Honda 87 CBR600F Hurricane, project

[nvr2old]

The SOHC CB400F-CB500/550-and CB750s are so easy to work on. Valve adjusting is a breeze, way easier then the bucket and shims of slightly newer engines. You can do a complete tune and service in less then an hour.

For as ugly as that engine is on the outside, the inside actually looks really good. The oil looks like it was changed yesterday. Check out how clean the rockers are and the cam chain and valve springs..they look brand new..

 

[Buffalo Bill]

For as ugly as that engine is on the outside, the inside actually looks really good. The oil looks like it was changed yesterday. Check out how clean the rockers are and the cam chain and valve springs..they look brand new..

Yeah that pic came from a story about an AHRMA CB750 needing parts hours before the next race of the weekend. They said the same thing you did.
They stripped just of a couple rockers and springs.

 

[GregT]

The SOHC CB750 or 650 both have my attention. Like to try some vintage racing, the SOHC valve system looks really cool.

Looks cool, hard to set up right. Cam timing changes with the valve clearances as the contact point moves around the cam. You've got to set up the cam at running clearance to get it right. Then every time it's stripped, it's retime the cam again as valve stem height changes the timing again...
Then there's all the 6mm screws and studs holding the rocker pedestals and the cover onto the head. My personal record is 10 helicoils needed on an otherwise tidy customer motor.
There are a lot of easier motors around.

 

[Buffalo Bill]

Looks cool, hard to set up right. There are a lot of easier motors around.

Easier motors of that period? I'd like your opinion. For vintage racing I'm only interested in 4s of 650 & 750cc, 1975-81.
Also, the lightest bike after strip down.
Thanks!

 

[Buffalo Bill]

Fixing the cracks?

Fixing the cracks?

Working on the panels now. I used Larry's plastic epoxy method, plus some fiberglass cloth on a high stress crack.
Used a Dremel with a tiny steel burl to clean up the cracks.
Lot of deep scratches to fill.

PS: Got an email from an AHRMA member of the 2nd Generation Superbike rules committee about the eligibility of my bikes, (GSX750F Katana, and CBR600F1) :
"The 600cc are not allowed yet. They are working on a class for it on the future.I'm going to call them about the Suzuki. I see no reason it shouldn't be allowed.
I'll get back to you on that.
Thank you!"

 

[Buffalo Bill]

Started sanding, looking for body filler. Not surprised to find all this, it is a 32 yo sport bike.

left plastic, right fiberglass

 

[GregT]

Easier motors of that period? I'd like your opinion. For vintage racing I'm only interested in 4s of 650 & 750cc, 1975-81.
Also, the lightest bike after strip down.
Thanks!

kawasaki Z650. I built one for a customer a couple of years back. Z1 front end with twin discs - wire wheel too - std drum rear. Z1 carbs - same spacing, just had to rejet. Dyna S of course. Where it went off your target was the 750 top end i found and fitted.Std 750 cams on 106/108 lobe centers. Shim under bucket as standard too. I made up a 4:1 pipe using rusty Z1 headers the owner had lying around.

Finished up light and good handling with very good HP. The owner wasn't the greatest rider but every time out finished up in a group with the same two TZ350 yamahas - ridden by ex national Champs too, LOL.

With our tight tracks it needed the twin disc front. You may not - or if the rules allow, a bigger disc would help.

 

[Buffalo Bill]

rebuilding corners

rebuilding corners

Some panel corners are gone. I rebuilt them with multi layers of fiberglass cloth and Extra Working Time Epoxy, by Loctite.
Need the epoxy resin to saturate the fabric before it begins to cure.

Repaired corner-Left, normal corner-Right

 

[Buffalo Bill]

kawasaki Z650. I built one for a customer a couple of years back. Z1 front end with twin discs - wire wheel too - std drum rear. Z1 carbs - same spacing, just had to rejet. Dyna S of course. Where it went off your target was the 750 top end i found and fitted.Std 750 cams on 106/108 lobe centers. Shim under bucket as standard too. I made up a 4:1 pipe using rusty Z1 headers the owner had lying around.

Finished up light and good handling with very good HP. The owner wasn't the greatest rider but every time out finished up in a group with the same two TZ350 yamahas - ridden by ex national Champs too, LOL.

With our tight tracks it needed the twin disc front. You may not - or if the rules allow, a bigger disc would help.

Thanks! Priceless!
My target class is Vintage Superbike Middleweight (550-650cc, 1976-1981) Looks like Kawasaki is THE brand for aftermarket cams and Wiseco piston sets.

 

[GregT]

Thanks! Priceless!
My target class is Vintage Superbike Middleweight (550-650cc, 1976-1981) Looks like Kawasaki is THE brand for aftermarket cams and Wiseco piston sets.

Surprisingly for one of my builds, everything used except the Dyna was of kawasaki origin. Std 750 cams and pistons. 750 rods on the 650 crank - they use bigger rod bolts but are dimensionally the same. 650 cam sprockets on the 750 cams. 650 uses roller camchain, 750 uses Morse type.
It was actually a pretty cheap build. I picked up the 750 stuff locally from an engine that had done the crank. The owner was a Z1 nutter and had the front end and carbs in stock. He tossed the rusted Z1 headers to me and asked if they were any use. I made a collector and tailpipe using an aluminium aftermarket muffler. Two crossbraces put in the frame. One in front of the motor, one above the swingarm pivot. Seemed to be all it needed.
The OE 650 carbs even finished up cut and narrowed and used on a big CB350 four (465cc) for the same owner.

 

[Griffin]

Thanks! Priceless!
My target class is Vintage Superbike Middleweight (550-650cc, 1976-1981) Looks like Kawasaki is THE brand for aftermarket cams and Wiseco piston sets.

The 1980-1981 KZ550 would be perfect with a big bore kit in it. In stock form, they were faster than the KZ650 and 50 lbs. lighter.

 

[Buffalo Bill]

The 1980-1981 KZ550 would be perfect with a big bore kit in it. In stock form, they were faster than the KZ650 and 50 lbs. lighter.

I agree! However, that adds $1000+ to the budget.
Considered the Honda CB650 but discovered some weirdness about it. First, no support among racers, because the firing order is 1243, so they have a unique cam.
The Kawasaki and Suzuki 650s are hybrids between the 550s and 750s, so some engine parts are interchangeable.

OK, here's the real bummer: this 87 CBR600 blows any 550, 650 away. It already has 11:1 compression, 16 valves, liquid cooling, downdraft CV carbs, single rear shock, 17" wheels and full fairing, plus more little stuff and it weighs 440 topped off & street ready.
What kills me: AHRMA decided to skip middle weight bikes for their Superbike Gen 2 classes, just light weight and heavy weight. WTF!!!!

 

[Nessism]

The CB650 is a dog. It's an old design that dates back to the 1960's. The KZ650 is a much better engine and the chassis handles great too. The KZ750 like I have is basically a bore out 650 with thicker liners and (I think) bigger valves. The 750 turbo used the same basic engine too so that should tell you something about how robust the engines are.

The KZ550 engines are also good but there is some history of spun rod bearings. The bigger engine didn't have that same reputation. I had a 1981 GPz550 and loved it, but the KZ750 is WAY more fun to ride.

 

[GregT]

I agree! However, that adds $1000+ to the budget.
Considered the Honda CB650 but discovered some weirdness about it. First, no support among racers, because the firing order is 1243, so they have a unique cam.
The Kawasaki and Suzuki 650s are hybrids between the 550s and 750s, so some engine parts are interchangeable.

OK, here's the real bummer: this 87 CBR600 blows any 550, 650 away. It already has 11:1 compression, 16 valves, liquid cooling, downdraft CV carbs, single rear shock, 17" wheels and full fairing, plus more little stuff and it weighs 440 topped off & street ready.
What kills me: AHRMA decided to skip middle weight bikes for their Superbike Gen 2 classes, just light weight and heavy weight. WTF!!!!

Here they fall into pre 89 junior - which is up to 600cc. Same as our F2 of the period which was a continuation of the TTF2 which was an international class.
Last time I looked there were three or four CBR600's running locally. It's getting bigger with a couple of FZR600's turning out now too.

Yeah, the CB650 is a bigger, developed version of the CB500/4. Heavier and not a lot faster either.

The Z650 I based the build on was an early one with wire wheels and a drum rear brake. I have some reason to believe this version is probably the lightest of the 650's. As they aged, they put on quite a lot of weight. Spun crank bearings are largely a product of the type of use - and the care of the engine. The 750 bits came from an engine with a spun big end. Properly clearanced from the start, on a crank with well radiused oil galleries - not necessarily factory bearing codes either - they should last even when revved hard.

 

[Buffalo Bill]

painting this weekend?

painting this weekend?

Started the painting process. Will spray the red first, then mask off the stripes and paint all else black.
F_ckups changed the plan: had to spray more layers of red because it was a bit transparent, won't be hard enough to tape until next morning.
I painted the fairings that will be all black but darn, missed some undersides on the front cowl, so will have to go over that again tomorrow also.
Using my antique DeVilbiss air compressor.

 

[nvr2old]

Whoa..two painting projects going on at the same time. Might be a record for this site.. Patience is the key, Bill. Letting the red set overnight is the smart way to go.

 

[Buffalo Bill]

Picking up where I left off yesterday.
Will be taping for red stripes on the side panels then paint them black , plus some other all black parts.
Maybe get to the tank today. It needs some wet sanding, still a bit tacky.

 

[Buffalo Bill]

More work to do?

More work to do?

This shows today's results. The black bled under the tape, bummer…
Decided to seal it with a clear coat, then next week touch up the stripes with an air brush, re-clear coat.
It's not the mistakes, it's the fix that makes good work done.
Clear coated the tank with the same idea. There's places that will need wet sanding and buff polishing, not new to me.
Look close, you can see the black bleed under. PS: No way I could match the OEM tape stripe geometry, I did me best.

 

[nvr2old]

The parts look real nice, Bill. Are you using Fine Line or plastic tape for your stripes?

A guy I used to work for said the same as you.."a really good painter knows how to fix his mistakes" only he didn't he didn't use the word "mistakes"..

 

[Buffalo Bill]

I used green tape my paint guy sold me,'cept that was like 8 years ago. The glue has to be dried out.
I used new tape on the side cowling, that was mostly ok.
Taping stripes, you're asking for trouble. I forgot about using electrical tape.
I do a lot of experimenting when I work, looking for the best way. Sometimes it fails.
The stripes on my Suzuki Katana I did just last April came out great, that was stripe over base. This time I tried base over stripe.