Belt Driven Primary
- Thread starter nhstomper
- Start date
Mr. Wright
Knows some things
#1 the Ultima open primary will not fit a Big Dog.
That being said, I am running a Ultima 3'' open primary on my 03 chopper. There are 3 or 4 modification you need to do to it to make it fit.
And yes, my first time out I drug it. Is your kick stand in front of the primary or behind it? Mine is in front, and I made an extinction tab for it so it will hit first, so I know when I getting close now. If you are as cheep as I am, and determined to run the Ultima, I'll post what you need to do to make it fit. Let me know.
That being said, I am running a Ultima 3'' open primary on my 03 chopper. There are 3 or 4 modification you need to do to it to make it fit.
And yes, my first time out I drug it. Is your kick stand in front of the primary or behind it? Mine is in front, and I made an extinction tab for it so it will hit first, so I know when I getting close now. If you are as cheep as I am, and determined to run the Ultima, I'll post what you need to do to make it fit. Let me know.
Mr. Wright
Knows some things
Here's a picture, this is before I added the tab to the kick stand.
Attachments
My kick stand is behind the primary. This is the one I was looking at. Says it fits Big Dog Hard tails 05 and under.
Ultima Open Belt Drive for Titan Big Dog Iron Horse Softail Hardtail Frames | eBay
Ultima Open Belt Drive for Titan Big Dog Iron Horse Softail Hardtail Frames | eBay
H-fred biker
Active Member
I think, don't do it, better look without belt primary !
Mr. Wright
Knows some things
Yea they told me it would fit also. If your going to go for it, get it with the outer support bearing. Two reasons, 1. it will put less strain on your engine and trans bearing, and 2. that outer cover will help you keep your pant leg out of it.
So you are saying I should get the one like you have in your picture? The one I posted the link to is missing the outer support bearing and thats why its cheaper correct? I am going to get one probably in the fall to install over the winter. My bike needs a new clutch anyway so I figure I might as well go that route. If you could please let me know what else I would need to make it fit.Thanks for your input. I appreciate it.
Mr. Wright
Knows some things
You can go any way you would like. I sent you a PM with my phone # if you want to get into more details about it, but here is a write up I did on it, and some pics.
Modifications to adapt the Ultima Evo open primary to a 04 and older Big Dog.
No matter what they tell you, the Ultima Evo open primary, will not fit a Big Dog. Unless your willing to do a few modifications.
I'm not going to give you exact numbers, because I don't know if your bike is set up exactly like mine.
Follow the instructions sheet that comes with it, but you will need a few more pieces, and you will need to modify a few pieces.
When you get the primary, you will also need to get:
1. Engine crank seal
2. Transmission seal
3. Inch and a half adapter, for the engine belt pulley
4. Inch and a half spacer, to go between the backer plate and the engine.
Do not loosen the engine or transmission mounting bolts! Remove the old primary, clutch, chain, gears and backer plate.
Clean the trans and engine good, remove the cover over the alternator and clean with an electronic spray, the coils hold a lot of oil. I did not do this, and when the coils heated up, I thought I had an oil leak.
Replace the trans and engine seals, flipping the engine seal the opposite way you took it out. You are now trying to keep the oil in the engine, not the primary oil out.
You will also need to remove a collar off the trans input shaft. I think it will tell you to do this in the instructions.
Bolt the new backer plate, that you have prepared according to the instructions, to the trans without the engine spacer. Measure the gap between the backer plate and the engine. Mine was 1 3/8". The engine spacer will need to be machined to the thickness of your measurement. After this is done, bolt the backer plate with the spacer and snug all the bolts. NO LOCKTIGHT AT THE POINT. This is just fitting everything together.
Take your new clutch basket and an air motor with a sanding disk, and knock down all the sharp edges on the back side of the flywheel teeth. This will help the starter engage a little better when you go to start it.
Now slide your new clutch basket onto the trans shaft. On mine, it bottomed out on the spines, and did not touch against the bearing spacer that the seal rides on. This is because the main shaft in the trans is bigger than that which Harley uses. The spines are the same, just the shaft is bigger. How I could tell this is because the flywheel teeth did not go all the way into the recess of the backer plate.
Pull the center hub out of the clutch basket, this way you can measure the gap between the hub and spacer, and measure the diameter of the shaft, and then have the hub bored accordingly.
Now with the hub bored, slide it back on the shaft. You will notice that the spines are now sticking through the front of the hub. Take the supplied flat washer, that is suppose to go on next, and trim the center out, so it will fit over the spines. Check to see if that washer is taller than the spines sticking out. I used two washers on mine, just to make sure. Now remove the hub and reinstall it back in the clutch basket and install it back on the trans shaft.
If you bought the OP with the outer support bearings, which I highly recommend. Install the caps on the hubs with a couple of bolts each, then install the outer bearing bracket and check all your clearances. If it all looks good, disassemble and reassemble with lock tight, torque everything to spec’s.
One note here: I had a squeaky rattle that wasn't the clutch disks. When I pulled the outer support bearing plate back off, I found that the inner races in the bearings had been spinning on the spud caps. I reassembled using blue locktight on the inner races, and that noise went away.
The starter jack shaft all went together good, but don't forget to put some locktight on the long bolt that holds it on the starter, mine came loose. And don't forget to put grease in the cap that holds the end of the jack shaft.
The only thing I wasn't happy about was the fact that the Ultima OP is made from recycled aluminum cans, and it does not have the luster and hardness of the rest of the billet on my bike, so it scratches easily.
I'm running the 3 3/8" wide belt, and I've already drug it on the ground. So I made an extension tab for my kickstand, so it will hit first, to keep me from doing it again. On the 04's with the rear mounted kickstand, this won't work.
First pic shows the flywheel not going all the way in.
Second pic shows the engine spacer I had to cut down. They told me that it only came in 1 1/4'' and 1 1/2''
Third pic shows the back of the clutch basket hub machined out.
Forth pic shows the splines sticking out the front.
Fifth pic shows the washer machined to fit over the splines, mine was thick enough, but I used a second washer on top of that one
Modifications to adapt the Ultima Evo open primary to a 04 and older Big Dog.
No matter what they tell you, the Ultima Evo open primary, will not fit a Big Dog. Unless your willing to do a few modifications.
I'm not going to give you exact numbers, because I don't know if your bike is set up exactly like mine.
Follow the instructions sheet that comes with it, but you will need a few more pieces, and you will need to modify a few pieces.
When you get the primary, you will also need to get:
1. Engine crank seal
2. Transmission seal
3. Inch and a half adapter, for the engine belt pulley
4. Inch and a half spacer, to go between the backer plate and the engine.
Do not loosen the engine or transmission mounting bolts! Remove the old primary, clutch, chain, gears and backer plate.
Clean the trans and engine good, remove the cover over the alternator and clean with an electronic spray, the coils hold a lot of oil. I did not do this, and when the coils heated up, I thought I had an oil leak.
Replace the trans and engine seals, flipping the engine seal the opposite way you took it out. You are now trying to keep the oil in the engine, not the primary oil out.
You will also need to remove a collar off the trans input shaft. I think it will tell you to do this in the instructions.
Bolt the new backer plate, that you have prepared according to the instructions, to the trans without the engine spacer. Measure the gap between the backer plate and the engine. Mine was 1 3/8". The engine spacer will need to be machined to the thickness of your measurement. After this is done, bolt the backer plate with the spacer and snug all the bolts. NO LOCKTIGHT AT THE POINT. This is just fitting everything together.
Take your new clutch basket and an air motor with a sanding disk, and knock down all the sharp edges on the back side of the flywheel teeth. This will help the starter engage a little better when you go to start it.
Now slide your new clutch basket onto the trans shaft. On mine, it bottomed out on the spines, and did not touch against the bearing spacer that the seal rides on. This is because the main shaft in the trans is bigger than that which Harley uses. The spines are the same, just the shaft is bigger. How I could tell this is because the flywheel teeth did not go all the way into the recess of the backer plate.
Pull the center hub out of the clutch basket, this way you can measure the gap between the hub and spacer, and measure the diameter of the shaft, and then have the hub bored accordingly.
Now with the hub bored, slide it back on the shaft. You will notice that the spines are now sticking through the front of the hub. Take the supplied flat washer, that is suppose to go on next, and trim the center out, so it will fit over the spines. Check to see if that washer is taller than the spines sticking out. I used two washers on mine, just to make sure. Now remove the hub and reinstall it back in the clutch basket and install it back on the trans shaft.
If you bought the OP with the outer support bearings, which I highly recommend. Install the caps on the hubs with a couple of bolts each, then install the outer bearing bracket and check all your clearances. If it all looks good, disassemble and reassemble with lock tight, torque everything to spec’s.
One note here: I had a squeaky rattle that wasn't the clutch disks. When I pulled the outer support bearing plate back off, I found that the inner races in the bearings had been spinning on the spud caps. I reassembled using blue locktight on the inner races, and that noise went away.
The starter jack shaft all went together good, but don't forget to put some locktight on the long bolt that holds it on the starter, mine came loose. And don't forget to put grease in the cap that holds the end of the jack shaft.
The only thing I wasn't happy about was the fact that the Ultima OP is made from recycled aluminum cans, and it does not have the luster and hardness of the rest of the billet on my bike, so it scratches easily.
I'm running the 3 3/8" wide belt, and I've already drug it on the ground. So I made an extension tab for my kickstand, so it will hit first, to keep me from doing it again. On the 04's with the rear mounted kickstand, this won't work.
First pic shows the flywheel not going all the way in.
Second pic shows the engine spacer I had to cut down. They told me that it only came in 1 1/4'' and 1 1/2''
Third pic shows the back of the clutch basket hub machined out.
Forth pic shows the splines sticking out the front.
Fifth pic shows the washer machined to fit over the splines, mine was thick enough, but I used a second washer on top of that one
Attachments
Last edited:
Mr. Wright
Knows some things
First pic shows the spacing on everything is right.
And the next two are just showing it off.
Give me a call if you need more info.
573-247-3508
And the next two are just showing it off.
Give me a call if you need more info.
573-247-3508
Attachments
BadDawg Bill
Well-Known Member
I just bought this one for mine:
Ultima Drag Belt Drive for Harley Davidson Primary Titan Big Dog Iron Horse CMC | eBay
If I can get my bike started it will be put on Wed. I'll let ya know. I know they had to order 1 1/2 spacers.
Ultima Drag Belt Drive for Harley Davidson Primary Titan Big Dog Iron Horse CMC | eBay
If I can get my bike started it will be put on Wed. I'll let ya know. I know they had to order 1 1/2 spacers.
Mr. Wright
Knows some things
I just thought of some thing else, I didn.t like the springs that came with the clutch, they felt squashy, so I got the next size heavier springs.
WOW! Seems like a lot of extra work has to go into making that set up work on a Big Dog. Thank you Shannon for your time and doing the write up and sharing the pics. Im going to think twice about doing this because Im not that mechanically inclined and Im pretty sure the shops around here wouldnt figure all that stuff out correctly. Again thank you and if I do decide to do it and I need more info I will call.
Mr. Wright
Knows some things
Hey Troy, lets see a picture of that 4''.
BadDawg Bill
Well-Known Member
Don't let it overwhelm ya. It's a 4 Hr job. The only extra parts are the offset collar and extended nut. I put 2 BDL drives on my other bikes but now I don't have a gear/sleeve puller and an extra set of hands to do it so I'm letting Scooters Performance do it. $320 is worth the time it would take me.
I dont really have my heart set on a particular brand as much as I just want one that fits correctly without too much friggin around. You guys that are posting pics mostly have rear suspensions.. I have a 10 year old rigid and I dont know if that makes a difference or not with fitment. I like the one Semi has if I could only look at the bike pic longer than his profile pic. 