1928 JD Motor

[MSkeene]

Hello! My name is Mitchell Skeene and I am 21 years old. I am attending Mount San Antonio College and am studying aeronautics. I am a student pilot and am working towards earning my private pilot license. I just purchased this 1928 JD motor and would love to build it up one day. I have lots of question regarding the engine and about the parts I need to make it complete. I know there are some issues with the motor such as the broken motor mounts and there are a few small cracks in the engine block. I don't know if these are easy repairs? Also I have been considering buying a cam cover for the motor, but I have seen a few variations of cam covers so I am not sure what type I need and what year parts will fit the motor? Any information will help, thanks!

[Rollo]

Mitchell,

Welcome and good luck with what will be a great project. There are plenty of folks on here who are J motor folks and can help with knowledge and parts. I am sure they will chime in shortly and help you get going on your project. I may take a while but don't get discouraged and keep plugging a way even if only a little bit at a time.

Tom (Rollo) Hardy
AMCA# 12766

[exeric]

Welcome Mitchell, I built my '48FL by starting with a pair of gas tanks; and also built a 1920J from the motor, up. Like Tom said, it takes longer, and will probably cost more, but there is a lot of intangible satisfaction to be had from doing that. I've also seen a lot of people who bought complete motorcycles, only to find out everything is mismatched, or worn out. So, now you have the opportunity to do the research to get the right parts, dig through thousands of boxes, and millions of dirty motorcycle parts, at motorcycle meets all over the country. Welcome to our world

[whp]

Mitchell! Good work on buying a JD! It's a bit more unique and fun than anything else I've built that's for sure. Looks like you have a great start to an engine. Those motor mounts are kind of a pain unless the right guy is on the job. They have to line up perfect with the frame so there isn't any torque stress on them once they are bolted in. But like anything, the right fixture with the right aluminum welder can make it happen for sure. You could buy one of the reproduction keystone frames that Period Modified sells too. Those frames mount through the engine bolts I believe. All depends on the direction you want to take. If you have any family members with a mill and a lathe cash in those favors because you'll spend hours jigging up things just to take few thousands out of something to save an original part!

Keep an eye out for a decent set of cylinders, the JDJUGS are nice but were not in my college budget...

That pinion gear is LH thread just in case you don't know.

For the case bolts I took a socket and milled slots out so that they fit into the two holes on the nuts. They are 1/4-24. 24 pitch is rampant all over that bike.

You'll want the cam case that has a little flare inside the case by the generator gear (correct me if I'm wrong). I have a rough one if you need. The cover with the oil feeder is the adjustable, kind of looks like the VL oil pump. But any steel one will do. There's a few guys in the Hells on Wheels MC that have J's. I'm not sure who else does in the LA area.

Good luck and don't loose faith in the J, it'll be worth it.

[Steve Swan]

Hello Mitchell ! Welcome to the forum, it's great to have young folks interested in these old machines. You are in the right place to begin your efforts, there are a tremendous group of very fine and knowledgeable fellows here. i just finished my 1927 JD May 10th, after nearly 4 years and 500+ hours, not including joining and researching this forum, researching available info on internet, collecting/studying literature. i began my project August 10, 2013 with an engine, transmission, frame and front/rear wheel hubs. my LH case had a pair of "V" cracks at the rear lug that extended in to the belly of the case. if you go to "member bike builds," you will find my "27 JD Restoration" thread that will give you an idea of the condition of the parts i started with as well as progress throughout the project. My research of this forum of other member's builds, even non-JD builds was most helpful. i highly encourage you to read and learn everything you can find and ask for help when you need to. as you begin, having a copy of the 1927 and the 1927-31 parts book you will find indispensible. when looking for parts and asking questions, i found it necessary and very helpful for questions i had, to refer to parts numbers and descriptions of the parts as in the factory parts books/literature. EVERY bit of research you do will build the foundation for the successful completion of your project. Know that your engine (and the rest of the bike) will be a piece by piece build, not a simple matter of buying parts and putting them together. At least in my case, every part had to be inspected, then fitted to the part it corresponded to, sometimes spending hours on a single part to make it right. The process is slow going and taught me more patience and perseverance than i sometimes thought possible. Each and every step you complete is one more step towards completion. in my case, to keep myself organized and minimize brain damage, i had plan in advance of starting out and kept a notebook to log the various steps, procedures, aspects i was juggling simultaneously. Another excellent resource is JD Yahoo Groups, i encourage you to join them and introduce yourself there. There are a number guys here who have real passion for things JD. if you go to page 16 of my build thread, you will see the list of people who helped me get my '27 back on the road. all this being said, the first time i stepped on the starter pedal and the engine roared to life was a GREAT MOMENT ! If you click on the link below after my name, you will see the JD on it's 1st trial run, last August.

[MSkeene]

Thank you for the encouragement Eric! I can't wait to get started!

[MSkeene]

Thank you whp! I appreciate the information. Do you have a picture of your cam cover?

[MSkeene]

Steve, thank you for all the information! I have been going through your build pots and I am learning so much from that already. I will definitely get a copy of the 1927-31 parts book. Thank you for all the help and encouragement!

[Steve Swan]

Steve, thank you for all the information! I have been going through your build pots and I am learning so much from that already. I will definitely get a copy of the 1927-31 parts book. Thank you for all the help and encouragement!

Don't hesitate to ask questions, we all learn from what we share. and if you need resource contact info, i have 4 years accumulation and other fellows here know resources i don't know of.

if there is such a thing as a 28 parts book, i would suggest getting a copy to supplement supercessions that may have occurred in the 27-31 book and hence not noted or pictured in the 27-31 book.

attached is a picture of the steel gear covers. the top one with the pyramid shaped notch behind the mechanical oil pump is what your 28 should have. the bottom cover is for earlier models, pre-26 i believe, but i may be wrong.

20160227_202302.jpg

also attached is the earlier gear case which i have in my engine. the later gear case will have the corresponding "pyramid" cast as part of the case. the hole at the rear of the case is where the generator shaft goes through and if a puller isn't used when removing the generator gear, the thin lip of that hole gets broken out.

20160301_144408.jpg

[MSkeene]

Steve, I will start searching for a 28 only parts book. Thank you for the clarification with the pictures! I never noticed the pyramid shape before! From looking at your pictures and other pictures now I can clearly see the difference. Thank you

[Steve Swan]

Steve, I will start searching for a 28 only parts book. Thank you for the clarification with the pictures! I never noticed the pyramid shape before! From looking at your pictures and other pictures now I can clearly see the difference. Thank you

I don't know if there's a 28 only parts book. Those with more experience than I will know. My JD knowledge base is for the most part limited to my experience with my 27.

fwiw, the mechanical oil pump on a 28 is different than shown in 27 pics i posted. The 27-31 parts book will show differences such as these. There are some very helpful factory "Shop Dope" service bulletins and mechanics bulletins available. if you go to JD Yahoo Groups, go to "Files," you will see a link to the 1917 U.S. Army Motorcycle Repairer's Manual. There is also a 1923 factory book titled something like for the "Motorcycle Repair Man," i can't seem to get my hands on my copy, must be at my shop.....

also, this is an informative link i found useful - http://webspace.webring.com/people/qp/pravg/engine.htm

A 1928 Rider's Handbook is also a very good thing to have. When you are ready, i would be happy to copy what i have that may be helpful to you. The AMCA library may have some info you can download. Various JD guys who sell parts also have copies of literature available, Replicant Metals sells the 27-31 parts book. And ebay.

[Steve Swan]

Looking at Tom Feeser's Replicant Metals, i see he has copies available of the 22-28 Parts Book and the 28-32 Parts Book. http://www.replicantmetals.com/library.html

early on, when i was doing my research, i looked for every picture i could find of 26-29 models. fwiw, attached are a couple pics of an unmolested o.p. 28 with a few parts that are not period correct (namely rims and saddle) that sold on ebay or after the auction ended, can't remember which, something like the low or mid $30k range i 'think'. at the time, i contacted the seller and asked him if he would be so kind as to send me pics, he sent me 26 pics.

$T2eC16NHJFoFH4t-WyTCBSZsb+6SDg~~60_57.JPG$(KGrHqYOKnMFJjsGctvWBSZsespDBQ~~60_57.JPG

here's another nice pic of what appears to be a fairly accurately restored 28.

1928 restored.jpg

[Steve Swan]

one of our members with more comprehensive knowledge on things JD would need to say if this pump is correct for 28, i believe there may be differences between the 28 and 29 pumps as well as early and later improved designs in one or both of those years.... but this is the throttle controlled type pump that was first seen on 28 models.

http://www.ebay.com/itm/Harley-David...FZO37U&vxp=mtr

[MSkeene]

Steve, I did look up the Replicant Metals and I plan on ordering the 22-28 and 28-32 parts book. I was looking at that oil pump on eBay! I have also been bidding on some cam covers on eBay but haven't had any luck yet. Thank you for the pictures an all of the help you're giving me! And Happy Fathers Day!

[MSkeene]

Steve, I have been watching this cam cover on eBay. Does it seem to be in good shape? And do you feel that the price is fair?

https://www.ebay.com/itm/261742189578