Landracing Forum
Misc Forums => LSR General Chat => Topic started by: Warp12 on September 30, 2011, 12:27:26 PM
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I just picked this bike up (a freebie):
(http://www.warp12racing.com/images/750SOHC/750four.jpg)
It runs, title says 14k miles. Of course it needs some restoration. I am not sure what to do with it. Do these bikes have much of an LSR history? Anyway, I'm going to be kicking around some project ideas. I'm not sure if I am going to keep it or not?
I'd love to hear if there is any lore with these, or from those who have raced them. I also love to see any pics, hear your suggestions, etc...
Shane
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gee, if you can't figure it out and it is taking up space I like freebie's. I had a 1970 CB750 and it was a fun street bike to ride and sounded like an Offy.
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In the summer of '75 I bought my first bike -- a chopped and stretched '74 CB750 with slash-cut straight pipes and muffler inserts about the size of 5-cent cigars. It had a hand-painted western scene on the tank - bright yellow background - and was simply cool. I had a ball with it, especially since I didn't know much about bikes and riding - and therefore didn't know just how evil the handling was. A few years later it and I met a guard rail up close and personal when I tried rounding a corner that was too fast for the two of us. The bike probably could have made the curve - if piloted by a more competent rider.
So - sure, Shane, I'd be glad to take it off your hands and see if I could get it close to what I used to have. We'll have a trailer with us at the end of October Maxton meet, so we can fetch it then, okay? Thanks.
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Give ya a thousand bucks for it..
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I have to be honest and say that I wasn't expecting the interest! I kind of like the little bike and right now I am just interested in learning something about them and then I'll decide which way I want to go with it.
That's a great story, Jon. Glad you made it through reasonably intact!
When I was growing up, my dad had a new CB500T, followed by a couple of Yamaha XS650's. I had never really heard of the 750 Four and it's significance until years later...
I am sure that some of these bikes made their way to the salt? I see that APE still has some big bore kits and such.
Shane
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See . . .
http://www.landracing.com/forum/index.php/topic,2516.0.html
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I cut my teeth on these too! I bought a 1969 - third one in Ohio - still have it! In 1970 I first went to Speed Week with some biker friends and met Burt Munro! Saw a Triumph Dallas Trident with a small belt driven blower. Could not find one so that winter I grafted a Corvair turbo on the CB 750. If not the first turbo bike one of the first. No faster or slower but (Glenn) it really did sound like an Offy going down the chute at Indy!
Found out some years later the turbo was designed for ~1 atm boost and that's about what I had! :cheers:
Drag raced it then and returned in 1975 to run at Speed Week. Missed the record but learned HP don't count if it's not attached to the track! :-o
Then 5 more years to pay off the credit cards! :-D
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Shane,
We stock Wossner big bore kits in our Huntington Beach location. :-D
836CC anyone?
John
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Oughta save that picture -- you and Bob Higbee.
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I cut my teeth on these too! I bought a 1969 - third one in Ohio - still have it! In 1970 I first went to Speed Week with some biker friends and met Burt Munro! Saw a Triumph Dallas Trident with a small belt driven blower. Could not find one so that winter I grafted a Corvair turbo on the CB 750. If not the first turbo bike one of the first. No faster or slower but (Glenn) it really did sound like an Offy going down the chute at Indy!
Found out some years later the turbo was designed for ~1 atm boost and that's about what I had! :cheers:
Drag raced it then and returned in 1975 to run at Speed Week. Missed the record but learned HP don't count if it's not attached to the track! :-o
Then 5 more years to pay off the credit cards! :-D
Very cool story! I take it that these motors hold up fairly well? What speeds were they running out there?
I was kind of thinking of building a little racing history on to this particular bike. Maybe some LSR passes, a few passes at the dragstrip, etc.. I ride newer bikes such as the Busa and ZX's, but I have a soft spot for older bikes.
I'm going to dig around and see what pics and specs I can find from the period, so if you guys have anything, please post it! :-)
Shane
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Shane,
We stock Wossner big bore kits in our Huntington Beach location. :-D
836CC anyone?
John
The 836 seems to be popular, and I'm thinking reliable? Right now I just need to go over the bike and decide what I am doing with it...but if I decide to freshen up the motor I will keep that in mind. :wink:
Shane
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I drag raced a CB750 back in the early 70-s (before you were born Shane) ... I ran mid 11's with some head work, 812cc and a Yoshimura pipe. In its day it was a rocket ship - Then came the Z1 and everything changed.
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I drag raced a CB750 back in the early 70-s (before you were born Shane) ... I ran mid 11's with some head work, 812cc and a Yoshimura pipe. In its day it was a rocket ship - Then came the Z1 and everything changed.
HA! I was born in 1969! My youthful appearance fooled you! :-D
Mid 11's is strong! I can't imagine 11.90's on this bike!
Shane
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It's home, and safely tucked away in the garage:
(http://www.warp12racing.com/images/750SOHC/750four02.jpg)
Definitely a few bumps and bruises, but it looks fairly complete. :-)
Shane
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Ok- you were 3 years old ... My brother Tom still has the 1974 CB750K that he bought new back when you were 5. I remember that I had CR-31 Keihins carburetors and the bike was 1100 cc at some point ...
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Ok- you were 3 years old ... My brother Tom still has the 1974 CB750K that he bought new back when you were 5. I remember that I had CR-31 Keihins carburetors and the bike was 1100 cc at some point ...
Thanks Joe, I feel like a kid again. :-D
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If you have a few days...........do some reading on www.sohc4.net............Take a look at the competition page for the guy from the UK that went 200+mph.........
then look at APE and CYCLE-X for build kits...............
The $1000 offer may be a little low........depending on title, running, and solid pipes. I had a '69 in '69 and still have a '73 from new.
Your '75 should do about 105 mph on the salt in stock form..............and 120 with a few mods.
In 2009 4 of us met as spectators at the BUB trials riding CB750s........all with stock pipes.
If you look through the various classes, you would have to get the bike up to the 150mph level to compete as a 750. I think its do-able but will take a few bucks.
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I owned a couple of 750-4 bikes back in the late 1970's. Yep, I am middle aged. LOL Loved the 750's sound.
Bought a new 1979 Yamaha XS-1100 to replace the 750 Honda. Yamaha was faster.
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In 1979 I worked on a turbo Offy powered Indy car that we put in the field for the '79 Indy 500. Across the street there was a guy with a 750-4 with an aftermarket pipe. The sound from the two of them was almost identical! :-D :-D :-D
Pete
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Love the color Shane..$1350.00 :cheers:
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I owned a couple of 750-4 bikes back in the late 1970's. Yep, I am middle aged. LOL Loved the 750's sound.
Bought a new 1979 Yamaha XS-1100 to replace the 750 Honda. Yamaha was faster.
I've ridden an XS11 or two, but never a CB750.
I am hoping to take it for a spin over the weekend. The tires are new, but the front fork seals are leaking very badly. The battery is weak and I am probably just going to replace it. I need to get it in the sunlight and take a good look around.
Shane
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In 1979 I worked on a turbo Offy powered Indy car that we put in the field for the '79 Indy 500. Across the street there was a guy with a 750-4 with an aftermarket pipe. The sound from the two of them was almost identical! :-D :-D :-D
Pete
There are several types of 4/1 exhaust on Ebay. Around $400 new...I'm sure they are nothing fantastic, but might sound pretty good. The stock headpipes on this one don't look too great, I haven't examined the mufflers closely.
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I thought I was the only person who heard an Indy Offy every time I revved the CB750.
It was a terrific motor and bike - bulletproof in the day.
Biggest problem was the chain to case clearance at the output shaft in the first edition.
If the chain was allowed to go a little slack it would carve an opening in the tranny case.
Keep that chain adjusted, dude. :cheers:
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I thought I was the only person who heard an Indy Offy every time I revved the CB750.
It was a terrific motor and bike - bulletproof in the day.
Biggest problem was the chain to case clearance at the output shaft in the first edition.
If the chain was allowed to go a little slack it would carve an opening in the tranny case.
Keep that chain adjusted, dude. :cheers:
Wow, that's a very cool setup. How much speed did that one see, what year? Any more details?
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Yoshimura - 4 into 1 - beautiful music ...
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If you have a few days...........do some reading on www.sohc4.net............Take a look at the competition page for the guy from the UK that went 200+mph.........
then look at APE and CYCLE-X for build kits...............
The $1000 offer may be a little low........depending on title, running, and solid pipes. I had a '69 in '69 and still have a '73 from new.
Your '75 should do about 105 mph on the salt in stock form..............and 120 with a few mods.
In 2009 4 of us met as spectators at the BUB trials riding CB750s........all with stock pipes.
If you look through the various classes, you would have to get the bike up to the 150mph level to compete as a 750. I think its do-able but will take a few bucks.
SOCH.net looks to be a great resource. I am not really familiar with SCTA or BUB record keeping, but it looks like the lowest OHC 750cc motorcycle record is 167.8 mph in the Altered Fuel class, unfaired, and that is held by Scott Guthrie:
http://www.scta-bni.org/Bonneville/BNI_records.htm
Am I looking in the right place?
The streamlined records are in the 200+ mph range. I would say that there is probably no chance in hell that this bike could compete for a record on the salt. That doesn’t mean it is unworthy to race, imo. One nice thing with an old bike like this is that there are no big expectations.
Shane
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Biggest problem was the chain to case clearance at the output shaft in the first edition.
If the chain was allowed to go a little slack it would carve an opening in the tranny case.
Keep that chain adjusted, dude. :cheers:
Thanks for the tip, I am going to take some time to inspect the cases.
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Yoshimura - 4 into 1 - beautiful music ...
You guys are going to make me buy an exhaust for this thing!
The other Honda I have been secretly lusting after is a '79 CBX. But I simply can't afford one with the current market! I have heard some great exhaust sounds from them too. My '85 1000R Honda V4 also sounds pretty good at full wail.
For being a "Kawasaki Guy", I sure like some of these older Honda's. :-D
Shane
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Found a shot of the Corvair turbo! Built this on the kitchen table and the back porch. Could only work on the bike one side at a time!
Those were the days!! Young and dumb - but always dreaming and scheming! Wait - only the young part has changed! :-D
Couple CB750 shots from B'ville 1970
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Found a shot of the Corvair turbo! Built this on the kitchen table and the back porch. Could only work on the bike one side at a time!
Those were the days!! Young and dumb - but always dreaming and scheming! Wait - only the young part has changed! :-D
Couple CB750 shots from B'ville 1970
Great pics! I love the home-built engineering aspect. So, the turbo just never made boost, or ??
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That small case to chain clearance statement is correct, but i like to think of it as part of my journey to a well-oiled chain. Once upon a time the chain on my 750 broke and wadded itself into a ball and hit the case where it began to go 'round the drive sprocket. It hit just hard enough to crack the case a bit. That, in turn, made just enough of a crack to let oil ooze out and onto the chain. Never had chain lube deficiencies after that. . . I wasn't well-versed in stuff like JB Weld back then, dang it.
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That small case to chain clearance statement is correct, but i like to think of it as part of my journey to a well-oiled chain. Once upon a time the chain on my 750 broke and wadded itself into a ball and hit the case where it began to go 'round the drive sprocket. It hit just hard enough to crack the case a bit. That, in turn, made just enough of a crack to let oil ooze out and onto the chain. Never had chain lube deficiencies after that. . . I wasn't well-versed in stuff like JB Weld back then, dang it.
That's classic right there, Jon! I wonder what my case investigation will yield...any bets??
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Hmm, I guess it's not possible to embed YouTube vids here? Some great looking/sounding bikes on YouTube...
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Just post the url.
Pete
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Isn't the CB750 the bike that Keth Turk and some buddies took a road trip to Mexico on a couple of years ago? There is a story/blog on here somewhere. Maybe a magazine article too.
DW
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Turk collects 500cc 4 cylinder Hondas ... he has 4 or 5 of them ...
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One thing I remember about CB750-s is that they didnt "mile an hour" as drag bikes. You could build them light and they would ET but they didnt run big upstairs. Big reason I switched to Z-1's
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One thing I remember about CB750-s is that they didnt "mile an hour" as drag bikes. You could build them light and they would ET but they didnt run big upstairs. Big reason I switched to Z-1's
Yeah, I was looking at the bike last night and there is a lot of weight that would just drop off of it. My ZX's are way, way lighter as it stands. :-D
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Just post the url.
Pete
Here's a nice one:
http://www.youtube.com/watch?v=t0v-N7_BcbI (http://www.youtube.com/watch?v=t0v-N7_BcbI)
This one too:
http://www.youtube.com/watch?v=HIrSpMTv6KI&feature=related (http://www.youtube.com/watch?v=HIrSpMTv6KI&feature=related)
Not LSR or Drag, but still nice little bikes!
Shane
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Yoshimura - 4 into 1 - beautiful music ...
You guys are going to make me buy an exhaust for this thing!
The other Honda I have been secretly lusting after is a '79 CBX. But I simply can't afford one with the current market! I have heard some great exhaust sounds from them too. My '85 1000R Honda V4 also sounds pretty good at full wail.
For being a "Kawasaki Guy", I sure like some of these older Honda's. :-D
Shane
yes... buy an exhaust, 4 into 1 sounds so sweet. I had 4 - 1 pipes on both my 750-4 bikes. Smashed the snot out of one set on the 1974 bike. There may have been alcohol and an off road riding attempt involved. My memory is fuzzy. LOL
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I had one about 20 years ago
I purchased it for $90
The shop told me it was seized. they couldn't kick it over even with the plugs out
So I'm sitting on it in the driveway at home, waiting fro my brother to open the gate.
It starts rolling backwards , so I kick it into gear and it makes an odd kinda clunk?
So I press the starter button, and it starts straight up. Never missed a beat after that
A bike like yours which looks in good condition with the original pipes would fetch 10k here
There's a guy in Aus who builds 750 4 race bikes
G
http://www.ozebook.com/cr750_files/trex.htm
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Yours is newer and should have the case protector in place. I did a lot of the recall work on the early bikes (sand cast cases), which included the tach drive gear retaining screw falling out (had to pull the engine, pull the cam cover, and Loctite the screw), and replacing parts in the original oil pump system. We had problems with the early plug wires leaking during rainy weather, and the tank was so long that short guys couldn't get away from the back....and the tank was mounted on rubber looking for a ground....and your jeans get wet in the rain....and the sparks go through the tank to your "tenders" and then through the clutch lever (during a shift). :-o :-o
In the early drag racing days, we used to hacksaw out the 2 lower tubes (under the upper frame tube), and then sleeve the upper half of the main tube. Bike was a little more wobbly when you chopped the throttle in the traps, but you could get the head and cylinders off without pulling the engine. My father built the frame for the Robert B. Roberts drag bike (the B. stood for "Bob"). It was single top tube, hard tail, with the engine hung like a Super Hawk. He laid the frame out across a leveled table saw, trued it with plumb-bobs and carpenter levels, and welded it up with a stick. We had a Yamaha 80 front end and wheel....when you chopped the throttle at the end of your run, the bike laid down on the pipes and slid along in a shower of sparks....crowd loved it.
Bob won Motorcycle Eliminator at the 1970 NHRA Hi-Altitude Championships (Continental Divide Raceway...south of Denver). We tried to go faster with me on it (I only weighed 138 lbs after the war), but the bike bit real hard on the launch and crushed me so hard I lost the throttle and wobbled into the other lane. I never rode it again!! I'll post pics some day, when I get the photos unpacked. 750 SOHC stories never end, 'cause we all loved those things. :wink: I gave Kent Riches my last big bore kit and cam, and what was left of my mechanical injection system....just last year. Thanks for sparking the great memories.
JimL
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All of these great stories forced me to ride the bike today! The guy who gave me the bike told it me it ran, but the battery was dead so we just loaded it into the truck. I've known him for about 10 years, so I knew the bike would run with a decent battery. Well, I ended up throwing one of my $200 A123 cells in there so I could ride it! :-D
First I took some outside pics:
(http://www.warp12racing.com/images/750SOHC/750403.jpg)
(http://www.warp12racing.com/images/750SOHC/750404.jpg)
(http://www.warp12racing.com/images/750SOHC/750405.jpg)
(http://www.warp12racing.com/images/750SOHC/750406.jpg)
Then across to the gas station:
(http://www.warp12racing.com/images/750SOHC/750407.jpg)
And finally, yes, I had to launch it up and down the driveway:
(http://www.warp12racing.com/images/750SOHC/750408.jpg)
It's safe to say that it wouldn't blow your hat off in a windstorm right now. A little different feeling than the ZX's I run at the local dragstrip. :lol:
I am curious though as to how it would run with just bolt-on parts, in a good state of tune. I'm still grinning ear to ear from the test ride.... :-D
Shane
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Based on some input from other forum members, I've found quite a few nice looking exhausts.
This one on Ebay really jumps out at me:
(http://www.warp12racing.com/images/750SOHC/750409.jpg)
(http://www.warp12racing.com/images/750SOHC/750410.jpg)
Japanese made pipe based on the original Yosh. Anyway, I don't want to turn this into a build thread, but that sure is a pretty exhaust and pricey...maybe this winter. It looks like a Christmas present to me. :-D
Shane
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"We had problems with the early plug wires leaking during rainy weather, and the tank was so long that short guys couldn't get away from the back....and the tank was mounted on rubber looking for a ground....and your jeans get wet in the rain....and the sparks go through the tank to your "tenders" and then through the clutch lever (during a shift). "
Oh yeah,,I remember that problem, it'd run on 2 whilst your nuts were getting toasted .
I owned a '69 CB 750 for a while, untill it was shortened by a taxi that got in my way, I managed to leave my knuckle imprints across the hood of the taxi, while pushing the front end of the car 3 foot across the road, the front bike wheel came back and smashed the oil filter off too.
That engine ended up in a speedway outfit.
With fond memories of the CB, I bought another '74 model,,,bad idea, the de-tuning guru's had wrecked a beautiful engine.
After deciding on a yoshi yr12 cam (the yoshi cattle dog stated the other datona cam they made bent the stock conrods after 15 seconds on a dyno)
The yr12 cam, once dialled in correctly enabled the 750 to eat the "flavour of the year" kawa 900's , but the tacho needle hit the stopper before the real power started, and my ear tach figured it loved 12,000 rpm
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That pipe is a very accurate knockoff of the Yoshimura pipe that I ran 38 years ago. It was really strong when I had a small motor (812cc). When I went to the stroker motor we used a different pipe which was a bigger diameter collector ... don't remember who made it. As I wrote before, the Yoshimura pipe had a beautiful tone and the engine was very responsive. Throw the baffle out if you get it.
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Hey Shane, I had a sunburst orange 1974 that a biker built with an 836 kit and 4-1 pipe, Italian cafe seat, drop bars, a lot of fun. Paid $850 in 1992. Heavy, slow, weak frame, crappy brakes, scary at speed, a typical mid 70s bike. I would highly recommend an electronic ignition, you may tire of cleaning and adjusting points :-D
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Oh yeah, pretty sure that 750 record of Scott's is on a 2-stroke TZ750.
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Heavy, slow, weak frame, crappy brakes, scary at speed
I have already experienced the heavy and slow aspects. I suspect that the crappy brakes, twisty frame, and scary at speed features can all be tested out on a nearby backroad....in a single sitting. :-D
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Lots of fun stories and much appreciatged... I'd leave it stock Shane. Those pipes are rare and getting rarer. My first new bike was a '78 CB750F. It had a pretty radical camshaft and ate valve guides until I changed to an aftermarket cam. I put 55K miles on that bike and it ended up at 836cc. With aftermarket shocks, tapered roller bearings in the steering head and bronze swingarm bushings, it handled pretty decent and went pretty good.
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Here is a CB750 dirt tracker i built last Jan.... sold it at the vegas auction
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some more pix
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Here is a CB750 dirt tracker i built last Jan.... sold it at the vegas auction
Very cool. Were the 750's used for dirt track? I've never seen one like that. I've seen a lot of XS650's done that way, though...
At least one of the pics demands it's own thread! :-D
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Lots of fun stories and much appreciatged... I'd leave it stock Shane. Those pipes are rare and getting rarer. My first new bike was a '78 CB750F. It had a pretty radical camshaft and ate valve guides until I changed to an aftermarket cam. I put 55K miles on that bike and it ended up at 836cc. With aftermarket shocks, tapered roller bearings in the steering head and bronze swingarm bushings, it handled pretty decent and went pretty good.
I've only looked over the bike a bit, but the headpipes have some really odd dent's in them....near the head. Makes you wonder if the bike wasn't ridden through the brush a lot, lol.
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There was a pretty rusty turbocharged 750 on ebay last week, may still be there if you want another mechanical challenge
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There's a place in Italy repopping the pipes and mufflers. Right down to the part no. Readily available at around $1300 a set.
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There's a place in Italy repopping the pipes and mufflers. Right down to the part no. Readily available at around $1300 a set.
I've seen some sets on Ebay, and boy are they pricey. The dupli-yosh looks pretty good in compari$on.
Of course, a bike like this would be beautiful if fully restored to oem specs.
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There was a pretty rusty turbocharged 750 on ebay last week, may still be there if you want another mechanical challenge
Personally, I've got too many "challenges" as it is, lol! :-D
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1212; that bike is gorgeous! What was the high bid?
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Yes indeed Kent, it is beautiful.
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I was sittin out back my work shop saturday morning about 7am. there is road construction around the area where I live here in Gilbert AZ.
I then hear the distinctive sound of an early 4 cyl bike with 4 to 1 pipe. He is puttin through the work zones 25mph limit. I hear him up shift casually, then throttle up at the end of the work zone. Not a hard throttle on, just brought up the RPM in each gear and the pipe sounded great
If it was not a 750-4 Honda , it was an early Kawasaki Z bike. Had to be. LOL
You middle aged guys know that sound
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I was sittin out back my work shop saturday morning about 7am. there is road construction around the area where I live here in Gilbert AZ.
I then hear the distinctive sound of an early 4 cyl bike with 4 to 1 pipe. He is puttin through the work zones 25mph limit. I hear him up shift casually, then throttle up at the end of the work zone. Not a hard throttle on, just brought up the RPM in each gear and the pipe sounded great
If it was not a 750-4 Honda , it was an early Kawasaki Z bike. Had to be. LOL
You middle aged guys know that sound
Kerker Kackle? :?
Middle-aged guy aka snot-nosed kid? :-D