Winter 18-19 project rat bike "the Rocket"

jonesn7

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Back in late August, I picked up a VERY abused '79 CB750F SuperSport for the winter project. It was in sad, sad shape. Front forks replaced with Kawasaki leading-axle forks that gave it a trail around 3", which obviously caused head-shake that had been addressed with a poor excuse for a steering damper. These forks were 36mm that had been wedged into the original 35mm tripple clamps! The bike had been left outdoors in the East Tennessee weather since at least 1999 - when it was last registered. Head bearings looked like someone had taken a cold chisel to the bearing area. All calipers frozen and of course all brake lines and master cylinders shot also. Only the rear caliper was rebuildable. Chain rusted solid. Tank had ~20 year-old gas in it (luckily pre-alcohol) and Bondo peeling of some rather serious dents - one measured .6" thick. All wheel bearings shot. At least the airbox was intact and the engine had no water in it, but the valve clearances were way off and two cam caps busted. Cam chain adjuster bolt broken. Rotor commutator heavily corroded and stator had a partial ground. Very little paint left on the bike, almost looking like it had burnt but wiring harness was intact.

So, All of this has been addressed. New bearings, ebay and rebuilt front calipers, new lines, new Chinabay MCs. GL1000 front forks and tripples with CB lights and meters adapted to fit. Harness connectors cleaned or replaced. Rotor commutator cleaned and polished, stator cleaned and baked. New battery, tires, chain, handlebar (because I hate the stock ones) and grips. Cam caps replaced with correct ones, shims changed to correct valve clearances, cam chain adjuster bolt broken piece removed with new bolt installed. Tank cleaned inside and new petcock installed along with new fuel lines and inline filter. And of course, carbs removed, disassembled, sonicated, cracked overflow tubes slodered up, reassembled and reinstalled. Carbs balanced.

Notice there is nothing listed about appearance. It is intended to be a "rat bike" so it has had nothing done that didn't improve function. I did put a mesh seat cover on it, but primarily to keep from rubbing the tape that holds the seat together off of it when riding. The youngest daughter gave it the name Rocket, so I put a period rocket on the side panels.

Yesterday was very nice here, so I took it over Norris Dam (which is spilling due to historic rainfall) on one of my favorite loop rides. She runs great! I've not ridden a 750 before - mainly GoldWings. It accelerates hard and seems to handle very well without surprises. Riding position has feet a lot higher than on the GL, but overall was very comfortable for the 50-60 miles I did, and I'm really happy with the lower bars, even for my 66 year-old body. Took the opportunity of catching some photos at the Norris overlook.

This makes three street bikes on hand, so it will soon go on Craigslist to get my investment back out and prepare for hunting next winter's project - hopefully a '79 GL1000.
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Been to the Honda hoot twice when they put it on. Once on a Honda shadow 1100 and on a gl1800, visited the damn both times. Lots of work on your rat, cool.
 
Love the Rat Bike, FYI theres at least 1 negative Nancy's on the site that has a bad view of the "Rat" Rod/Bike projects! Lol just a funny story about a guy who thinks looks dictate performance and functionality :bs::shhh:, anyway nice resurrection! Those inline 4 bangers are a hoot to hit the back roads on!
 
Love the Rat Bike, FYI theres at least 1 negative Nancy's on the site that has a bad view of the "Rat" Rod/Bike projects! Lol just a funny story about a guy who thinks looks dictate performance and functionality :bs::shhh:, anyway nice resurrection! Those inline 4 bangers are a hoot to hit the back roads on!
I'm not a fan of FAKE rat rods and rat bikes. Those that have had paint sanded through and mild acid laid on to rapidly produce rust spots, then cleared over. Fake rust kits from Hobby Lobby on the frames. The aging on this girl is honest, and I felt it would have been a disservice to pretty her up. Things on her that are new look new (mirrors, master cylinders, brake lines, grips). However, a rod should have great performance, so I spent time on the engine (stock, but tuned well), brakes (rebuilt), and front suspension (fully rebuilt GL1000 37mm forks). The rear has Koni shock, I've been told. Rebuildable, but seem to be Ok as they are. My area seems to have a lot of rat rods - both honest and fake. There are also some amazing rescued vehicles. The ones that impress me at shows have build books showing how the owner drug it out of a field and did all of the work themselves. All that I farmed out on this bike was mounting the tires.
 
Check out Rat Rod Recipe in the projects forum, I love the Rat culture, it dosn't have to be beautiful, billet, or chrome, just home made and driveable.
 
Check out Rat Rod Recipe in the projects forum, I love the Rat culture, it dosn't have to be beautiful, billet, or chrome, just home made and driveable.
From that thread, "(t)he true soul of a rat rod is a car put together with whatever you have". The GL1000 front forks were left-over from my Hunley build because they were not pretty enough for it. The front fender was on the Kawasaki forks, I just drilled different mounting holes. The CB750F meters are mounted to the GL1000 tripples with a couple rough-sawn 1"x1/4" straps that were laying around. I made new baffle inserts for the exhaust by welding 1" tubes to disks cut from the scrap Chinese steel back splash for my HF mini-lathe. 75% or more of the work required was due to PO hacks, though.
 
Rode it in to Knoxville last night for Time Warp Vintage Motorcycle Club meeting. My first time to be at their meeting (and join). Several old GoldWing friends there, and made many new friends. The CB750F ran fine! Only problem noticed was that the idle gets higher and higher as it warms up. I was barely able to get throttle increase from the choke full-out when I did the rebuild. Couldn't find a reason for it, and compared setup to photos in the SeanG document. So, I have to crank the throttle stop up a little to keep it running until really well warmed up then back it down, but seems to continue to creep up after that. I'll do another vacuum leak check soon with it both cold and again after about 20 miles of riding.

Also, mounted (just wedged in above the ignition switch) a cheap ebay digital voltmeter temporarily and connected it to the tail light fuse. Charging system seems great! Running at 14.1 volts over (I think) 3k rpm. Rode home with it turning dark, and headlight was adequate. Might need aimed just a little higher.
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Next ebay purchase may be a cheap digital tach. I'm having trouble believing the mechanical tach - seems to be reading high while the speedometer is obviously optimistic by a bunch.
 
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