Author Topic: Drag Bike / The Big 4 Express. (Read 65870 times)

Don R · « **Reply #125 on:** August 07, 2016, 07:40:47 PM »

Thanks Bill, I'll check it out. I'm sure the belt isn't timed right, with the engine at TDC the mark on the drive case doesn't line up with the mark on the pulley. If I get that right the rotor should be set at 35* on #1.
I filed the points, re-set the gap and now it makes a pretty good spark when turned with a drill motor. The bottom 2 corners of the big cap are cracked. I JB welded them.
At some point this bike hit something while traveling backwards or was hit from behind. I repaired all the damage, mostly pegs and accessories. I miss the guy that owned it and wish I had asked more questions about this beast while he was living. I never dreamed I'd end up being the caretaker of it.
The bike was named the Big 4 Express after his big 4 bike shop.

This bike fell together at first but since I changed a couple things, not so much, I may have angered the spirits. L0L!

SBR-CB400F · « **Reply #126 on:** August 10, 2016, 09:06:46 PM »

I love the look of an ARD hanging off the side of a motor, I can't wait to put mine on a motor.
The 836 bike looks great with the drag bike parts

Don R · « **Reply #127 on:** August 10, 2016, 10:53:55 PM »

Thanks Adam. My Daughters dragster has metal in the oil filter so it appears I have work to do. Again.

SBR-CB400F · « **Reply #128 on:** August 10, 2016, 11:53:59 PM »

Hmm it appears so, not good.

Don R · « **Reply #129 on:** August 14, 2016, 09:12:45 PM »

I haven't found the source of the metal despite taking it all apart. Anyway I got the car together and didn't get to race anyway.

I've got the big motor ready to try a start up on the stand. I want to test ride the drag parts on the 836 bike first.

Don R · « **Reply #130 on:** August 25, 2016, 09:17:44 PM »

The 1124 doesn't want to fire. no time now, I bought 2 750 cb's to resell. One's a pretty 72 with a big bore kit, It had extended forks and all the usual junk bolted on. I've got the rear end stoc now except for the fat 16" tire and stole the forks from the drag bike. I ordered new fork tubes, they'll go back on the drag bike front end with the existing lowers. all of them get upgraded as I go.

Don R · « **Reply #131 on:** May 01, 2017, 05:38:13 PM »

I bought 10 750's counting the ones above, I decided this bike needs my attention now.

I have the engine apart again looking for the tight spot, the crank seems tight in the block, I took it apart and it remained tight until I loosened the main bolts. There's .001 runout that seems to be caused by the 2-3 pistons lifting the crank out of the bearings when it's pushing them down. I don't believe the crank is bent. This is nuts. It rotates easily right now. I may drop it back together dry and tighten the mains until it acts up just to see.

Terry in Australia · « **Reply #132 on:** May 02, 2017, 01:26:33 AM »

Just fill it with nice thin oil and give it the berries Don, that'll get rid of that tight spot!

Don R · « **Reply #133 on:** May 02, 2017, 02:34:28 PM »

I tried to start it Terry, it just wouldn't spin.

I spent more time with the dial indicator. No runout, I plastigauged the main bearings, .001 with .0015 in one spot. Same as I remember it. Then I oiled it up, retorqued the mains and checked rotation. It's much easier and I have no idea why except before I used assembly lube. I'll seal up the cases again and put er back together while keeping an eye on the rotating torque.

Don R · « **Reply #134 on:** May 02, 2017, 02:36:28 PM »

Quote from: Don R on December 06, 2013, 12:49:13 PM

I thought I'd show a couple pictures of the drag bike as it gets straightened up.

Sweet Jesus, it's been a long road with so many other things getting in the way. I need a set of 400 bars, these got put on a cb400F. Black drag bars look OK but not original. L0L! This tank was ruined by a PO, and not from this bike just installed for effect.

Don R · « **Reply #135 on:** May 02, 2017, 03:09:22 PM »

Well, the new rear end parts, spool, bearings and u joint caps for the race car arrived early so the drag bike is back on the back burner We have a Super Comp race a week from Saturday at Joliet Rt. 66.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #136 on:** May 02, 2017, 03:15:48 PM »

Any valves sticking or hitting pistons/each other? Cam installed correctly?

Terry in Australia · « **Reply #137 on:** May 03, 2017, 01:09:18 AM »

Quote from: Don R on May 02, 2017, 02:36:28 PM

Quote from: Don R on December 06, 2013, 12:49:13 PM
I thought I'd show a couple pictures of the drag bike as it gets straightened up.

Sweet Jesus, it's been a long road with so many other things getting in the way. I need a set of 400 bars, these got put on a cb400F. Black drag bars look OK but not original. L0L! This tank was ruined by a PO, and not from this bike just installed for effect.

Looks great Don, well done, I love that seat! Cheers, Terry.

Don R · « **Reply #138 on:** May 03, 2017, 08:25:31 AM »

Quote from: Jerry Rxman Griffin aka MuthaF'er on May 02, 2017, 03:15:48 PM

Any valves sticking or hitting pistons/each other? Cam installed correctly?

Everything is up for inspection, no stone left unturned this time. I can check leakdown easily enough. It's spinning easily enough at the moment. I'll continue to check as the mains get tightened.

Don R · « **Reply #139 on:** June 22, 2017, 07:00:44 PM »

I have a bearing thread in the high performance section, In the end, I bought yellow bearings, put them in, and now it checks OK and turns easily.
We're Super Comp racing this weekend so it will be next week before I get to seal the cases and put it back together. I think there are gaskets I need now too.

Don R · « **Reply #140 on:** June 22, 2017, 07:31:30 PM »

I re-read this thread reminded me of a few things., I wish I'd posted the rod bolt torque at the required stretch. These bolts weren't made for stretching and don't have a center dent.

dragracer · « **Reply #141 on:** June 25, 2017, 11:50:07 PM »

What rods are in this engine??

Don R · « **Reply #142 on:** June 26, 2017, 01:41:25 PM »

Aluminum, I believe MTC? At the estate's shop sale where I got it at least 2 sets of these rods were sold, I hope they were the old ones. I didn't know the drag bike was still there until after all the parts were sold and the sale was over, I'm sure I missed out on some cool parts because I was fixated on buying the sandcast that day.

Don R · « **Reply #143 on:** June 26, 2017, 08:45:57 PM »

Cases rejoined tonight, finally some progress.

Don R · « **Reply #144 on:** July 05, 2017, 08:36:15 PM »

I hoisted the frame down off the shelf and sat it on the lift.

Then spent an evening removing sissy bar and red turn signals from a K2 and putting yellow and a stock grab bar back on it. ADD in action.

Don R · « **Reply #145 on:** July 23, 2017, 09:48:05 PM »

Two frames ready to rock, I need to decide, original resto or raked and lengthened. I haven't sent the title in on either one.

Don R · « **Reply #146 on:** August 15, 2017, 09:00:54 PM »

I started reassembly to get it running before winter so I can check it out before I take it back apart for paint and polish.

https://goo.gl/photos/VV3cigqwTnpyJWXL8

Terry in Australia · « **Reply #147 on:** August 16, 2017, 03:49:51 AM »

Looks good Don, I love that rear fender! Cheers, Terry.

Don R · « **Reply #148 on:** August 16, 2017, 09:17:38 AM »

Thanks Terry, I had one that was bashed in by a wayward luggage rack so there was nothing to lose by chopping it up. I really wanted to keep the lip around the back so I drilled the spot welds and rewelded it after trimming the top. The welds are all under the seat or under the taillight. Somewhere in this thread was a build photo unless photobucket has locked us out.

Terry in Australia · « **Reply #149 on:** August 16, 2017, 02:08:35 PM »

Thanks Don, I half-arsed one by cutting a 2 inch section out of the middle and re-welding it and it doesn't look bad, I might have to get it re-chromed and install it on my next bitsa build.

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Author Topic: Drag Bike / The Big 4 Express. (Read 65870 times)