Topic: Drag Bike / The Big 4 Express.

[Don R]

 I'm taking stock of what the junk performance motors need to be usable. Only requiring a trip to cyclex and $$.

 #1 The 1124 stroker motor needs the sleeves moved to a new properly machined cylinder block and possibly o rings. A pair of the sleeves are low in the cylinder and don't seal to the head.
 #2 The turbo motor needs pistons and sleeves, or a new block bored
 #3 The Hot Rod 836 RC motor wants an 870 (I meant 890) kit since the rings and cylinder are junk and rusty.

[PeWe]

CycleX had low priced sleeves 1-2 years ago. Then raised the prices.
They can hopefully reintroduce a lower price

1 set of 4 $129US.
I bought 1 stepped set for 836-900cc (65-67.5mm bore). 74.2mm outer diam where bored  in cylinder block. 64mm inner at delivery.

Upper case might need a little massage with a Dremel.

And also a set of 74.5 mm outer diameter,  for 970cc (70mm). 69mm inner at delivery.

[RAFster122s]

PeWe what do you mean "inner at delivery"
Are you referring to internal diameter?

[Don R]

 I think it's the ID they come with.
  I think these need early cylinders to keep away from the seal holes near the sleeve's edge.  I may need to take the Hot Rod motor apart for the core to get new sleeves, it's 836 now, I'd like it to be 890 or bigger.

[Don R]

 There's most of a kawasaki ATP kit on ebay in pieces. Even the f turbo charger for 2K. All in it's over 5K and isn't complete.
  I should list my extra stuff and let the market decide the value.

[Terry in Australia]

Good idea Don, I'm waiting for a couple of Gates belts to turn up so I can stick those Kawasaki ARD Magneto's on Ebay, I just sold a CB750 "roller" (good engine loosely mounted in a good frame, with crappy wheels and forks loosely attached just so I could roll it onto an interstate truck) and am in a selling mood, I keep looking at my stocks of good CB750 parts and really want to build a K1 over summer when it's too hot to ride.

[RAFster122s]

Would make a nice nest egg for another purchase or one to just bank for another day or something else...

[Don R]

 I go out to finish work on the f1 and K0 to go, but I always find myself working on the turbo bike.

[Don R]

 ARD Mark II Magneto test, I'd say this puts to rest the rumor that it's not a real magneto. Batteries not included. Spinning the crank with a drill, just a loose case with a crank, oiled and assembly lube on the 3 bearings. It appears to spark two or three times and skip a spark or two, may have to do with my crude test rig.
   I went ahead and ordered two timing belts for it, the mark 1 used the same length belt but the mark II has a narrower pulley on the bottom. This one feels pretty stiff.

https://photos.google.com/photo/AF1QipNNcbR2Sx1snLpw9Sc9-ROd2ZSyGyg2PGfd6ihH

[Don R]

  An Australian guy on FB said he had 2 or 3 ARD mark II caps. He said he would post the part numbers when he got home from vacation. He did, in the post where he wants $80 each. L0L. The web site for that brand doesn't recognize the number. Just my luck.  I still think fiat X19 but there were different distributors and different appearing caps. Magnetti Marelli is one brand of distributor, Bobina is the name on cap I have

[grcamna2]

You've got a few good 'irons in the fire' Don 

[Don R]

 I need to finish off a couple to sell and make $$ and floor space for the Hot Rod stuff. Right now there are no cheap -2" 750 or standard cb550 fork tubes. I hate to pay double for the same product.

[grcamna2]

Do you want to race the drag bike ?

[Terry in Australia]

I hate to pay double for the same product.

Just buy one then?

[Don R]

Do you want to race the drag bike ?

No, I'm planning for it to be a street freak and show bike. I wouldn't build a race bike with so many moving parts. A GS1100E is cheaper and faster. Even my junky kz1100 gets it done.

[Terry in Australia]

Do you want to race the drag bike ?

No, I'm planning for it to be a street freak and show bike. I wouldn't build a race bike with so many moving parts. A GS1100E is cheaper and faster. Even my junky kz1100 gets it done.

Yep, Sammy Green was telling us both on FB about his CB750A based drag bike doing a 7 second 1/8 mile Don, and when I asked Doctor Google what that equated to in the 1/4 mile, it worked out to an 11 second run. Pretty good for a CB750, but the ‘99 Fireblade that I paid $2500 ($1600 USD) for does the 1/4 in 10 seconds off the showroom floor.

[Don R]

 The 1124 stroker motor I started this thread with has its issues and the popular opinion is that it will break at some point. I still want it running too but I ain't brave enough to spend the $$ when there's a car project sitting here unfinished. 

[Don R]

The turbo frame is raked 6 degrees over stock and with the 550 forks up an inch in the trees and the +3" swingarm it has a 62" wheelbase which is around 6" over.
 I'm lowering a set of 750 F0 forks 2" with spring spacers just to see how much travel it will have. I'm interested in fork travel and how low it can go without bottoming out in normal riding. I realize I won't be able to take potholes at speed but it isn't for that kind of riding anyway.
 The K3-4 forks have bigger internal tubes than the F forks. I made 2" long tubing spacers to fit the K forks but they don't fit the F forks so I cut 2" sections off an old fork spring to add to the F fork. 
 The pipefitter in me wants to cut down the early +6" Franks forks I have to make them -2" I could put the weld in the headlight mount so it wouldn't be seen. Both of the late type +6" forks I have had bad gouges in the seal area.

[Don R]

  I got a set of F forks cleaned, resealed and shortened 2" by cutting the spring and putting the cut piece under the internal spring that limits up travel. It will be interesting to compare this to the 550 fork travel wise.

[BenelliSEI]

The math says cutting the spring will make the remainder stiffer, but it’s so long to start with it might be negligible. Won’t this mod just decrease your travel by 2”?

Attached a picture of a bike I picked up a few years ago. Supposedly built by Orient Express shop in the late 70’s. Ran a pair of 40DCOE Weber carbs.

[Don R]

 Yes, it will reduce travel but also shortens the resting height of the fork. I also lowered an early fork 1 1/2" by stacking an extra set of bronze bushings with the flange cut off.
  I'm not sure if/when Emgo is going to make more replacement fork tubes, the supply seems to be drying up. The prices are rising and they are scarcer with web sites showing out of stock and no idea when they will have more. Forks by Frank may see a rise in business.

[Don R]

 I had to roll it off the lift, it got dark out so I got a pic inside.

[grcamna2]

I had to roll it off the lift, it got dark out so I got a pic inside.

Looks like a decent platform Don.

[Don R]

 Thanks, packaging the fuel pump, ignition box, coil, turbocharger and charging system are the challenge here. Something will need to go under the battery box.  The frame mod squeezes the coil area.
 The ign. coil and CD box are on a mount but I'm unable to visualize where it was previously mounted.

[Don R]

 I learned the F, A and late K tall fork lowers have different inside valves and parts than the 550K 341  and 750K 341 type forks.
 I bought the last set of 21 13/16" long fork tubes in captivity, they fit the 341 type fork legs and should make more travel then the F0 forks lowered