Newbie Harley J Questions

[TechNoir]

Hello, a few of you may know that I am rebuilding a Harley Davidson 20F that I have a build thread for in the Projects section.

Well I am a bit behind on the build thread and in reality I have got to the point where the bike runs.

I started it yesterday for the first time and took it up the road, only about a mile or so, but it was the scariest mile I have ridden in a long time, mainly because the clutch and gear change were totally out of adjustment. I have adjusted those items now and done a few other jobs and did a couple more miles today. ( I cant ride it too much because I am waiting for some paperwork in the post to make it 100% legal but it has a numberplate and is insured so I figured that a quick run up my lane wouldn’t hurt)

Bike yesterday evening.




I need to sort out 2 things which are my "Newbie Questions"

Question 1. I need to sort out the fuelling. Other than the owners manual, is there a good guide to tuning a Schebler carburettor? Online or in print I dont mind which. They seem fairly simple but I also assume that they have their quirks.

Question 2. The bike is burning too much oil and I need some advice. I have never had anything with a total loss oiling system before so I am a bit in the dark on what is OK and what is not OK. I have read the manual and it says that after flushing the engine you need to fill the crankcase with 2 hand pumps of oil. Is this correct or too much or not enough?

When I took the bike up the road and back the first time the bike was smoky. I was not too concerned because I had put some oil in the bores and turned it over loads of times so I was expecting smoke. However today, after I had adjusted the controls I took it out for a 2 mile ride and it is still very smoky. It is also spewing oil out from, I think, around the spark plugs so I definitely think there is an oil problem (I guess it is better than no oil). So how much oil should there be in the sump after a ride? Also I know that with no oil ring the bike will burn some oil, how much oil do they burn? At the moment it is smokier than a 1970's 2 stroke. It is worse at idle than when moving.

How do you check the oil pump feed rate? Is it just run it, drain the sump, adjust the pump, run it again etc until you get the right adjustment? Also, where do I get the oil pump shims from or do I need to make my own?

I didnt have the engine apart after the Bill Healing rebuild so it could be a gummed up ring or rings but before I tear it apart I would like to seek the opinion of more knowledgeable and experienced on Harley J's on this forum.










Thanks

John

[Steve Slocombe]

Dear John, nice looking bike and don't start tearing down a rebuilt engine quite yet. The handbook should be good for Schebler start-up. For the similar Linkert you start by turning both needles right in then two turns out. The low speed (rear) needle can be turned in and out an eighth or quarter turn at a time until a hot engine ticks over without hunting or missing. The high speed needle can then be taken in a click or two at a time after fast runs and spark plug checks. A shade rich is better than too lean.

The once-through oiling system was used right up to 1936 and needs dialling-in over a couple of hundred miles. The idea is to keep about five or six ounces, say 150 ml, of oil in the cases at start and finish of a run. Drain the cases, three pumps of oil, go for a ten mile run, drain cases, three pumps of oil, twenty mile run, drain cases, fifty mile run etc etc. Adjust the mechanical pump as needed, buying or making shims as necessary. The hand oil pump may drain past the check valve, so a bike left a week may have a lot of oil in the cases. Remove hand oil pump, refurbish check ball and seat etc. Your smoky motor may be because of rich mixture or too much oil in the cases. Keep at it.

[TechNoir]

Re: Newbie Harley J Questions

Steve, thanks for the reply. That was exactly what I needed especially the advice regarding getting the oil right. .

Now I need to wait for road tax. I, stupidly, assumed that I could tax it online because I have a V5 but the computer said no. So I called the DVLA and they said it was postal only because it hasn't been taxed for so long and it isn't on their records as being SORN either. (I have a tax disc dated in the 1930's which I think was the last time it was on the road)

Once it is fully legal I can get some miles on it and get it running right.

Thanks again.

John

[T. Cotten]

John!

Of course, your HX Schebler only has one needle.
I reviewed your project thread, and see the carb was attended to thoroughly, but several years ago:

"After cleaning out, found to be worn on butterfly spindle, also distorted & worn butterfly valve. Replacement spindle fabricated & carb body re-bored to suit, replacement butterfly made up. Spindle is now modified to take a screw retained butterfly (rather than old soldered in type). New air balance valve & spindle assembly made up & seating machined to suit. Replacement high speed air flap made up also spindle for the same. All other parts cleaned up & re-shaped or replaced as required. Main body components blasted to remove verdigris prior to plating with other parts."

I must say the plating is far more authentic than any of the USA processes that have crossed my benches!

If by 'high speed air flap" you mean the spring-loaded airvalve in the front of it, and a traditional leather seal was used, you may want to moisten it well with fuel before attempting to tune the machine, as it will otherwise change in duty. (Modern rebuilders are turning to teflon or other modern materials, since often these machines see sporadic use.)
The spindle knob usually has steps where it can be pulled out upon a pin stop to hold it shut for starting, without changing the position of the adjusting screw beneath it.
Usually a good place to begin with is to have the adjusting screw in the middle of its travel. Turning the screw inward lowers the RPM where the airvalve will open, outward increases it. After the machine has started and warmed a little at idle, the knob can be taken off of the pin stop, and the airvalve adjusted.

The high-speed auxilliary valve, meaning the thumbtab gate valve on the side, probably shouldn't be messed with until the motor has been limbered up enough for highspeeds.

Your other adjustments are the needle itself, tuning the overall fuel flow, and the throttle cam upon which the needle lift lever rides, which tunes for change in throttle opening.
The only way I know of determining a starting place for the needle is to have the carb and bowl removed, and actually suck upon the bowlstem. Otherwise, because of the spring in the knob, one cannot tell when it is fully shut, or just beginning to open.

The idle screw on the side can be turned all the way in, and its gap to the throttle disc (or 'butterfly') observed with the airvalve removed. If the gap to the fresh disc allows too much air, you will have to add too much fuel to slow the idle. This also applies to any gap around the disc, or at the friction washer at the top of the disc.
Ideally, the screw must be backed out a bit for a strong idle, of course.

Beware also of very heavy floats on the market.

But frankly, a more common reason to run overly rich is because of a vacuum leak at the manifold assembly, and the machine requires too much fuel to run at all.
Have you bubble-tested your assembly?

.....Cotten

[TechNoir]

Cotten, thanks very much for your very informative reply re the carb. The "high speed air flap" is a quote from Bill Healing who rebuilt the carb in 1989 so I would have to assume that your interpretation is correct. I will check what material it is and moisten it.

The float is a cork one. I am not sure if that’s good or bad but it seems to work and seems to at the correct adjustment.

I will take the carb off and make your suggested checks and adjustments and then put some miles on the bike and tune it.

Thanks again for your great response. The time that you and Steve have taken to help me out is very much appreciated.

John

[TechNoir]

Have you bubble-tested your assembly?

I forgot to say that no I haven't yet. I am assuming that you mean testing the manifold for air leaks when you say "bubble test"

John

[kiwi tibbs]

Looking great John,

treat us with a video of her running.

Cheers
Tony

[pulling38]

Hello.
I too am a newbie to this site and the world of old Bike's. I am in the process of getting my 1918 J running. I have only had the bike about 4 months and am in the process of going from front to back checking everything on the bike. It was put together for show but not to run, so I intend to get her running. Have the motor apart now flywheels off to get balance checked. It had a fresh bore with 50 over aluminum pistons but was never started. Have sent the mag of for rebuild. And rebuilt the carb. So still have a ways to go to get her on the road again. This thread has been a big help with a lot of the same questions i would be asking myself. So I also thank all the people giving advice to the other Newbie cause it has been a great help to me as well. I would post some picks of mine but am so new I can't figure it out and I'm not to good with computers. Any help on posting pic's would be appreciated. Thanks Mike

[pulling38]

IMG_20160804_154138852.jpgIMG_20160804_170632886.jpgIMG_20160805_112221615_HDR.jpg These are a few pic's I hope work of what it looked like before I tore it apart and parcial tear down. Its in a million pieces now. Very glad I tore it down have found alot of broken and missing parts. Thanks Mike

[TechNoir]

Hello Mike. Thanks for your comments and good luck with your 18J. I am glad that my posts have been of help to you.


Can I suggest that you put an introduction in the introductions section. Also think about starting a new thread in either the Bike Builds or the J/JD section with lots of pictures.

Good luck with your build.

John

[pulling38]

Hey John.
Thanks for your thread, sorry i wondered if I should start a new thread. I didn't mean to intrude on your thread was just excited to see your bike and wanted to show you guy's mine. I will start a new thread. Not sure how to do the introduction part but will try surfing around and try and figure it out. Thanks so much and best of luck on fine tuning your bike it is a great piece of history. Mike

[TechNoir]

Hey John.
Thanks for your thread, sorry i wondered if I should start a new thread. I didn't mean to intrude on your thread was just excited to see your bike and wanted to show you guy's mine. I will start a new thread. Not sure how to do the introduction part but will try surfing around and try and figure it out. Thanks so much and best of luck on fine tuning your bike it is a great piece of history. Mike

Mike, no need to apologise, I am happy for you to post in this thread but I just thought an intro would let us know who you are, where you are what your experience is etc.

A new thread about your bike would mean that any questions or pictures that you post would all be in one place,

John

[exeric]

Don't worry about it, Mike. Like John said, a new thread for your bike will provide a place for you to ask specific questions, and post updates on your progress. Projects tend to drag on (if you're like me) so it's nice to have a place that is devoted to your bike. Welcome to the AMCA.