuum lines, any rubber vacuum plugs.

[fbn ent]

Hi Gents -
A quick update...
I checked the intake manifold for leaks using propane and carb cleaner spray as many have suggested.
It appears to be leaking, so I will replace the manifold to head seals.
QUESTION: Do I need to remove the gas tank to replace the intake manifold seals?
I understand that the manifold flange bolts are to be tightened slowly with the carb and backing plate attached, so that the manifold remains aligned and not forced when the backing plate and carb are finally installed.   (Seals lubed of course.)
It does NOT seem possible to tighten the manifold flange bolts with the tank, carb and backing plate in place, even if I fab up a special tool.  It's just too tight in there.
Your thoughts?
Also - I checked for exhaust leaks with a long lighter and all seems good.
Fugawee - Bike has 74K miles.  Good idea to check the petcock screen.  If I need to drain the tank I'll do it.
Thanks again!
George

If you can run it up on a couple 2" plank pieces and drain the tank from the petcock than stand it up straight to remove it you shouldn't get much spillage. BTW, I hate gas spills....I have found that to do a good job it is better to remove the tank.

[Fugawee]

George...if You go to the General Section here on HTT, there are two separate threads started by Barefoot.

They both say...2000 FLHT will fire but not start.

The 2nd one down that shows a Lock on it has some very good info as to the Intake Manifold Seals.
It is approx. 1/2 way down the page.

It will show You what You may be up against, and the Tools that will make Your Life and the Job easier.
I have always had the Carb removed from the Intake Manifold when removing or installing the Manifold.

I can elaborate a little bit more later if needed.  I am pressed for time presently...as Higher Authorities here are DEMANDING that I go to Staples for Her to get a Printer/Scanner.
Just what I need...

[Fugawee]

https://harleytechtalk.com/htt/index.php/topic,119623.0.html

Forget the above post...
Here You Go...save You the Trip.

[98fxstc]

The manifold to head bolts can be difficult to get at and work on.
Look up Yost Performance intake manifold tool.
They are really useful, and I also use a 1" length of 1/4" hex key with a ring spanner to loosen to get started, and pinch tight to finish.

[Ohio HD]

I also use a short section of a 1/4" key that I cut off. I use a Snap-on 1/4" combination wrench that's strong enough to use the open end to get the screws cinched down. I can hold the short 1/4" key with a finger tip on the end, and work the wrench with the other. Fastest way I've found to get them on and tight. I then use the closed end to pull them tight.

[Fugawee]

As far as the replacement of the Intake Manifold Seals with Tank On, Tank Off, or Tank Propped or Pivoted up...I have done it each of those ways.  There is no doubt in My mind that it is by far easier, and safer with the Tank off.  Seeing that You will be giving almost the entire Fuel System a good going over I would remove the Tank.  If You are replacing the X-over Fuel Hose up front anyways...no big deal.  Just use 2 Hose Line Clamps on each side of the Hose near the Tank Nipples, cut it in the center, remove the Clamp(s) and drain each side one at a time.
After its drained, now remove, or at least loosen the Petcock.  Removing the Petcock if it's not loose while still on the Tank off of the Bike can sometimes prove to be difficult.  Difficult meaning Tank Damage.  With the Petcock off...now the Fuel Filter can be taken care of.  Next remove the Gas Cap, the Overflow Tube, and the Tank Console...no big deal.  Remove the Front and Rear Tank Mounting Bolts, Remove the Tank, and away it goes to a Safe Location.  And with the Tank off You can Inspect, Clean, Flush it...whatever You may want to do to it with it off.
I have a thing about Scratching, Scuffing, Dinging, or Denting a Tank, even with a Tank Protector on it.  The same thing goes for Fenders as well.  Even much more so if it's not My Bike.  Don't need it.

In the above link You will see some Photos provided by Smoserx1 showing the Tool for the Manifold Bolts, as well as replacing those Bolts with Standard Hex Heads.  It is much easier to deal with the Hex Heads versus the Allens.  And some other ideas as to how to deal with the Allens.
The two Allens that are on the Bottom of the Manifold Flanges really don't need to be taken completely out...they are Slotted, and the Flanges and Manifold will come right off provided that they are loose, and the two Top Bolts are removed completely.  I find it easier just to remove all of them.

I'm not saying that My Way is the right, or only way...but it has worked for Me for quite some time.
Whatever works for You...You're spinning the Wrenches, and it's Your Bike.

Just Pack Your Patience and Give it Hell!

[GeoRocket]

Hello Gents – Happy Easter! 

I guess I should have posted this in "General".  Thanks for the link to the Barefoot post Fugawee.

I removed my gas tank and carb.  I've had the tank off 2X before for lower rocker gaskets so no problem.

Carb was very clean inside.  Only smoking gun was the accelerator pump diaphragm – it was failed as Hoss predicted.  Also the small hole from the float bowl into the accelerator pump chamber below the diaphragm was clogged.  So that explains why the accel pump wasn't working.

Both the main and slow (idle) jets were perfectly clean, including the small emulsifier holes in both.  Fuel valve was also in very good condition.  I inspected the vacuum slide diaphragm and it was also in very good condition – no tears and very soft and flexible.  (It was working fine before disassembly.)

I had expected to find the slow (pilot) jet dirty and the cause of my low-speed miss and low idle symptoms, so there must be another cause.  I know my intake manifold seals were leaking before disassembly so this could be it.  And the manifold seals were surely disturbed during carb removal – they will be replaced.

So there are only 2 remaining causes I can think of for my low speed miss and my low idle speed symptoms:
1.   Intake manifold leak, creating a lean condition.
2.   Clogged "idle port" behind the throttle plate.  This is controlled by the idle air screw under the Welsh plug at the bottom of the carb spigot.  I still haven't decided whether to pull the plug to inspect/clean this.
   
Could a vacuum leak cause a decrease in idle speed?  I'm trying to understand cause/effect.  FSM states in TROUBLESHOOTING Fig. 4-12: POOR IDLING Check for: Inlet system air leak (faster idling).  It seems that any manifold seal leak would have more effect at small throttle plate openings where manifold vacuum is higher, so it seems that this leak could contribute to both my low speed miss and low idle symptoms. 
 
I have ordered a carb rebuild kit including seals.  Now I just need to remove the intake manifold.  The fasteners are pretty tight.  I have ordered the Yost wrench for installation as suggested by Fugawee (thank you Sir).  I will also fab a simple tool from ¼" hex so I can use my small ratchet and torque wrench on the bolts during installation.
 
What is the intake manifold bolt torque spec?    I cannot find it in the FSM.  It's not under SECTION 3 – ENGINE - INSTALLING ENGINE (p. 3-14) nor under SECTION 4 – FUEL SYSTEM - INSTALLATION (p. 4-19).  There is a general reference in SECTION 1 – PRODUCT (p. 1-10) FASTENER TORQUE VALUES – ENGLISH SAE 8 STEEL 150,000 PSI for ¼" Allen bolt = 14 lb-ft. 

Interesting: My carb had the #42 slow jet and #175 main just as I anticipated.  It seems that the jet numbers do not correspond to the jet orifice size measured in inches as I expected.  My #42 slow jet orifice was less than 0.020" (I didn't measure it exactly).   No matter, I was expecting 0.042".  It is clean/clear under magnification.

Waiting for parts.  Thanks again for all of the help!

George

[14Frisco]

What is the intake manifold bolt torque spec?    I cannot find it in the FSM.  It's not under SECTION 3 – ENGINE - INSTALLING ENGINE (p. 3-14) nor under SECTION 4 – FUEL SYSTEM - INSTALLATION (p. 4-19).  There is a general reference in SECTION 1 – PRODUCT (p. 1-10) FASTENER TORQUE VALUES – ENGLISH SAE 8 STEEL 150,000 PSI for ¼" Allen bolt = 14 lb-ft. 

In the 1993-1994 FLT Service Manual the spec (prob. same as for your 1995) is in two places.

• p. 4-1: Manifold to cylinder head bolts 6-10 ft-lbs
• p. 4-19 INSTALLATION, step 8: Tighten the socket head bolts (4) to 6-10 ft-lbs torque

[Fugawee]

I find it easier to use a Long Ball Head 1/4", 3/8 Drive Allen Socket on the Manifold Bolts.  At least when it comes time to remove them.  And use it again to Snug them up, then a 1/4" Allen Driver of whatever I have made up, with a Wrench or Socket.  I have had more problems removing them on somebody else's Bikes than on My own.  They seem to strip at the Head on occasion at the Allen Bolt Head during removal for some reason.  If that happens...out comes the Vise-Grips or some other type of removal Tool.
I usually put a dab of Anti-Seize on them during installation...for the next time.

Keep that Fuel Filter in mind, if You haven't already.  As well as the Air Mixture Ordeal.

It sounds like You've got a plan.

Your Welcome for the response.  I hope that a little of it may have helped You out.
Good Luck!

[Hossamania]

As long as you have the carb off, remove the welch plug from the idle mixture screw. You don't have to adjust the screw if you don't want to, but now at least you can if you find it might help later.

[JW113]

A big "I AGREE" on replacing the allen head manifold screws with hex head. Hundred times easier to get at and tighten, and frankly makes me wonder why H-D used allen heads in the first place.

If you have the tanks off, spring for one of these, you'll be patting yourself on the back next time you need to take the tanks off:

https://www.denniskirk.com/goodridge/5-16-in-in-line-fuel-quick-disconnect-coupling-lcd005v.p186347.prd/186347.sku?cid=17923638713

Just make sure you get the right one for the size of your crossover hose.

Very, very nice thing to have if (cross fingers) something goes south out on the road and you need to remove a tank or two.

One thing about replacing the intake manifold seals, just lightly 'snug' the manifold bolts, then put the carb and a/c backing plate on, and tighten it down. THEN, tighten the manifold bolts. This will make sure your manifold alignment is good and you don't stress the seals trying to get the carb back in place.

-JW

[xlfan]

"My #42 slow jet orifice was less than 0.020" (I didn't measure it exactly).   No matter, I was expecting 0.042"."

That is because the #42 reference is metric, as in 0.42 mm

[GeoRocket]

Hello All -

Just a quick wrap-up on this thread.
Short answer: bike runs good, and just as it should.
Thanks very much to all who offered advice as it was very helpful in doing the job properly.  I really appreciate it!

More details...

Intake manifold seals: I think the leaking intake seals were a major part of my problem.
(Recall that the accelerator pump diaphram was also rusted and leaking, and the fill hole to the pump chamber below the diaphram was also clogged.)
I would not consider removing the carb in future without replacing the manifold seals, as the removal of the carb from the manifold disturbed the manifold-to-head seals.
During installation of the manifold I carefully tightened the flanges - slowly and evenly.  I did this with the carb and backing plate installed to ensure good alignment of all seals.
It was pretty easy after I cut up a 1/4" allen key into 4 short pieces.  I used my 12 point box wrench to final torque the bolts, and a 1/4" socket, ratchet and extension on the front right bolt.
Thanks 14Frisco for the torque values.  I don't know how I missed them in my FSM - old age.

Idle mixture screw: I'm glad I took Hoss's advice and removed the idle mixture screw under the plug.  It was a bit dirty, but it also appeared to be incorrectly assembled from new.  After removing the screw and spring, I carefully picked out the "O" ring first, then out came the washer.  This is not the proper order as I understand it.  Recall that this carb has never been taken apart since new. So I installed it with the "O" ring at the top, followed by the washer, spring and screw.

Upon disassembly, the idle mixture screw was in there very tight, and appeared to have some locking compound on the threads.
So I carefully backed it out a turn, then in a turn until it had loosened up a bit.  Then I turned it in until seated and measured 1.5 turns out as the original setting.

Upon re-assembly I installed the screw at 1.75 turns out from seated.  The bike started right up after re-assembly, but had some slight backfiring through the carb when blipping the throttle.  So I adjusted the idle mixture screw to 1.5 turns out and it ran better.  After 2 test rides it seemed to run good as new, so I left it alone at 1.5 turns out.  It still had some minor backfire through the carb at cool temps (48degF) but it had done this since new.  (The Evo cough.)

Tank: I replaced all fuel lines and the filter screen in the tank which was available new at the dealer. 
I rinsed out the tank 2X also, but it was very clean with no flaking of the liner and just a few tiny specks of rust/dirt.

Overall this was an easy job. 

Now I need to do a valve clearance check on my new (to me) 2012 Suzuki VStrom DL650A.  I hope it doesn't need any adjustment, as I don't look forward to removing the 4 cams and messing with those shims.  Yikes!
Hey - it's a V-Twin, with ABS, fuel injection and nice bags, but it's a back up bike to the FLHT.  Or maybe I'll just ride it.

Thanks again Everyone,
George

[Fugawee]

Good Man!  Congratulations, I'm glad that it all worked out for the Best for You. 

[nibroc]

thanks for the update----glad it's running good

[Fugawee]

George, just to hopefully eliminate any confusion as to the Air Mix Screw.
It should be re-installed in this Order...

1=On the Air Mix Screw, place the Spring.
2=Now place the Small Brass Washer.
3=Now place on the Small "O"-Ring.
4=Re-install the Air Mix Screw in the Tower.  Adjust accordingly.

The "O"-Ring should be the 1st piece going in the Orifice to make a Seal.
Not the Brass Washer.
The "O"-Ring should be the Last Piece installed on the Screw, and the 1st going back into the Carb, followed by the rest.

I have about 6 CV Carbs sitting on a Shelf here...that I just checked, and that is the Order of all the pieces, on All of them.
Unless My eyes are playing tricks on Me...which wouldn't be the first time, I think that I read that Your Brass Washer was the last piece installed, and the 1st piece going back in.
If that is correct...it may explain why You have and had a "Cough".
The "O"-Ring is not sealing correctly.
And none of them had any type of Thread Sealant or anything else.  All Clean Threads.

The Service and Parts Manuals won't show it...because HD didn't want You to know about it.

[Ohio HD]

As Fugawee said, and is shown here in order.

[Fugawee]

Thanks Ohio...makes it a lot easier with a picture that is worth a thousand words.

[Ohio HD]

His probably looks like this. I first posted the screw from CV Performance.

[Fugawee]

Your probably correct.  Seeing that His still had the Plug in it.
All the ones that I had here to double-check the correct order were all Slotted Brass Screws.
Not Knurled., or He would have had access to it a long time ago.
I know a Few that had their Evo's worked on at an HD Dealer and their Carbs were re-jetted due to New Pipes and an Ignition System.
They got the Bike back with the Plug in it, after the Dealer tweaking the Carb and told them that they had to adjust the Air Mix.
Either way...it's the correct order .