Topic: My Dunstall CB750

[srook]

Did some work this week.  I got the fairing the mounted.  I had the metal shop teacher at the school I work at, make me the front fairing mount.  It needs to be finish welded but works great considering he did it from my crude drawings. It is similar to the original in shape and the way it mounts.  I tweaked it a little to get it to fit the fairing nicely.















Once the bracket is finish welded I can drill the mount holes and the body work will go out to Empire GP for paint http://www.empiregp.com  I'm going with yellow.  I still have to build the top end.  I'm going with the Cycle X 850 kit and a valve job.  Everything else will be stock.  The next update will be motor pics.
Scott

[srook]

I'm back to work on the Dunstall project.  Since I cut off the rhino horn and ditched the stock speedo and tach for the original CR750 build, I didn't have any indicator lights.  I got a later style dash panel, stripped and polished it.  The silver dash label came from Yamiya.  It bolted right up to the earlier K1 triple clamp and now I have indicator lights.





I got a gasket and seal kit from Cycle Exchange and bolted up the polished engine covers with stainless allen bolts.  I got the kickstart shaft cover from Joker Machine.  I will be running without the kickstart because it interferes with my Dunstall rearsets and it is redundant anyway.  My car doesn't have a hand crank on it either.





More to come.  Next is the bored cylinders and camchain tensioner.
Scott

[andy750]

Looking very very nice Scott!

[bgfootball67]

Can't wait to see this one finished!  I have it's cousin sitting in my garage ready for a cosmetic resto, 78 Suzuki GS1000 Dunstall kitted bike.

[srook]

The engine is coming along.  I replaced the valves with new OEM style ones made in Japan.  The originals were pitted.  The seats were recut and the guides all measured in spec.  New seals, some bead blasting, paint, and the head is ready to go.  All I have left to do is buy the piston kit and get the barrels bored.  Then the motor can go back into the frame.  Riding this summer actually looks like an option.

Valve job and painted


New Valves


Painted head with polished valve cover


Thanks for looking
Scott

[traveler]

The build looks outstanding!

~Joe

[fasturd]

Going to be super cool. Love the vintage bits!

[srook]

More motor work.  I had the cylinders bored to fit some NOS .25 oversize pistons I found on ebay.  The pistons, rings and clips cost me just a little more than the CycleX or Z1 oversize kits, but I have the piece of mind knowing that they are OEM parts.  Now I have to finish cleaning the cylinders and paint them.  I still have to get new cam chain tensioner wheels and then the motor can get bolted back together.  I also had the starter cover and the clutch cover chromed locally.  When I am done with the build I will give a list of work done, who did it, and if I would ever use them again.  I had 2 goals in mind when I started building in 2008: get all work done locally (no shipping parts around the country) and don't use anything that wouldn't have been used in say 1974.  I don't know if the kickstart shaft cover and stainless brakes lines were used in the 1970s but everything else was.  Hopefully the next pics are with the engine installed in the frame.

New chrome


More new chrome


NOS .25 oversize pistons and rings


Piston and rings


Pistons & rings installed


More pistons & rings installed


Piston domes have 25 printed on them


Thanks for looking
Scott

[srook]

State of the Project today:
All brackets for the Dunstall kit completed
Front & Rear Brakes completed
Wiring completed
Wheels completed
Rearsets completed
Suspension & Frame completed
Sprockets & Chain completed

In Progress:
Motor almost completed

Needs:
Cables
Carb rubbers
Hoses
Correct Mufflers, Emgo replicas don't fit the OEM Dunstall Exhaust
Paint

Goals:
Running and rideable this summer
Paint over the winter



Scott

[srook]

Motor is done.  I just need to set the tappets and bolt the valve cover on.  Stock motor with .25 overbore and valve job with new valves.  New cam chain tensioners.  Painted with Duplicolor 1650.  Engine covers polished.









Motor will go into the frame this weekend.
Scott

[andy750]

Beautiful work Scott and really enjoying your progress. Good luck with getting the motor back in the frame and cant wait to see this finished.

Andy

[750]

Beautiful!! Can't wait to see the finished product.

[fishhead]

Looking good!

  I have the Emgo mufflers on my Dunstall exhaust(4 into2), I just used the sleeves/adapters that came with the mufflers.
    The lowers may need to be modified a bunch to fit once you get the motor in. The set I have would need the fronts cut (for where the exhaust exits the motor) and the left hand side would need a big "hole" punched in it for the alternator to poke through. The leg clearance area may need to be cut some also (for comfort).
 

[SKTP]

Look so good...are you happy with the engine paint color? I ask because it can look different in pictures on the internet than in real life. I need to choose a color soon.

Did you buy a "stainless allen bolts" set? If so, from where?

That's a sweet look machine you have going there, really unique...

[srook]

Thanks for the support.  I am happy with the engine paint color.  It looks very similar to the OEM color.  I think the 1615 is a close match as well.  Judging from the colors of the caps the 1615 looked a little yellow, that's why I went with the 1650.  The Duplicolor was very easy to work with.  I originally wanted to paint the barrells black, but I wasn't confident I could get enough paint between the fins.

The lowers aren't attached at the bottom yet so they kind of flop around.  I was hoping I didn't have to cut them.  I wanted 2 different looks, so I am not sure if I will run the bike with the lowers on it anyway.  The motor looks so clean that i didn't want to cover it up.  How do the GFTP lowers compare to your original Dunstalls? 

As with everything Emgo, what they claim will fit over a 1.5/8" pipe, actually measured 1.9/16".  I cut slits into the muffler inlet to open it up a little bit and it still didn't work.  At that point I stopped messing with them and sold them.  A company in England makes a Dunstall Decibel Replica that will fit 1.3/4" or 1.5/8" pipes, so I am going with those.  I imagine the Emgos are all different depending on the day they were made.  Consistency isn't their strong suit, either is measuring.

Slits in Emgo Dunstall Decibel (still didn't fit)


English made Dunstall Decibel Replicas


Left side with the lowers mounted.


I have an NOS Dunstall windshield and fairing mount on the way.  Will update with pics when they arrive.
Scott

[fishhead]

I guess my Emgo's were made on the day that a supervisor was there. I checked them and they have no sleeves on them and fit fine.

 I don't know how the GFTP lowers compare with the Dunstall lowers. I've only had the Dunstalls.
   My Dunstall lowers, when mounted to the fairing (as far out as possible and lining up with the body line on the bottom of the fairing) would need to have the alt. hole put in it or it would be bowed out (very noticeably).
 The Dunstall literature that I have don't show the left side of bikes very often.
 

[theofam]

Gorgeous build, srook!

[srook]

Got the motor in on Monday.  Used the 2 person grab and lift method.  Went really well except for lining up the front drive side motor mount bolt.  It took a little grunting to get that one in.  Since Monday I have been fitting and re-assembling everything. 

Needs to run:
Oil Hoses - still not sure what to get here.  I want a nice clean look.  I think I am just going to go with 1/2" hose, non-braided
Custom Throttle and Clutch Cables - will order this week
Battery - Run out and buy
Mufflers - Still have to order from U.K. (saving pennies)











Anyone got any extra oil tank bolts?  I need 2 of them.


Thanks for looking
Scott

[srook]

Last summer a couple of Dunstall exhausts were sold on ebay with the muffler/passenger peg brackets.  I almost bought a set just for the brackets.  Did anyone here buy a set?  If so would you be able to give me the lengths of each side, thickness of the plates, and what they are made of (Aluminum or Steel)?

Chain side plate.  I am assuming angle D,E is 90 degrees.  Anyone got the lengths?


Brake side plate.  Again I am assuming angles D,A and A,B are 90 degrees.  Lengths anyone?


I also scored an OEM windscreen.  I wanted a smoked one but at this point options were limited.  It fits much better than that piece of junk I got from Gustaffson's.  Be careful if you ever deal with them.  I will tell the tale when this bike is finshed and I rate all the suppliers & shops that have helped me along the way.

Dunstall windscreen, the way it's supposed to look and fit.


Another angle


And the state of things so far.  I'm getting there.  Only waiting for custom cables from Motion Pro, 8" under stock (32" throttle pull and 45" clutch).


Thanks for looking.
Scott

[seaweb11]

Very nice job.

[srook]

Thanks.  I really like your Tracy bike.  I have been thinking of picking up a Tracy body just for a change of pace from the XL size Dunstall bodywork.  That's a project for down the road though.

If anyone is interested, here is a link to an article on the Dunstall 900, from the May 1974 issue of Cycle Guide (click the cover).  Good article with great pictures.

[img width= height=]http://i892.photobucket.com/albums/ac130/rookster/b4_1_b.jpg[/img]

Scott

[srook]

Woke up early Friday morning and got the bike running for the first time since I have owned it (10 years).  I took it for a spin around the block and it ran great.  I still need to get some mufflers for it and I need to change the clip-ons to the original style ones.  Paint will have to wait until this winter.  My goal for the rest of the summer is to get any issues cleared up and change out the clip-ons.  So far there are no leaks or smoke and the electricals are all working properly.  It really needs some shakedown miles to show any potential problems.  Tomorrow: get insurance and visit the DMV.

Video of first start and run:
[youtube=425,350]<object width="425" height="344"><param name="movie" value="

name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="

type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>[/youtube]

Scott

[srook]

I picked up some very well used Dunstall Decibel Silencers and the correct peg/muffler brackets for the Dunstall Exhaust.  The mufflers are in great shape structurally.  There are no dents or holes and the mounts are all solid and not deformed.  The big issue with them is rust.  Most of the rust is just surface rust and they did clean up quite a bit.  I am going to have them re-chromed in the fall.  There will probably still be some pits that don't polish out, but I would rather have the real Dunstall silencers than the knock-offs.  They sound great and seem to balance out the XL Dunstall bodywork.  I have a set of genuine Dunstall clip-ons coming as well.  These are the kind that mount to the top triple tree rather than the fork tubes.









Thanks for looking.
Scott

[Laids]

Hi Scott; your build is coming along nicley. I just bought a set of Dunstall pipes today. I had been looking for a while and a second visit to a local bike shop turned up the last set he had, the rest sold on E-Bay last year. I noticed on the picture you used to show the dimensions of the mounting plates that Dunstall was stamped into them. Mine are the same configuration as that but no stamp, are the plates you bought stamped?
Out of couriosity, since your first recording of start up was pretty clear, can you record with the Dunstall silencers on, it would be great to hear. Also,what is their length?

Cheers; Laids 

[srook]

Ontario Cycle Salvage?  Do you know if they have any other Dunstall Honda stuff?  I'm not too far away from them or you in WNY.  My plates were not stamped either.  It seems that Dunstall stamped some stuff and not others.  It's very erratic and this is due to the Dunstall company not really producing anything themselves but having different vendors make things to their specs.  Even the Dunstall Decibel Silencers aren't all the same.  The overall length on the Decibels is 27".  Here are the measurements if anyone wanted to have a replica made out of stainless"
The inlet diameter measures O.D. 1.3/4"
The megaphone starts at O.D. 1.3/4" and expands to O.D. 3.1/2" over a span of 25.1/4"
The reverse cone starts at O.D. 3.1/2" and tapers down to O.D. 3.1/4" over a span of 1.3/4"

Here's a visual:


I did qoute a pair of these out from Apollo Cones in stainless and it came to just under $500 for the pair.  The only issue is that the weld seams wouldn't be ground down like the originals and I would have to have them polished.  I would probably be looking at well over $600 to have new ones made in stainless and finished.

I have some video of the bike running with the Decibels but the camera is too close to the motor and you hear alot of clutch and cam noise.  I will try to upload it soon.
Thanks
Scott