Dong Fang DF 250 RTB Bobber Information

[bowtiewagon]

O.k. guys, I need a little terminology lesson today.
what is the proper term for these?

to be more precise, the black bushing looking things that the studs which hold the sprocket into place. I have noticed I need to replace my sprocket yet again as it is not seating the chain correctly, and I want to replace the studs as well. trouble is the home mode studs I created I had to drill the centers of these "bushings" out to get them to fit. Now I know that the new replacements studs will be smaller, and I would like to replace these "bushings". I also noticed they are a bit cracked and dry rotted so to speak. I have no idea the proper name for them to hunt them down.
Also I know there was a post a while back with the correct studs info, I cannot seem to find it. I believe they are Honda studs, which worked.
Thirdly, and I know I am asking a lot, but I do not like the sprocket problem. I need to purchase a new one, but I am not going with the same place I went with before, old bike barn. I do not know why the chain would not seat correctly, but I do not want to take a chance on the same problem happening again, so a lead on an alternate place of purchase would be cool.
Bike is up to 9975 miles at this time, but sitting in the garage without a sprocket has me buggin a little. I want to hit that 10,000 mile mark as soon as possible. Thanks.

[axa]

O.k. guys, I need a little terminology lesson today.
what is the proper term for these?

to be more precise, the black bushing looking things that the studs which hold the sprocket into place. I have noticed I need to replace my sprocket yet again as it is not seating the chain correctly, and I want to replace the studs as well. trouble is the home mode studs I created I had to drill the centers of these "bushings" out to get them to fit. Now I know that the new replacements studs will be smaller, and I would like to replace these "bushings". I also noticed they are a bit cracked and dry rotted so to speak. I have no idea the proper name for them to hunt them down.
Also I know there was a post a while back with the correct studs info, I cannot seem to find it. I believe they are Honda studs, which worked.
Thirdly, and I know I am asking a lot, but I do not like the sprocket problem. I need to purchase a new one, but I am not going with the same place I went with before, old bike barn. I do not know why the chain would not seat correctly, but I do not want to take a chance on the same problem happening again, so a lead on an alternate place of purchase would be cool.
Bike is up to 9975 miles at this time, but sitting in the garage without a sprocket has me buggin a little. I want to hit that 10,000 mile mark as soon as possible. Thanks.

id call them cush drive bushings. google it.

the problem is not with the sprocket at all, the JTR279.xx sprockets are made as they are meant to be. the problem is with our bikes using a rear axle spacing that fit the original sprocket.
If you carefully measure you will realize that the original sprocket would sit very close to .055 mil further from wheel center. Therefore when replacing with this JTR part, you need to compensate for that with a shim placed in between the sprocket and the hub.

Now most people don't even compensate for this so perhaps your problem is a combination of things or something else entirely.

I have no idea why people shop at oldbike barn, your paying near double for the same product. Here the JTR279.30 tooth im considering, $17.51 shipped from amazon.

As for your 10k mark problem, i have a solution for that too. Jack up your bike and spin the front wheel... i calculate a billion and one turn and you ready to hit that mark.

[Babyswiss]

Bowtiewagon: Congrats on the mileage, but looking at those spokes they look closer to 100,000 miles!!! Is that just road grime or are they rusting that bad? Makes me glad mine has never seen any moisture!

[barnone]

bowtiewagon,
The problem might be a worn out chain and not the sprocket. Would you post a photo of your sprocket and chain?
The original chain is not the best quality and if it not taken off, cleaned and soaked in oil frequently it will wear quickly. A high quality o-ring chain will last longer.
BTW, the JT sprockets are good quality.

$(KGrHqFHJEoE88d-iMCKBPS)K0LkW!~~60_12.JPG

[Chi town]

Hey Barone,
How many turns are you at with the air/fuel screw with the 42 pilot jet?

[DanDaMan]

IMO - change front AND rear sprocket AND chain , to the 428 HD chain , its a lighter chain thus adding a tiny bit more zip and we all know these need all the zip they can get

plus it allows a bigger front sprocket , up to a 17

10k miles I think they have served u well im only at about 6k

[barnone]

Hey Barone,
How many turns are you at with the air/fuel screw with the 42 pilot jet?

Don't know, I use a Harmonizer to set the mixture screw. The idea is to set the screw at max idle RPM and "Hg with the instrument.

IMG_2118.JPG

I'll have to turn it in and count the turns. Maybe 2 turns out?

http://www.advrider.com/forums/showt...ght=Harmonizer

Gotta go to the saw mill and help saw some Black Locust logs for new timbers for my bridge this morning so it will be later to get back to you.

IMG_1263.jpg
Some of the decking is rotten which is not good.

[bowtiewagon]

Bowtiewagon: Congrats on the mileage, but looking at those spokes they look closer to 100,000 miles!!! Is that just road grime or are they rusting that bad? Makes me glad mine has never seen any moisture!

A little of both as for the looks of the wheel.It is a daily rider, rain or shine. Not a show bike. It gets me around, and it looks cool doing it.

[bowtiewagon]

I think I found the part number for the Cush drive bushings,
41241-307-010. Not 100% yet, have to measure the ones on the bike first. But they match with the part number for the studs that Barnone gave me 90128-382-670.

[axa]

Anyone think I should buy a tachometer? Will a tachometer make tuning easier for me and more precise?
I haven't had any success in tuning the carburetor. It seems I can never get it right.

They do help clarify things a bit. Humans are so subjective, at least this will give you some factual based feedback when you are dealing with and talking about your engine speed...