Author Topic: My Dunstall CB750 (Read 49491 times)

srook · « **on:** July 29, 2009, 05:10:21 pm »

I started this project many years ago (Summer 2000) and planned on building a CR750 Replica. The Cycle World article about M3's CR750 Dick Mann replica was the inspiration, so I went looking for a cheap CB750 to tear apart. $250 later and this beauty was mine.

Like any good CR should I starting ditching the stock bits. Fenders and gas tank were sold on this board. I offered the RC pipe and no one wanted it?? I even said you could name your own price (I would have sold it for $10 plus shipping)! Anyway whatever didn't sell and wasn't needed for the CR went into the dumpster. Stupid move. I would end up buying back many of the parts I had thrown away. Once I had removed the motor I noticed the cracks in the lower case. The motor was essentially junk and I ran out of steam at this point. Anyway CR replicas seemed to be the hot thing and I no longer wanted to build one for myself. Somewhere along the way I came across the woodgate site http://www.woodgate.org/dunstall/ and the Dunstall Honda. This thing was really cool and 70s and no one was building them.

I started collecting parts, graduated college, switched careers, had children and finally acquired enough stuff to start to build my own Dunstall CB750. I started in the winter of 2008. Frame and cycle parts went to the powder coater, chrome bits went to the chromer and aluminum to the polisher. I found an engine for sale locally and started to build.

rhino horn cut off and polished

Dunstall rearsets sorted, polished and chromed

Lesters polished, bearings fitted, brake bits sorted

Mock Up without the fairing (or motor)

Mock Up with fairing

Stuff still to do: rebuild motor, fab fairing brackets, add cables & brake lines, paint body work, add battery, gas, oil & smile.
Stay tuned for the rest of the build.
Thanks
Scott

voxonda · « **Reply #1 on:** July 29, 2009, 10:49:52 pm »

Hey scott,

Great choice of replicating the Dunstall. Will be following your progress. Like you said, have thrown away stuff I later had to find and buy! Is one of the reasons my shopp is a mess, do not want to do that anymore.

Regards, Rob

srook · « **Reply #2 on:** August 05, 2009, 05:28:46 pm »

Did a little bit of work. Made headlight/turn signal brackets and bolted up the fairing lowers.

Still trying to decide on a color. I really like the yellow but have been considering glossy black. Any thoughts?

Thanks
Scott

toycollector10 · « **Reply #3 on:** August 05, 2009, 11:01:26 pm »

Nice work. Keep those pictures and updates coming for us. Cheers.

voxonda · « **Reply #4 on:** August 05, 2009, 11:52:01 pm »

Really like the yellow!

Keep up the good work!

rob

mcpuffett · « **Reply #5 on:** August 06, 2009, 03:51:06 pm »

SteveD here in the uk had a Black Dunstall and there was a good photo of it, might be worth a search to find it and give you an idea what it would look like

, cheers Mick.

mcpuffett · « **Reply #6 on:** August 07, 2009, 01:23:25 am »

On second thoughts it was a Black Rickman that SteveD had and a silver & Black Dunstall that superbikeruk had,

cheers Mick.

Superbiker_uk · « **Reply #7 on:** August 08, 2009, 12:18:32 am »

Great thread - will be checking back to see how you are getting on. I have collected loads of Dunstall info over the years see attached fitting instructions for pipes - may be of interest. Will sort the dimensions of the parts you asked me about although may be a week or two. Good luck!

bucky katt · « **Reply #8 on:** August 08, 2009, 04:57:33 am »

Quote from: Superbiker_uk on August 08, 2009, 12:18:32 am

Great thread - will be checking back to see how you are getting on. I have collected loads of Dunstall info over the years see attached fitting instructions for pipes - may be of interest. Will sort the dimensions of the parts you asked me about although may be a week or two. Good luck!

damn, i love the look of that exhaust. i need one. badly

fishhead · « **Reply #9 on:** August 08, 2009, 05:40:46 am »

Quote from: srook on August 05, 2009, 05:28:46 pm

Still trying to decide on a color. I really like the yellow but have been considering glossy black. Any thoughts?

How about Blue with Brown side covers and a Black front fender ? That would be cool!!

(I also have Red fairing lowers for this bike-LOL)

Yellow or Red would look nice.

I just love the Dunstalls and will be watching this thread.
Looks like a great start.

srook · « **Reply #10 on:** August 08, 2009, 06:25:04 am »

Thanks everyone for the encouragement. Recently there has been a bunch of Dunstall stuff for the CB750 on ebay. There is currently a new in the box exhaust for you Bucky http://cgi.ebay.com/ebaymotors/HONDA-CB750-CB-750-DUNSTALL-EXHAUST-NEW-K1-K4_W0QQcmdZViewItemQQ_trksidZp3286Q2ec0Q2em14QQhashZitem4cea5d05d3QQitemZ330349479379QQptZMotorcyclesQ5fPartsQ5fAccessories and a couple of seats. Thanks for the exhaust fitting instructions Superbiker, they will help when its time to mount my pipes. Funny but each head pipe has a number 1 - 4 stamped on it but someone put tape on each pipe with a different number on it. This will get interesting when I have to figure out what goes where.

I appreciate the help with the dimensions as well. Currently working on degreasing the motor and getting it ready for paint. Will update with pics once its clean. Fishead I tried to buy your red fairing lowers about 2 to 3 years ago but you weren't selling so I had to get them from Bret at Glass From the Past. I really like the orginal Dunstall blue metalic but I don't think it could be replicated with paint. There are light blue and red flakes in the gelcoat that give it a purple look in some light and blue in others, very cool. This pic doesn't do it justice.

Great looking Dunstalls Superbiker and Fishead. I have admired them for a while.
Thanks
Scott

srook · « **Reply #11 on:** August 21, 2009, 11:14:39 am »

I have been busy degreasing and cleaning the engine cases for paint. I cleaned the upper case and painted with Duplicolor Engine Enamel 1650. I know everyone recomends the 1615 but I thought the 1650 was more a match to the original finish. If you look at the upper engine mount boss on the drive side behind the sprocket you can see where the shop I bought it from sawed through the case rather than remove the bolt properly. I used JB Weld and clamped it back on.

My cleaning method is laqcuer thinner on rags and brushes, then brass and aluminim brushes to remove the loose paint followed by 0000 grit steel wool. I use a magnet and canned air to get rid of all the steel wool residue then wipe down with lacquer thinner. I used quite a bit of paint on the upper case and shot it all within the 1hr time limit. I let it skin up (another hour or so) and then used the steel wool again with a light touch to give it a uniform finish. I found the Duplicolor very easy to use and work with.

The heads and barrels are coming off for a valve job and a rebore, then bead blasting. I am painting the barrels flat black and the heads will get the same Duplicolor 1650. The engine covers will go off for polishing. The engine will look like the one on the cover of the May 1974 issue of Cycle Guide.

I turned the engine on its side to clean and prep the underside for paint.

This thing was a leaker. I don't think the motor was ever out of the frame before but it looks like someone removed the engine covers for polishing at some point and did not get new gaskets. It leaked from every engine cover and the oil filter housing. The good news is that it runs great and there was no head gasket leak. I bought it from a shop after they did a complete service and the guy couldn't pay. Its funny that the shop has the authority to basically part it out. They offered me the entire bike for $100 more than the motor but I already had everything at that point.
Thanks for looking,
Scott

srook · « **Reply #12 on:** September 21, 2009, 03:06:36 pm »

I haven't done much work lately with everyone going back to school (me included). I painted the lower engine cases and wire wheeled the oil pan to remove the crud.

What color should I paint the barrels and head. I was planning flat black on the barrels and aluminum on the head but I am considering black for the heads and barrels. Any thoughts? Pics would be good.

With the cases painted and the oil pan back on, I can turn the motor right side up and start taking the top end apart. Head is going off for a valve job and barrels are getting an overbore. I haven't decided how far to go on the bore. I would like to keep it as close to stock as possible and go with a 1st overbore kit, but it would be cheaper to go 836 or CycleX 850. The valve cover, clutch cover, generater cover, gearbox cover and engine sprocket cover will be going out for polishing.

Here are some pics of another little project I have going; that is recreating the VIN plate. I bought a blank aluminum plate 1.25" x 3.75" and some rivets. I have a source for the decal but I haven't ordered it yet.

Scott

fasturd · « **Reply #13 on:** September 21, 2009, 03:23:08 pm »

This may be taking awhile, but the best things are always worth the wait.
I had to stop playing with bikes for a few years when my daughter was born but we now do all kinds of bike stuff together. In fact she just learned to ride.

Good luck on this build and keep the pics comming.
I am a sucker for vintage speed parts. My current 750 project has John Tickle rearsets that look exactally like your Dunstalls, I wonder if those guys were in cahoots?

Any chance you know where to get replacement footpeg rubbers? Mine are getting a little tore up.

Good luck,
Bill

srook · « **Reply #14 on:** September 21, 2009, 03:54:35 pm »

Funny you should ask. British Cycle Supply carries both Dunstall branded rubbers and Norton/Triumph/BSA rubbers. http://www.britcycle.com/products/532/532.htm The CB750 Dunstall rearsets used the unbranded Norton rubber for the shift lever and the unbranded Triumph passenger rubbers for the footpegs.

532-44 Footpeg Rubbers

532-54 Shift Rubber

532-1201 Dunstall Branded Rubbers

I have ordered from British Cycle Supply before and they are great. No worries about shipping across the border as they have a warehouse in New Jersey as well as Nova Scotia.
Scott

rachet · « **Reply #15 on:** September 21, 2009, 04:28:33 pm »

Mmmmmmmm.... Dunstall....

Watching with interest!

Rach-

fishhead · « **Reply #16 on:** September 22, 2009, 06:38:48 am »

Quote from: fasturd on September 21, 2009, 03:23:08 pm

My current 750 project has John Tickle rearsets that look exactally like your Dunstalls, I wonder if those guys were in cahoots?

Based on the J. Tickle and Dunstall rear sets I have owned, The Dunstalls usually have fold up pegs on both sides and the Tickle rear seat have fold up pegs on the right side only (for kicker clearance). The JT and Dunstall pegs intechange to each other, but I think the JT shift/brake lever pivots (where they ride on the foot peg shaft ) are slightly wider than the Dunstall units are. Some Dunstall pegs have longer mounting shafts (where it mounts to the plate) as some just bolt to the plate and others go through the plate and also through the mounting clamp on the back side of the plate, and I would assume that the JT pegs are also the same way.

My 750 has Dunstall mounting plates (CB 500/550) and Tickle pegs and levers.

Pic shows J Tickle (top) and Dunstall (bottom) for the Kawa Z-1. The JT units are much lighter than the Dunstalls (Both are made from metal, not aluminum- pretty dang heavy,esp. the Dunstalls)

Keep up the good work and post pics!!!

srook · « **Reply #17 on:** October 12, 2009, 10:26:12 am »

Anyone out there know where to get the windscreen for my Dunstall fairing?

It looks like this:

I ordered one from Gusstafson's but after an 8 month wait and one wrong windscreen he finally sent another wrong windscreen. Its a shame because I know he makes the correct screen he just can't seem to send it to me.

Definately not the correct screen.

I got the top end broken down. Everything looks real good. Barrels have to go off for a rebore and the head is going out for a serdi valve job. Both are getting bead blasted and then painted flat black. I am trying to decide between a first or second overbore kit from Yamiya or the 850 kit from CycleX. Everything else in the motor will be stock. The Yamiya kit is still about $100 more than the 850 kit.

Yamiya Kit http://www.yamiya750e.com/index.php?main_page=product_info&cPath=21_54&products_id=810

CycleX Kit http://www.cyclexchange.net/Engine%20Parts%20Page.htm

Scott

andy750 · « **Reply #18 on:** October 12, 2009, 10:35:13 am »

Go for the Big Jay kit - known quality...

http://forums.sohc4.net/index.php?topic=59909.0;topicseen

looking good!
cheers
Andy

fasturd · « **Reply #19 on:** October 12, 2009, 08:29:23 pm »

Quote from: bucky katt on August 08, 2009, 04:57:33 am

Quote from: Superbiker_uk on August 08, 2009, 12:18:32 am
Great thread - will be checking back to see how you are getting on. I have collected loads of Dunstall info over the years see attached fitting instructions for pipes - may be of interest. Will sort the dimensions of the parts you asked me about although may be a week or two. Good luck!

damn, i love the look of that exhaust. i need one. badly

That exhaust has been on Ebay a few times this year. There is a guy here in the states that had some NOS sets.

fasturd · « **Reply #20 on:** October 12, 2009, 08:34:12 pm »

Quote from: fishhead on September 22, 2009, 06:38:48 am

Quote from: fasturd on September 21, 2009, 03:23:08 pm
My current 750 project has John Tickle rearsets that look exactally like your Dunstalls, I wonder if those guys were in cahoots?

Based on the J. Tickle and Dunstall rear sets I have owned, The Dunstalls usually have fold up pegs on both sides and the Tickle rear seat have fold up pegs on the right side only (for kicker clearance). The JT and Dunstall pegs intechange to each other, but I think the JT shift/brake lever pivots (where they ride on the foot peg shaft ) are slightly wider than the Dunstall units are. Some Dunstall pegs have longer mounting shafts (where it mounts to the plate) as some just bolt to the plate and others go through the plate and also through the mounting clamp on the back side of the plate, and I would assume that the JT pegs are also the same way.

My 750 has Dunstall mounting plates (CB 500/550) and Tickle pegs and levers.

Pic shows J Tickle (top) and Dunstall (bottom) for the Kawa Z-1. The JT units are much lighter than the Dunstalls (Both are made from metal, not aluminum- pretty dang heavy,esp. the Dunstalls)

Keep up the good work and post pics!!!

Yout JTs look quite a bit different than mine. Mine are nearly identical tothe Dunstalls on this build only they are stamped John Tickle.
But your info is very helpfull as is The info about the replacement foot peg pads and shifter rubber...

fasturd · « **Reply #21 on:** October 12, 2009, 08:36:48 pm »

Quote from: srook on September 21, 2009, 03:54:35 pm

Funny you should ask. British Cycle Supply carries both Dunstall branded rubbers and Norton/Triumph/BSA rubbers. http://www.britcycle.com/products/532/532.htm The CB750 Dunstall rearsets used the unbranded Norton rubber for the shift lever and the unbranded Triumph passenger rubbers for the footpegs.

532-44 Footpeg Rubbers

532-54 Shift Rubber

532-1201 Dunstall Branded Rubbers

I have ordered from British Cycle Supply before and they are great. No worries about shipping across the border as they have a warehouse in New Jersey as well as Nova Scotia.
Scott

That is usefull info ,
Thanks a bunch!

bikerbart · « **Reply #22 on:** October 13, 2009, 11:59:06 am »

Try heating the screen with a heat gun and press creases into the appropriate angles to make it fit,looks like it wont take much.

srook · « **Reply #23 on:** October 13, 2009, 01:42:58 pm »

The screen from Gusstafsons is completely different than the original. It is much shorter and the contour is wrong. I won't be using it. What makes me so upset about the whole thing is that he makes the correct screen. There is a picture of a Dunstall CB750 on his site with the correct screen and Fishead looks to have the correct one from him as well. It took many phone calls, emails and complaints filed with the Florida BBB and the department of consumer affairs to get another wrong screen 8 months after I paid for it. I even sent him pictures of what the thing looks like. I have been in contact with a company that makes custom windshields but they want the original to use as a template. I don't have one. Anyone got a cracked or broken original I could use as a template?
Scott

fishhead · « **Reply #24 on:** October 14, 2009, 03:25:53 pm »

My screen is a Gusstafsons and it needed to be heated up and "contoured" to fit the front of the fairing and then the sides of the screen were cut down to the recess in the fairing.

The company that you are in contact with should be able to make a screen with your "incorrect" screen and your correct Dunstall fairing.

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Author Topic: My Dunstall CB750 (Read 49491 times)

srook

srook

Superbiker_uk

srook

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