1963 FLH plug fouling

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obierider
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1963 FLH plug fouling

#1

Post by obierider » Tue Jun 28, 2005 5:42 pm

I restored a '63 FLH and experience severe plug fouling after 15-20 miles. Details of bike are: original M74B, rebuilt twice to address problem (by different rebuilders), all ignition parts, including coils replaced, static timing right on- both cylinders, intake maniford o-rings replaced (but manifold not pressure tested), true dual exhaust, engine rebuilt, several plug heat ranges tried - same result. Bike problems after rebuilding are exactly the same as before. With fresh plugs, bike starts well and runs smooth. Both plugs load up with sooty carbon quickly leading to misfiring. I do not run on choke longer than necessary. Perhaps a clue- high speed needle adjustment appears to have no affect on running performance. Low speed mixture screw is two knicks off speed drop at lean. My next move is to look at fixed jet size. Any suggestions? Thanks



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Re: 1963 FLH plug fouling

#2

Post by PanPal » Tue Jun 28, 2005 6:32 pm

Sounds like she needs the carb leaned out.

obierider
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Re: 1963 FLH plug fouling

#3

Post by obierider » Thu Jun 30, 2005 12:40 pm

Further to my post: I am considering switching the main jet from the #19 (standard) to a #18 or a #17 in an effort to lean out the carb. Any recommendations on this approach?

03Roadking
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Re: 1963 FLH plug fouling

#4

Post by 03Roadking » Thu Jun 30, 2005 2:43 pm

Hello
I have not belonged to this site for very long but I know the expert's here will tell you part of your answer is in your statement (manifold NOT pressure tested) I had the same problem it took a new set of Clamps and O-rings and you must must pressure test it. Without being sure the manifold is sealed, everything you do is a waste of time. Your plugs will read wrong, your carb setting will only last as long as the manifold leak stays the same. If it leaks a little more you will have to re-adjust it if it leaks a little less you have to adjust it, not to mention the damage you can cause if it starts running real lean while your out on the road.
Someone sells a pressure testing kit for your carb here on the site and Cotten has written procedure about it here and on other site's if you do a search here you will find it
Good luck

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Re: 1963 FLH plug fouling

#5

Post by fourthgear » Thu Jun 30, 2005 6:48 pm

03roadking is right on , check for the EVIL MANIFOLD LEAK as they say here and go from there . Cotton should have something to say about the Linkert , he knows them for sure .

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Re: 1963 FLH plug fouling

#6

Post by Cotten » Fri Jul 01, 2005 11:08 am

The leaktesting procedure is at http://virtualindian.org/11techleaktest.html" onclick="window.open(this.href);return false;

Mbskeam offers a complete kit at http://www.geocities.com/mbskeam/index3.html" onclick="window.open(this.href);return false;

After that variable is eliminated, beware of floats that don't: 2496

After that has been cured, beware of resistor plugs or wires.

obierider
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Re: 1963 FLH plug fouling

#7

Post by obierider » Fri Jul 01, 2005 11:16 am

Thanks for all the helpful suggestions. Following the advice, I leak checked the intake manifold and no leaks were found. I have tried two brass floats so far, the first one became gas-fillled and sank, what a surprise! I have a second, allegedly superior brass float from another source. I'm ready to try another solution.

Cotton, can you give me a source? I understand you sell them. Please provide details.

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Re: 1963 FLH plug fouling

#8

Post by Cotten » Sat Jul 02, 2005 12:35 am

One is on the way, ObieRider...

For the rest of the readers: there are two brass floats on the market that I know of...
in Walneck's some are offered at $5.87 each...
but the very finely made ones from India with very little solder that weigh ~3 times and original, yet are prone to leakage and corrosion,...
and the USA made ones look sloppy, weigh four times as much as originals, rarely (if ever) leak, but are even more marginal because of their bodacious mass and volume.

Neither can be set anywhere near book spec and still function properly. When the fuel formulations turned digestive, brass seemed to be the only alternative.

I resorted to the same material that most all automobile manufacturers spec for gastank sending units, and machine them individually so they would service at a 1/4" setting. This makes them expensive, but the last float you should ever require.

65flh5326
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Re: 1963 FLH plug fouling

#9

Post by 65flh5326 » Wed Jul 06, 2005 4:19 am

I had a simular problem with my 65, found that a main jet drilled to .078" solve the problem.

Don

obierider
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Re: 1963 FLH plug fouling

#10

Post by obierider » Tue Aug 02, 2005 12:30 pm

As a folllow-up, first thanks for all the helpful suggestions. I believe I have the problem fixed! The key steps (I think) were:

1) I installed one of Cotton's foam floats and set float height to manual setting (1/4 inch),
2) I pressure tested the intake manifold, and
3) I went to a #17 jet (rather than the #19 specified for the bike). She runs beatifully with quick starts, smooth running and, thankfully, no plug fouling!

58flh
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Re: 1963 FLH plug fouling

#11

Post by 58flh » Sun Jan 16, 2011 2:23 pm

pressure test the manifold seals is a must first move! If everything is well,recheck float-level---then work frm jet-sizes from there. Also what type of cam did you install, that would make a diff. Asuming the rebuild is for street-ridin, recheck the valve-timing-lash! One more ?... does the motor backfire through the carb? also do you get 12guage like blast out the exaust? If everything is in check,then play with your jet-size. Use care not to go too much every-step!(a set of small drill-bits & reamers will get you there) I would go .002 to .003 size increments. A little trick i use when I time my bikes is this-( timinglight is of no use, those plastic see your mark things that you screw into the timing-hole are useless! Do this---- raise the rear wheel off the ground, put bike in 3rd gear, with the rearwheel bring your mark to the center of the hole, if you pass it do not rverse ,go around again until its in center!!! take your dist.cap off. At this point you can use a testlight or voltmeter. Hook up testlight to your points,now advance your pointscam all the way ,if light goes on your timing could be a little early. Do this---loosen the plate screws & turn it until light goes out,all the time holding the pointscam in full advance ,now gently turn it the opposite direction until it lights-up!,lock the plate screws & recheck,due to a little flexing & movement in the plate,you might have to tweak it a little-very little. Once you have proper adj., I have found theres no better way to find true T>D>C>, by using the rearwheel to center the mark in the hole,you take-up all the lash in the geartrain & chains, resulting in a true top dead center! This may sound a little confusing at first, but once you do it 3 or 4 times,it becomes second-nature. I can do mine in about 5 min. while having a cold one! Ive been timing my bike as well as alot of others this way, & with great results. I dryfire my Pan 2 or 3 times depending how cold it is---then hit the ignition & one kick fire! To much rambling already,I hope I helped somebody,especialy the newcomers!!!!! Knees in the breeze-----58flh

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