Author Topic: Rickman CR750 with RC Engineering Cobra motor 1975  (Read 5094 times)

0 Members and 1 Guest are viewing this topic.

Offline colined2

  • Full Member
  • *
  • Posts: 31
Rickman CR750 with RC Engineering Cobra motor 1975
« on: June 03, 2015, 07:34:34 AM »
Hello again
2nd post but having trouble sending photo's as attachments in jpg format.
Sending one attachment now,if it works I'll try again tomorrow as its 12.30AM here.
Regards
Colin Edwards

Offline hotdog

  • Hot Shot
  • ***
  • Posts: 345
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #1 on: June 03, 2015, 08:34:12 AM »
Very tasty  8)
Instagram - LUMPY CAM MOTORCYCLES
FB - LUMPY CAM Motorcycles


Offline hondaron

  • Full Member
  • *
  • Posts: 68
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #3 on: June 03, 2015, 10:14:10 AM »
Better get busy Colin, with more info and photos.

See you never can tell who's watching

Ronnie :) :)

Offline colined2

  • Full Member
  • *
  • Posts: 31
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #4 on: June 03, 2015, 10:28:46 PM »
I'm back again this time at a more respectable time,2.50PM.
I have been a watcher of this forum for about 3 years and lately I have noticed a few articles on Rickman CR750's,so I thought maybe someone would be interested in my times with one and also a RC Engineering Cobra motor I built and installed way back in 1974.
I'm in my mid 60's now and it is a bit over 41 years ago when the idea of a creating something different first entered my head.
So I'll give it a go.
I had my first bike in 1968.a Suzuki T20 I think they were called,quickly followed by 2 Kawasaki A7 350's,my favourite 2 strokes.In 1971 I purchased a CB750K1.I kept it standard for 2 years until the exhaust pipes rusted out.Back in those days 4 into 1 exhausts were not available readily here in Melbourne so with a leaky exhaust I headed off very early one morning to Sydney to get one of the new 4 into 1's being sold by Bob Levy Motorcycles.It was a heavy guage system without any baffling.The way to keep it quiet was to drop a standard CB750 down the exhaust and secure with a self tapper.It was loud but I was one of the first in Melbourne with a 4 into 1.
Early 1974 I had the idea to build a chopper.
I sent off a letter to a chopper crowd somewhere in the USA and purchased a sissy bar,seat and rear guard.Thankfully the Lord was looking over my shoulder and I then realized this was not the road to travel down.
End of Part One.

Offline colined2

  • Full Member
  • *
  • Posts: 31
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #5 on: June 03, 2015, 11:44:11 PM »
Part 2
Back again.
After the chopper fiasco I noticed a story in the local motorcycle magazine "The Green Horror" about a new rolling chassis that was on sale in the UK.I sent another letter off to the Rickman Company and they told me that an agent had been appointed in Australia and I was to contact them.The Australian agent was Alron Industries in Perth Western Australia over 2000 miles away.Anyway after negotiating with them and paying the $1500.00 AU they wanted I had to wait 8 months for it to turn up.This 8 months gave me time to build up a RC Engineering Cobra motor,bearing in mind that these were early days with RC Eng. and the special RC cylinder was not available at this time.There were a few phone calls late at night to RC Eng. to make sure everything I got was what went into the Cobra motor and the person I dealt with was Terry Vance then a young man learning the ropes.
Everything came together mid 1974 and I arranged a Saturday for some mates and I to fit the motor into the frame.No dramas here,the only  thing that slowed us down on the day was getting a Honda CB450 throttle cable (one cable from twist grip to two cables going to the Webbers),I can't remember how but we got one on that day.
It started after about 6 kicks and I was surprised that the bike was rideable.The next step was to tune the carbies which I had no idea about so I rode the bike to a man who raced Ford Escorts (Graham "Tubby' Ritter) and he was able to have it running just right.
End of part 2
I have to go out for dinner at my youngest son's place tonight so I'll be back tomorrow for some more on the Rickman/Cobra saga.
Regards
Colin

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,279
  • ROCK & ROLL
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #6 on: June 04, 2015, 12:42:22 AM »
Great story so far Colin... ;)
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline Bill/BentON Racing

  • Really Old Timer ...
  • *******
  • Posts: 6,725
  • Ex Honda Service Manager, Cert. Honda Tech - Racer
    • BentON Racing
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #7 on: June 04, 2015, 01:55:25 AM »
+1. K. Bill
BentON Racing Website
OEM Parts | Service | Custom Builds
BentON Racing Facebook
Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
______________________________________
See our latest build 'Captain Marvel' CLICK HERE

Offline andy750

  • Really Old Timer ...
  • *******
  • Posts: 7,938
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #8 on: June 04, 2015, 03:20:27 AM »
Great story indeed and love the history of the bike! Keep it coming!
Current bikes
1. CB750K4: Long distance bike, 17 countries and counting...2001 - Trans-USA-Mexico, 2003 - European Tour, 2004 - SOHC Easy Rider Trip , 2008 - Adirondack Tour 2-up , 2013 - Tail of the Dragon Tour , 2017: 836 kit install and bottom end rebuild. And rebirth: http://forums.sohc4.net/index.php/topic,173213.msg2029836.html#msg2029836
2. CB750/810cc K2  - road racer with JMR worked head 71 hp
3. Yamaha Tenere T700 2022

Where did you go on your bike today? - http://forums.sohc4.net/index.php?topic=45183.2350

Offline gschuld

  • Master
  • *****
  • Posts: 2,346
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #9 on: June 04, 2015, 03:58:31 AM »
Awesome.  Please continue... 8)

Offline jaguar

  • Old Timer
  • ******
  • Posts: 2,763
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #10 on: June 04, 2015, 05:18:13 AM »
Lets see some more pictures!

Offline colined2

  • Full Member
  • *
  • Posts: 31
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #11 on: June 04, 2015, 06:48:33 AM »
Back again.Had dinner tonight with the 3 sons and their wives and partners,good time and my eldest and his wife are expecting a child in the next 3 weeks so even at 66 years of age I'm still not a grandparent,but all will change by the end of the month.
Next part of the story.
After Webber tuning and a run in period I was ready to give it a handfull.
Dramas.It kept jumping out of gear,2nd,3rd,4th and 5th.Back to the work bench and remove the motor to see if anything wrong in the gearbox.I couldn't see any problems so just to be sure I had the dogs on the gears back cut.Put it all back together and still the same problem.I was a bit bushed and as a last resort I went to the local Honda importer (Mayfair Motors in Melbourne) to see if they could help.They had no idea but they did say they would get in touch with Honda Japan to see if they could help.Honda Japan's answer was to fill in with weld the detent arm on the gear change mechanism where the spring connects and to reduce the diameter of the wheel or roller or whatever you call it on the detent by 1mm.BINGO no more gearchange problems.
After a lot of around town riding and the occasional trip to Bendigo to see my parents several of my mates and I decided to head to Bathurst NSW for the Australian GP held every Easter,this was April 1975.
Had a great ride up,enjoyed the racing and then decided on a different way to go back to Melbourne,through the mountains from Bathurst to Mittagong via the dirt roads.Started off OK but before long the rain started bucketing down and about halfway to Mittagong the bike came to a stop,no spark.Because there was no electric starter motor fitted I had gone with a system from Sebring (I think that was their name) that replaced the regulator,rectifier and battery,worked good up until then.So for the next 60 odd miles I had a mate tow me with his bike with a rope from the back of his bike to one of the fork legs on my bike,very hairy in the rain and the mud.Any way we made it without any mishaps.I left the bike at the Police station and caught the bus back to Melbourne,the following weekend I again caught the bus back to Mittagong with regulator,rectifier and battery,fitted the parts and rode home to Melbourne.These were the only problems I had with the bike.
I havn't mentioned it before but the bike on a trip would get approx.75mpg (Imperial gallons are used in Australia).
The story doesn"t have much more to go but I will finish up tomorrow.
I will attach a few more photo's but because I had a bit of trouble initially I might do them seperately.
Bye for now
Regards
Colin Edwards

Offline colined2

  • Full Member
  • *
  • Posts: 31
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #12 on: June 04, 2015, 06:53:51 AM »
Some more photo's

Offline hotdog

  • Hot Shot
  • ***
  • Posts: 345
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #13 on: June 04, 2015, 07:24:41 AM »
Curious to know where this bike is now..??? do you still own it..?
Instagram - LUMPY CAM MOTORCYCLES
FB - LUMPY CAM Motorcycles

Offline CycleRanger

  • No comment about being an
  • Really Old Timer ...
  • *******
  • Posts: 5,412
  • Central Texas Shop Manual Advocate
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #14 on: June 04, 2015, 07:50:38 AM »
Beautiful bike!
And that photo of you and the bike is terrific! :)
Do you have a copy of the Honda Shop Manual or Parts List for your bike? Get one here:
https://www.honda4fun.com/materiale/documentazione-tecnica
CB750K5        '79 XL250s     CL350K3
CB750K3        '76 XS650      '76 CJ360T

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,058
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #15 on: June 04, 2015, 08:03:10 AM »
Nice..especially with the Webers..
 Tell these guys what your brake calipers are..  They been guessing everything but Lockheed, on a bike in another thread..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Tintop

  • Old Timer
  • ******
  • Posts: 3,965
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #16 on: June 04, 2015, 01:17:07 PM »
Those are all AP / Lockheed Racing on the Rickman.
1977 CB550/4 Cafe - Speed Warrior / BOTM 03/11
1980 CB750F (project)
Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
1976 CB400 SS - stock / BOTM 04/11 (SOLD)
1973 CB750 K - basket case (SOLD)
77 CB550 Cafe build
550/750 Filter Thread
Sidecar Rebuild Thread

Offline hondaron

  • Full Member
  • *
  • Posts: 68
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #17 on: June 04, 2015, 02:15:37 PM »
And I know there are some later pics with different wheels and more trick engine parts ? :) :)

Offline gschuld

  • Master
  • *****
  • Posts: 2,346
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #18 on: June 04, 2015, 02:52:50 PM »
Colined2,

First off, thanks for sharing.  Great history and photos.  I have a question regarding your Cobra motor.  Do you recall having any overheating issues.  I imagine the Australian climate can expose the big bore motor to some challenging heat so I'm wondering if that was a concern. 

Also, please share with us how long you owned the bike and any performance numbers you may have.

George

Offline scottly

  • Global Moderator
  • Really Old Timer ...
  • *****
  • Posts: 16,262
  • Humboldt, AZ
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #19 on: June 04, 2015, 08:44:57 PM »

I havn't mentioned it before but the bike on a trip would get approx.75mpg (Imperial gallons are used in Australia).

Colin Edwards
Welcome Colin! I've logged similar mileage (converted to US gallons) with my Weber carbed 836 Seeley. ;D Looking forward to hearing more about your adventures with the Rickman.
Don't fix it if it ain't broke!
Helmets save brains. Always wear one and ride like everyone is trying to kill you....

Offline Greg H

  • When two cams is one too many .
  • Hot Shot
  • ***
  • Posts: 366
  • Still crazy after all these years .
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #20 on: June 05, 2015, 01:47:58 AM »
Hi Colin . Really enjoying your story mate , it's pure gold  ;). Looking forward to the next instalement .

Offline colined2

  • Full Member
  • *
  • Posts: 31
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #21 on: June 05, 2015, 04:47:33 AM »
Final installment.
I forgot to mention the problems I had with exhaust systems.The first fitted was a Dunstall system that exited through 2 mufflers,looked good but was the worst as I could not get the motor to rev freely.I then tried several 4 into 1 systems and finally settled on a system by Bassani.I had to modify the muffler to give it a bigger outlet and although it looked loud it wasn't too bad.
I thought the bike looked a bit plain in an all orange livery so I had a great paint job done by Brian Cavallan (still operating today as Custom Colour in West Heidelberg Melbourne Victoria) and the seat reupholstered.
Word must have got out about the bike for it was different than most modified bikes of the time and I received a phone call from a bike magazine in Sydney who said they would like to do an article on my bike.They sent a man down and I let him ride the bike and there was a 3 page story in the next edition.I kept the magazine for all these years but try and find it and scan the pages is just not happening,I hope to find it eventually.I have attached a couple of pictures from the Bendigo Advertiser 1976 who ran a story on it.
I don't know how powerful it was but I have a memory of giving the bike a run down the freeway beside AFL Park Waverly.I remember being passed by a Kawasaki Z900 at a reasonable speed so I let him get a fair way ahead and then I thought I'll see how she goes.As I rushed up on him I hit 200kph at 7500 rpm as I passed and it hit power band and took off like a rocket.I never rode like that so that scared the bejesus out of me so I backed off,at least I know that it could go like the wind.Someone asked if the motor ran hot,I don't remember it as a problem but there was a time riding through Sydney in peak hour on a summer day when I thought it seemed to be throwing out some heat but the traffic cleared and I don't think I thought of heat again.It did run a Lockhart oil cooler.
Most of the photo's I have uploaded are from slides that I scanned and they have aged very well but I only have black and white photo's of the repainted bike,such a shame as the painted bike looked spectacular (I am biassed).
I kept the bike till 1980 and under pressure from my other half the bike had to go as house and babies beckoned.I couldn't sell the bike initially as no one would pay the price I was after,I had spent a fortune and was about to lose a fortune.I eventually removed the motor and sold that to a friend who built a drag bike,added a RC Engineering cylinder and a Vertex magneto.He also swapped the motor to a modified road bike and went club racing.He was a "C' grader but he did well.The rolling chassis was sold to a Frenchman and I never saw it again.
I had lot's of good times on the bike and after the initial gearbox problems it turned out extremly reliable and trouble free.
I hope you enjoyed this story as much as I enjoyed reliving those great days of my life.
Thanks
Colin Edwards

PS
I have added a couple of photo's of a CB750K4 I restored in 2013.

Offline colined2

  • Full Member
  • *
  • Posts: 31
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #22 on: June 05, 2015, 04:52:23 AM »
I forgot the photo's

Offline colined2

  • Full Member
  • *
  • Posts: 31
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #23 on: June 05, 2015, 05:05:55 AM »
Photo's.

Offline colined2

  • Full Member
  • *
  • Posts: 31
Re: Rickman CR750 with RC Engineering Cobra motor 1975
« Reply #24 on: June 05, 2015, 05:07:52 AM »
Another one.