650 Mod's 78 Fighter Build

Looking good in those pics, Devine! What kind of work are you doing to the engine, I don't recall from earlier in the thread if you said? I would like to see your passenger peg setup, I neglected to address that issue before painting and now I'm befuddled as to how I will attach a pair without stripping too much, I like the bung option.

Thanks, Zed! As for engine work- I did all that two years ago. When I picked the bike up, it needed valve work, and the rings were fairly cooked. So I did a full top end rebuild, and bored it to the Wiseco 720cc big bore kit. Stage 3 Dyna Jet carb kit, pod filters, and a 4-1 exhaust off a 2001 Kawi ZR-7s (uses the same head as our bikes). Those bikes are still air cooled too, So the exhaust slaps right in,

As for the pegs- when I get to that part, I'll for sure put pics up. I'm hoping to be able to just weld the bungs to the frame in the required spot and call it quits there. Hopefully I can do the same with the driver rearsets too...

Pics will follow all work

650mod wrote: Doug,

I really appreciate that! I'll let you know what I'm able to find today. I'll get the threads checked at this last shop to double check and hopefully they have something in stock for me. How many bungs do you have left?

Thanks Doug.

Devin

I checked and I have 4 "long" M8 bungs. They are 1.125" long, 0.75" in diameter, and are threaded for M8x1.25 bolts. I have two M10 bungs with the same outside dimensions. I had four short M8's but used them on my GPz.

Later, Doug

Doug- The bolts I have are M8's. I wasn't able to get anything in town, but I do have access to a lathe to work with... I'll talk to my friend tomorrow and see what he's thinking for making some up. I'll keep ya posted.

Devin

650mod wrote: Doug- The bolts I have are M8's. I wasn't able to get anything in town, but I do have access to a lathe to work with... I'll talk to my friend tomorrow and see what he's thinking for making some up. I'll keep ya posted.

Devin

Should take you about 15 mins to make four bungs. They're a great beginner project to learn how to use a lathe.

Later, Doug

We'll have to make 8 up, which won't take long. 4 for my front sets, 4 for the rear.

I've run it before, but this will be good practice

So I decided to scrap the metric coupler bolt idea and switch things over to standard. I picked up some nice counter sunk socket head stainless bolts to use for the foot rests. The only issue is... I can't get coupler bolts in a black oxide mild steel. Solution? I'm going to take some 5/8" solid bar, drill the center out, and tap it to take the bolt. Sometimes, it takes a little creativity to get the job done.

Hopefully I'll be in the shop next week to get the sprocket done. One step at a time...

Does anyone know how to lock the drive sprocket into the lathe when machining the outer sprocket? ie the sprocket that will be driving the chain? Due to the teeth on the sprocket, I'm just wondering how I can lock it in so I know it's true and won't wind out. This is the sprocket that we'll be machining the centre out of to slip over the outer diameter of the offset tube.

Thanks guys

Alright. So we got a bit more done today. We almost got the offset fully finished up, but ran into a clearance issue before we went to tack the sprocket together. I'm scraping the frame a slight little bit just above the swingarm. We're going to get this sorted out tomorrow- shave down the cush drive hub a little bit to give me the needed clearance.

First up- the inner sprocket all machined down and welded into the tube. We didn't torch the outer edge off of the sprocket, so it took a little longer to machine down. Thanks to Leon with the genius mandrel idea- I took a hex cap bolt and machined the head of it down to accept the ID of the sprocket. Locked it down with the nut, and we're good to go.


The drive sprocket locked into the lathe to get opened up.


All machined and slipped over the tube.


Cut the tube length down a little so we could lock the sprocket in place. Chain locked on, time to give it a spin.


A quick peek at the frame clearance. As you can see, using the O-ring chain was probably not the best idea. It's a little wider, so it scrapes a little but. It's not too bad, but definitely needs to be fixed. Off to the lathe with the cush drive to get spun down a little...


Having the chain on the bike really gives a good idea of how much longer the wheelbase now is. I believe it's 4.5" over the stock wheelbase.


As you can see, the rivet is JUST brushing the frame welds- this is right above where the foot rest is welded in.


One more quick peek. I think that an eighth of an inch should make for plenty of room on the frame and tire side. More pictures will be up with the progress from tomorrow's work.


ALMOST there.... Finish the sprocket up, then get the steering stops and foot rest mounts welded in. One more thing to check off the list of things to do...

really nice work!

glad i could help,

leon

So I still have a little clearance issue after shaving 1/8th off the cush drive hub. I've got plenty of meat left there, and can easily take 1/16th-1/8th more off right now.

Chain to tire clearance right now is 1/8th. I'm running an O-ring chain (which I know wasn't the smartest idea).

I'm thinking of changing back to a standard 530 non-O-ring chain to gain 1/16th clearance (ish) and then shaving another 1/16th off the cush drive. Clearance to the frame right now is rubbing (but only slightly). I think if I combine these two savings to get 1/8th I should be ok.

Input? I'd like to avoid notching the frame if possible.

Devin

I might have missed it in earlier posts but is that a 520 or 530 o-ring chain?