Having fuel problems

Forum rules
Please do not start new topics here, but here: New Panhead and Flathead topics
Post Reply
Posts: 1006
Joined: Tue Mar 16, 2004 5:52 am
Location: Sultan, WASH
Been thanked: 2 times

Having fuel problems


Post by mbskeam » Wed Jan 21, 2009 4:05 pm

Author: Mbskeam

well if you kill it with the clutch it will stop real quick ;D and not keep on turning over....
one mine if I go in to a store, etc.... I turn off the gas, this helps big time on mine, yes its the carb, and the kick stand leans it way over so that don't help, I have seen it draw fuel down into it self when working on after ridding and it being up to temp.

Post by 03Roadking on Sept 22, 2005, 5:25pm

I pulled the carb and according to J&P there are no smaller jets I'm on the smallest Has anyone tried the adjustable jet for a Keihin I noticed they sell one in J&P and I was wondering if they really are any good, With all the trouble I had with the adjustable main on the Bendix I don't want to waste the money if they aren't very accurate. I have put about 75 miles on this set of plugs I am going to take a look at them tonight

Post by kevsett on Sept 30, 2005, 11:04pm


I've been reading your saga from the beginning and cheering you on quietly from the sidelines. At times I've been so angry at my 64 but things usually had a way of working out.
In the recent 3 years it went from a 1 kicker to kicking it til I almost passed out (yes, I'm stubborn when it comes to starting it). I checked and re-checked a whole lot of stuff, including the linkert/float/etc b/c "it couldn't be intake leaks".
Then it became obvious the O rings were not properly sealed and goopy silicone type sealer (I didn't put that gunk in there) was a part of the problem and then I learned that the Linkert's soft brass carb flange was curved/bowed and needing a little sanding to flatten.
All Winter I debated an S&S carb.....then the Spring.......then the Summer.......and now Fall; giving it little to no attention (mostly working, riding a 2000 FLSTC, and doing my dad/husband thing). But your situation is like a shot in the arm to get things rolling again (with the linkert). Thanks.
Now that your about there do me a favor and ride it like you stole it!!!


Post by 03Roadking on Oct 4, 2005, 4:13am

Hello Kevin
Glad you are taking the wrench up again ;D Don't know how old your kids are but my grand-kids are willing to help (where they can) for a ride or two on the "Butt Buster" ;D 62 in a 56 ridged chopper seat I am not totally out of the woods but I am really enjoying the bike more. I found two ways around my hot start 1 turn the gas off and when it starts to idle high shut the key off 2 last ditch is to pull the plugs kick it 4 or 5 times to air out the cylinders put the plugs back and one kick and I'm on my way I am not giving up on the carb I am going to get it so i don't have to do the above but here in Calif. I still have a few weeks of good weather and the rest of the year of OK weather so I don't want to go at it for a few more weeks. I wish you luck and Panhead needs a vote of thanks for the site for without it we wouldn't have all the help and knowledge from all over the world

Post by fourthgear on Oct 4, 2005, 1:48pm

Do you still have the Kiehn carb on there ? You said you shut the gas off and it gets to a high idle. Sounds like you have fuel infiltration from some where in the carb. and its mildly flooding the carb. and your combustion chambers. That would be why you are airing the plugs out to restart it . Does it shut down when you turn the ign. switch off or does it keep firing when shut off? Compression should stop it from turning over pretty quick, if its not firing off. A common problem is dieseling , its where there is carbon or other things in the combustion chamber which still glows when the ign. source is shut off and it continues to fire off , some what incomplete combustion and that can cause mild flooding or wet plugs .

Post by 03Roadking on Oct 4, 2005, 5:48pm

Yes I still have the Keihen on. It does not diesel. I turn the gas off and wait for the idle to go up after about thirty seconds then turn the key off. I have tried just kicking it and you can smell the gas coming out the pipes so I thought I would try burning the fuel that was left in the carb just to see if it would give me a better start and it did. Now that I'm here I do have a question there are two removable jets the large (Main jet) and the small one, is this the idle jet? It runs really good and I can hold it at any speed without bogging or flat spots so should I just try and find a smaller idle jet or do you have to replace both, I really don't want to mess with the main if I don't have to but the plugs look black after about 100 miles

Post by fourthgear on Oct 4, 2005, 9:02pm

I think its high and med. speed jets and I think you have a idle mixture adj. screw , I may be wrong about that . I keep thinking you had to pop a cap off to get at it though. A factory plug or some thing covered the adj. screw. In what condition is your throttle body and butter fly valve? The whole purpose of the butter fly valve it to regulate fuel/air mixture going into the combustion area, if there is a problem with it it could be letting fuel bypass it. I think the bottom part of the valve is where I would look at. Have you tried to run your Bendix since you straightened out your valve train.

Post by Sidecar on Oct 4, 2005, 9:08pm

Are you sure that the float is adjusted properly and not dumping fuel into the cylinders.
After you do the "run the carb dry" routine what happens if you turn the fuel back on and let the bike sit for 5 minutes without trying to kick it over ? Will it flood the cylinders again ?

Post by Mbskeam on Oct 5, 2005, 5:01am

do you have a stock fuel shut off?you know, the thru the tank style.
if you do that might be your problem as many of these still leak when closed, like mine.
so I have added a 2nd valve on mine. it is in line ,up close to the tank, this stops all the fuel from leaking past the carb into the engine,as winter is coming up this helps for long term sitting.

Post by 03Roadking on Oct 6, 2005, 5:20pm

This is important to me so I need to answer all your questions
I have been all over the carb I can not find any screw other then the air screw on the top of the carb. The throttle body looks good and when I rebuilt the carb I made sure there was a good fit on the throttle body to butterfly valve. I have not tried the Bendix Since I re-adjusted the valves
Hate to say it but I just installed the float valve without checking the float level I looked at all my books and could not find the measurement and the kit I had, had no paper work do you have the measurement??
I will try your idea tonight I will let the idle go up shut the key off wait five minutes turn the gas on and wait 5 to 10 minutes and then try it
No this is an old school chopper with fat bobs I replaced the petcock weeks ago at the beginning of this thread
If I get a picture of it I will post it. The bike that is not the petcock ;D

Post by fourthgear on Oct 6, 2005, 7:19pm

I would check the float first , sorry but my memory does not remember the float setting on a Keihn carb. and I don't have a tech manual anymore on them ( its back in Ohio ). For your motor to revving up when turning the fuel off , it shows its probably leaning out when the level gets low(float bowl ) I'm surprised your plugs aren't showing a rich mix.When you put the bike on its jiffy stand , the fuel is just running down hill as was said. There is on some Keihn carbs a plug that is popped off as I said , not sure if it was to put an adj. screw in or uncovered one , its been a long time since I worked on a Keihn carb , we just put an S&S on and did away with all the problems and draw backs that went with the Keihn, one of them was the inability to properly adj. them.

Post by Sidecar on Oct 7, 2005, 4:11pm


I don't have the measurement for the float. I normally did it by eye. My floats look about level when I do them. If it lets too much fuel in they will normally overflow. If there is not enough fuel in the bowl, it will run out on real hard accelerations, especially hills when hard on the throttle.
Take the cover off the float, push it up ( like it would normally shut the fuel off ) and turn your petcock on and see if fuel comes out. If fuel comes out you've got problems. If all is good, start to let it down till fuel starts to come out. Push it back up again to see if the fuel stops.
Adjust the float a little bit to shut the fuel off sooner when you push it back up.
Of course, no smoking while doing this !!!!!
Oh yeah, turn the fuel off while you make float adjustments

Post by 03Roadking on Oct 7, 2005, 5:40pm

I went for a ride last night when I stopped I shut the gas off and let it idle for about 30 seconds when the idle went up I turned the key off I waited as long as it took me to lock it up take my gloves off ETC then I turned the gas back on and went into the store I was in there about 20 minuets came out turned the key on and kicked it once and it fired right up. I went for about 5 miles pulled into a gas station and did it again same procedure and it fired right up So I think it's over carbureted? not leaking into the manifold?
I waited a while so it would cool down and pulled the plugs they are black sooty this is the second pair I put in so I am getting to much fuel, the inside of the pipes are sooty also I pulled the carb off and I have 1.75 main and .68 idle? while I had the carb off I checked the float and it looks to be set right.

Post by Gorillia Bob on Oct 8, 2005, 8:00am

Besides getting the plugs all sooty, too rich also washes off the oil on the cylinder walls, causing more premature wear

Something to consider. Try a CV they are very tunable & have great response & easy on gas..The early keheins needed improvement..

Post by DJ on Oct 8, 2005, 7:50pm

Yes, Gorillia Bob....... I have been considering going to a CV myself. Here is a very good tutorial for the upgrade. Some guy sells the necessary flange for the conversion on e-bay. There is a link to it in the article. http://www.harley-performance.com/cv-carburetor.html

Post by Billy on Oct 9, 2005, 6:50am

;D Yep only cv's for me, on any HD..
Once you try one. You will likely forget the name of the
"thing" ya had on there.....

Post by kell on Oct 9, 2005, 4:03pm

Are CV carbs any less prone to developing air leaks in the manifold fitting?
The problem in general is finding a way to support the weight of the carb.
I noticed the article says attach the carb to the heads... hard to do on a pan.

Post by 03Roadking on Oct 10, 2005, 12:33am

Well we use to have a saying "if it don't stink don't flip it over" I started messing with the float, man did I screw it up :-[ I bent it to far and it ran great till I hit third then it died so I went back and adjusted it some more and then again and again I finale got it set so I can say it's set right Also I made a mistake the keihen I have has 1.65 main and .68 idle I must have got the jet numbers mixed up I was looking a three carbs, anyway I am in the same place as I was last week It will not start unless I let it idle with the gas off before I shut the key off I am looking strongly at CV or S&S

Post by RussW on Oct 10, 2005, 12:53am

Kell, supporting the CV wasn't too difficult. A support from the center case stud to back of the Screaming Eagle air cleaner does most of the job, also made a small bracket to a pan cover bolt to help support from the top as well.


Post by Billy on Oct 10, 2005, 6:55am


A strong carb support's only limits are the guy who's fabbing it..
I have a sharp chrome support (I fabbed) on my Flatty to my SE backing plate. Looks factory.
Rock solid set-up... off my center case bolt..
I'd have to say any carb w/out support is asking for a leak. moco knew this & added the inner backing to be bolted to the evo heads..(simple logic) they don't have problems w/intake leaks...Extremely rare..
My wife's FXDL had 1 go out, but that was after 60,000
miles & (1) mean backfire...

Russ- Nice job!!!!

Post by kell on Oct 11, 2005, 4:28am

I have a support from the center case bolt to my carb, but the carb's center of gravity is not in or near a vertical line with the center case bolt. The strut has to go at an angle to support the weight of the carb. The angled force on the strut is a composite of a vertical force and a horizontal force. The vertical force cancels the weight of the carb -- good -- but now you have a horizontal force on the carb/manifold joint that wasn't there before -- not good. This force is to the right, in other words it is pulling the carb away from the manifold.
I think that's why they put supports to the heads on the newer bikes. The added horizontal force goes the other way, it pulls the carb in against the manifold, all the better.

Post by BillyW on Oct 11, 2005, 8:21am


That's why I mounted to my SE backing plate, much further out past the carb, no problems.

Post by caschnd1 on Oct 11, 2005, 4:18pm


If you use the press-on adapter for your CV carb rather then the adapter that converts your manifold for the stock type rubber grommet connection you won't have a problem with the carb pulling away from the manifold.
I use the support that goes from the air cleaner backing plate to the top-center case bolt and it has worked great with the press-on adapter. Back when I was using the rubber grommet connection I added some springs to help hold the carb in place. This also worked really well. There is a picture of the spring setup here: Image


Post by RussW on Oct 11, 2005, 5:56pm

I do use a rubber spigot adapter to mount my CV, since I made a manifold out of an upswept SU Eliminator manifold I had, cut sections out to tuck carb in close, etc. etc. Craig is right, with the spigot you do need more than just the backing plate brace, thats why I added the bracket to the head as well.

Post by panama on Oct 13, 2005, 7:00am

well duh.

Re: Having Fuel Problems
Post by 03Roadking on Oct 16, 2005, 7:32pm

I pulled the carb off and took it down to the guy I bought it from We took out all his old books on carbs and read each one of them. They all made reference to the Idle jet, Main jet and air screw but not one said anything or pictured a hidden jet or adjustment screw there are two holes or passages that have pressed in caps I really don't want to dig one of them out and wreck the carb. We put in a 1.65 main and I have a .68 idle jet in it but when it's idling you can smell the fuel and it won't start once it's been running for a while, without doing the shut off trick, his only suggestion is a .65 idle jet BUT no one has one. I even took the bowl off of 6 Keihin's he had. Does anyone know where I can get one??? besides
Custom Chrome
I called them and they are back ordered for the last 5 weeks or more
I will call
Old Dude
Way Back Wheels
Fat Dog
Monday morning, Am I missing anyone or does someone have one they want to sell

Post by ozwick on Oct 16, 2005, 8:33pm



Bill's Custom Cycles
7145 Columbia Blvd.
Bloomsburg, PA 17815-8635
Tele: (570) 759-9613 or (570) 759-3078
FAX: (570) 759-9684
E-mail: billm@billscustomcycles.com


Post by ozwick on Oct 16, 2005, 9:01pm

Here is another one

46477 Bursley Road
Wellington, OH 44090
Fax: 440 647 1406
E-mail: info@nosparts.com
WWW: http://www.nosparts.com

27750-72 27750-72 Idle jet 0.65 mm Bendix Sportster, XLH, XLCH late'72-'74. FL, FLH '74-'75. FX, FXE '74-'75. Shovelhead. 22.00

Post by ozwick on Oct 16, 2005, 9:03pm

One more

Jan Willem Boon
Meppelerweg 3
7963 RV Ruinen
The Netherlands
tel +31 (0)522 471177
fax +31 (0)522 473433

27750-72 27750-72 Idle jet 0.65 mm Bendix Sportster, XLH, XLCH late'72-'74. FL, FLH '74-'75. FX, FXE '74-'75. Shovelhead. 28.00

Post by 03Roadking on Oct 17, 2005, 5:32pm

Thank you I have added them to my list. making calls today

Post by fourthgear on Oct 18, 2005, 4:09pm

Hell , try your Bendix out again when ya got a chance. We used to junk them Kiehn carbs because they would do all kinds of weird things on Shovelheads , why do ya think someones got a bunch laying around. An S & S is allot of money but they work and are tunable . It seems some are having good luck with CV s also. If I don't like the way my Linkert works with this rebuild , I will be going to an S&S for sure, we shall see. I just did a leak check and of course its leaking around one of my adapter inserts on my head , if its going to happen, it will, just to slow down progress!

Post by 03Roadking on Oct 18, 2005, 5:21pm

I'm with you on this one I have put out the word looking for the idle jet I have some traveling to do for the next 10 days so when I get back if theres no jet I am going to check my intake for leaks and try the Bendix just for sh**s & Giggles and then I'm going S&S hunting maybe I can find a good price on one

Post by 03Roadking on Nov 10, 2005, 4:39pm

After being sent here and there for the last three weeks I have managed to find time to get back into the garage. I was sitting at my work bench starring at the carb when I noticed the setting for the accelerator pump there are three settings for the spring tension from real tight to loose I noticed if I just touched the butterfly the pump dropped almost a 1/16 of an inch I think that is where my flooding is coming from I took it apart and set the spring for as loose as it would go, Now I have a little play in the throttle before the pump kicks in. I put the carb back on and it fired right up I took it for a short drive shut it off without turning the gas off let it set for a minuet or two then kicked it once and it fired right up I did this all day Saturday stop and start not once did it not start on the first to second kick It still runs rich at an idle and the .65 jet showed up this morning so I will try it this saturday. I think I am gaining on it ;D

Post by Sidecar on Nov 10, 2005, 8:09pm

I can see the smile on your face from here !!!!!!!!

Post by fourthgear on Nov 10, 2005, 8:46pm

Thats a beautiful thing , 03 good luck!

Post by 03Roadking on Nov 14, 2005, 5:24pm

God I hate to be writing this, but I installed the .65 idle jet and the bike won't run. I can get it started but I have to keep twisting the throttle to keep it running I turned the idle screw all the way in and it won't stay running I reset the float to make sure and I tried to adjust the air screw, no matter what I did It just wouldn't run it keeps popping out the carb. I pulled the .65 and replaced it with the old .68, fires right up and runs pretty good So now what??? any suggestions or am I on the road to the S & S store??

Post by fourthgear on Nov 14, 2005, 10:02pm

what is your definition of running pretty good ? If its running 100% better then fuel running out of the carb. you can only get so much out of any stock type carb. Is it you are not satisfied with the performance with that particular carb.? Running pretty good is what scale to you?Are you comparing it with your Roadking? I can feel you know where this is going.

Post by 03Roadking on Nov 15, 2005, 12:51am

I would never compare the Pan to the RK two different animals
What I mean by pretty good is one to two kicks first start of the day no missing or back firing, going from first to fourth very smooth and I can hold it at steady speeds at any gear without lugging, missing or flat spots
But it still gives me trouble starting when it's hot and if you are sitting at an idle you can just smell the raw gas fumes coming from the pipes Is this average or normal?
I downloaded the instructions for the installation and jetting for S & S carbs It had a lot of useful information one Idea I tried and seems to work. it says "if you think the engine is flooded make sure the choke is off roll the throttle open very slowly until its wide open then with the key off kick the bike 6 or 7 times not hard just so it turns over then close the throttle turn the key on crack the throttle a tiny bit and kick it" I have tried this suggestion and it worked three out of three times so far Maybe I'm asking to much of this old engine and I know they like to run fat. I just thought I could lean it out a little more so it would start hot easier.

Post by fourthgear on Nov 15, 2005, 1:18pm

Hard hot starting could be a lot of things , timing ,point adj. ,too much throttle hand , just to name a few. Flat spots could be a lot of things too , cam , carb adj. When adj. timing and points you may have to try diff.adj. from norm to get good starting at both hot & cold . All motors are not the same in these conditions and playing with adj. can have good results. What kind of air filter are you using? Are you adj. carb. with it in place? That starting of a flooded motor with throttle wide open and slowly kicking through is something you need to know when you have a kick start , thats for sure. I open the throttle and leave the switch on and kick it just like I'm starting it and when it pops a couple times , then close it till it is just slightly open and keep kicking till she starts.Just remember if your carb. is putting too much fuel in, any starting technique may not help.

Post by 03Roadking on Nov 16, 2005, 4:31pm

Thanks I am going to go at it this weekend, start with the valves and timing and see what I can come up with some of my friends use to say I was a perfectionist and I use to say no I am a possiblest I want it as good as possible, nothing is perfect ;D

Posts: 3337
Joined: Sat Jun 26, 2010 1:54 pm
Bikes: 1958flh 1969sporty,had a knuckle but sold back to original owner
Location: NEW JERSEY
Has thanked: 195 times
Been thanked: 259 times

Re: Having fuel problems


Post by 58flh » Tue Oct 02, 2012 2:04 pm

I know this is an old post!--But Im going to add, that .065. or .068 is high for a idle to off-idle jet!. And you can plug the jets-up & drill to size you want!--You will still smell that fuel at idle with a .065 jet!-Although you will have a significantly better starting -(easier ) on a hot motor!--You should not have to shut-off your gas & wait for the bowl to empty!. ,To fire it up again when hot!. Those caps as you call them on the Kehien bodies are -(welch-plugs!)--Drill a 1/8 hole & grab it with a drift & pull it out.--You will find ADJ. screws under them!--(Thank the EPA for not letting you tune your own carb.!). This is the REASON for the WELCH-PLUGS!. So guys like us cant turn screws & make them run--RIGHT!---I believe the standard is -(15 to 1). If your KEHIGN has 2 W-Plugs ,1 is for idle & other is MAIN- or hi-speed ADJ. screws!---YES you can regulate the amount of fuel to these carbs. I agree that .068 for idle to off idle is much for a pan!. But it can be regulated to the low-speed jet how much fuel you want in there!. Also you will find when getting less fuel to the .068 jet the bike will IDLE like CRAP!--Start to ADJ. with a .060 jet! & it works awesome!---Leave the main alone & gheck the plugs after you put 20 or so miles on after youve fixed your off-idle problem!. I like little on the rich-side, but not sooty black or wet!, just enuff to still make out a coco-brown on the tip of the insulater. YOU DONT WANT AFTERUN!. This will give you a HEADACHE=(DAMAGE)--in a short amount of time!. NOW the BENDIX with ADJ. mainjet is a way better & trouble free carb. to run!. Its a mindless carb. to set-up just like a S&S!-(read the manual on them & the AHA moment will hit you in the face). For both fixed jet & ADJ. jet Bendix carbs.!---GOOD-LUCK-----RICHIE

Posts: 1896
Joined: Fri May 24, 2002 1:00 am
Bikes: 64FL 99FLHR 01FXSTD
Location: Mpls. MN.
Has thanked: 14 times
Been thanked: 65 times

Re: Having fuel problems


Post by Panacea » Wed Oct 03, 2012 1:36 am

I wonder what happened to those guys, Kell,03roadking,Billy,sidecar,fourthgear. Long time no see!

Site Admin
Posts: 2646
Joined: Wed Dec 12, 2001 9:17 pm
Bikes: 1954 FL
Location: Holland
Has thanked: 13 times
Been thanked: 101 times

Re: Having fuel problems


Post by panhead » Wed Oct 03, 2012 8:59 am

I wonder what happened to those guys, Kell,03roadking,Billy,sidecar,fourthgear.
Me too Panacea. Kell still visits the forum, Fourthgear hasn't been here since May, the others haven't been here a couple of years. And where are King, Jack Hester etc.?

Posts: 3337
Joined: Sat Jun 26, 2010 1:54 pm
Bikes: 1958flh 1969sporty,had a knuckle but sold back to original owner
Location: NEW JERSEY
Has thanked: 195 times
Been thanked: 259 times

Re: Having fuel problems


Post by 58flh » Wed Oct 03, 2012 12:11 pm

KELL was at my house a few months ago!, We got a little something to do & we will be getting together soon!. Ill mention you boyz were askin bout him.----RICHIE 8)

Post Reply

Return to “Carburetor/Fuel system”