Author Topic: Vintage sidecar rebuild - new video  (Read 152079 times)

0 Members and 4 Guests are viewing this topic.

Offline Sam Green Racing

  • Moderator
  • Really Old Timer ...
  • *****
  • Posts: 16,068
  • I REALLY? hate black rims.
Re: Vintage sidecar rebuild
« Reply #250 on: August 19, 2012, 10:48:44 PM »
Well done Brian, 3 seconds off the pace with what sounds like a far from perfect bike can't be bad and you did miss out on a practice session, not bad at all mate.

Sam. ;)
C95 sprint bike.
CB95 hybrid race bike
CB95 race bike
CB92
RS 175. sprint/land speed bike
JMR Racing CB750A street ET drag bike

Offline Tintop

  • Old Timer
  • ******
  • Posts: 3,965
Re: Vintage sidecar rebuild
« Reply #251 on: August 20, 2012, 04:26:36 AM »
Thank Sam.  I'm very happy with how the bike performed.  Goal was to get under 2 minutes, and we only missed by a second. :)

The metallic noise turned out to be the oil catch pan touching down.  Fixed that, then did a '3000 mile tuneup', and complete check over.  The not pulling over 5K was fouled plugs.  Seems the Weber didn't like trolling around at part thottle.  We do a 'Try the Track', were people pay $20 (goes to charity), and get 3 laps of the track on a sidecar.  The jetting change Saturday evening helped top end, but created a low end bog.  It bit on the exit of 5, and hurt the run up the straight.  I had only been dropping it down from 4th to 3rd before.  2nd would have worked now, but really buzzed it on the entry to 5. 
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 Syscrush

  • Expert
  • ****
  • Posts: 1,419
  • Sold. :(
Re: Vintage sidecar rebuild
« Reply #252 on: August 20, 2012, 08:05:51 AM »
The Sunday final was our best effort so far.  Started 8th, finished 5th.
That's a very good result.  BE PROUD!
Life is precious: wear your f'n helmet!
There's nothing more expensive than a free bike...
FWIW, I'm not a shill for Race Tech - I've just got a thing for good suspension and the RTCE's are the most cost-effective mod for these old damping rod front ends.

Offline Old Scrambler

  • My CB750K3 has been in 39 States & 5 Provinces
  • Old Timer
  • ******
  • Posts: 3,810
Re: Vintage sidecar rebuild
« Reply #253 on: August 20, 2012, 09:17:54 AM »
VERY happy for you and the ride for Lefty-GZ 8) 8)  Those 650 clutches work well enough for ordinary riding.......but needed attention after I sold a bike to a 300-lb. rider ;D

SAM......I've seen wider tracks on a golf-course ;) ;) ;)
Dennis in Wisconsin
'64 Triumph Cub & '74 Honda CB750 Bonneville Salt Flats AMA Record Holder (6)
CB750 Classic Bonneville Racer thread - http://forums.sohc4.net/index.php/topic,135473.0.html
'63 CL72 Project(s)
'66 CL77 Red
'67 Triumph T100C
'73 750K3 Owned since New
'77 750F2 Cafe Project
2020 ROYAL ENFIELD Himalayan

Offline Really?

  • I've come to the conclusion that I AM a
  • Really Old Timer ...
  • *******
  • Posts: 5,276
Re: Vintage sidecar rebuild
« Reply #254 on: August 20, 2012, 09:22:24 AM »
Hey Tintop, that rig is


SICK!!!!!!!!!
I don't have a motorcycle, sold it ('85 Yamaha Venture Royale).  Haven't had a CB750 for over 40 years.

The Wife's Bike - 750K5
The Kid's Bike - 750K3

Offline Really?

  • I've come to the conclusion that I AM a
  • Really Old Timer ...
  • *******
  • Posts: 5,276
Re: Vintage sidecar rebuild
« Reply #255 on: August 20, 2012, 09:23:36 AM »
If that rig were to end up in BOTM, what bike could even go up against it??
I don't have a motorcycle, sold it ('85 Yamaha Venture Royale).  Haven't had a CB750 for over 40 years.

The Wife's Bike - 750K5
The Kid's Bike - 750K3

Offline scottly

  • Global Moderator
  • Really Old Timer ...
  • *****
  • Posts: 16,283
  • Humboldt, AZ
Re: Vintage sidecar rebuild
« Reply #256 on: August 20, 2012, 09:33:56 AM »
What were the jetting changes?
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 Tintop

  • Old Timer
  • ******
  • Posts: 3,965
Re: Vintage sidecar rebuild
« Reply #257 on: August 20, 2012, 09:45:39 AM »
What were the jetting changes?

I tried a 130 main with 175 air, and F16 - too lean.  Went back to the 140 main, 185 air, and F11.  Top end is very good now, but when the accel pump comes in a low rev it is too rich.  Takes a bit to clear.  This was only happening coming out of the slowest corner.  Being down one more gear would have kept the revs in the right place, and avoided the issue.  The change to the F11 did help overall, and I now have a clean idle.
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 scottly

  • Global Moderator
  • Really Old Timer ...
  • *****
  • Posts: 16,283
  • Humboldt, AZ
Re: Vintage sidecar rebuild
« Reply #258 on: August 20, 2012, 09:52:23 AM »
What size idle jets?
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 Tintop

  • Old Timer
  • ******
  • Posts: 3,965
Re: Vintage sidecar rebuild
« Reply #259 on: August 20, 2012, 02:12:53 PM »
What size idle jets?

45F9's scotty.  Thinking maybe going to 40F9's, or 45F8.  Either way I have to P/U some parts.

'edit' - it was idling @ 1800 OK (would like to get it down to about -1500), and idle screws are @ +/-3/4.  Sync is still off slightly as there is a pop when cold (left cylinder?).  Clears up mostly when it is fully warmed up.  The pipes are not helping, and will need to be replaced for next season.  Primaries are about 2" too short, and not quite equal length, as is. :( ::)
« Last Edit: August 20, 2012, 02:25:27 PM by Tintop »
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 Sam Green Racing

  • Moderator
  • Really Old Timer ...
  • *****
  • Posts: 16,068
  • I REALLY? hate black rims.
Re: Vintage sidecar rebuild
« Reply #260 on: August 20, 2012, 03:07:45 PM »
If that rig were to end up in BOTM, what bike could even go up against it??

Put me down for nominating Brians bike for next month. ;D ;D ;D ;D ;D ;D ;D
C95 sprint bike.
CB95 hybrid race bike
CB95 race bike
CB92
RS 175. sprint/land speed bike
JMR Racing CB750A street ET drag bike

Offline brooze72

  • Talk to my friends here at SOHC4 if you need an
  • Expert
  • ****
  • Posts: 1,308
Re: Vintage sidecar rebuild
« Reply #261 on: August 20, 2012, 05:05:49 PM »
Sure would be a "first" having a Yammie powered rig win the BOTM on SOHC4.net :o :o ;D
2011, 2012 & 2013 Godzilla Relay Rally Rider
"Hold on loosely...don't let go
 If you cling too tightly...you're gonna lose control"
1972 CB500K1 - restored rider
1981 CB650C - new project

Offline Really?

  • I've come to the conclusion that I AM a
  • Really Old Timer ...
  • *******
  • Posts: 5,276
Vintage sidecar rebuild
« Reply #262 on: August 20, 2012, 05:20:55 PM »
I swore it was one of ours. Still sick though.
I don't have a motorcycle, sold it ('85 Yamaha Venture Royale).  Haven't had a CB750 for over 40 years.

The Wife's Bike - 750K5
The Kid's Bike - 750K3

Offline Tintop

  • Old Timer
  • ******
  • Posts: 3,965
Re: Vintage sidecar rebuild
« Reply #263 on: August 20, 2012, 05:31:07 PM »
Sure would be a "first" having a Yammie powered rig win the BOTM on SOHC4.net :o :o ;D

I swore it was one of ours. Still sick though.

Would be.... if Honda made a 'pre 73' twin that you could stretch to 750. ;) ;D ;D ;D ;D

The P3 Fiddeman will get a 915+ SOHC though.
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 brooze72

  • Talk to my friends here at SOHC4 if you need an
  • Expert
  • ****
  • Posts: 1,308
Re: Vintage sidecar rebuild
« Reply #264 on: August 20, 2012, 06:59:28 PM »
Did you just give us a sneek preview of next years project ? ;) ;) ;D ;D
2011, 2012 & 2013 Godzilla Relay Rally Rider
"Hold on loosely...don't let go
 If you cling too tightly...you're gonna lose control"
1972 CB500K1 - restored rider
1981 CB650C - new project

Offline scottly

  • Global Moderator
  • Really Old Timer ...
  • *****
  • Posts: 16,283
  • Humboldt, AZ
Re: Vintage sidecar rebuild
« Reply #265 on: August 20, 2012, 07:28:35 PM »

45F9's scotty.  Thinking maybe going to 40F9's, or 45F8.  Either way I have to P/U some parts.

'edit' - it was idling @ 1800 OK (would like to get it down to about -1500), and idle screws are @ +/-3/4.  Sync is still off slightly as there is a pop when cold (left cylinder?).  Clears up mostly when it is fully warmed up.  The pipes are not helping, and will need to be replaced for next season.  Primaries are about 2" too short, and not quite equal length, as is. :( ::)
I'd stick with the 45F9s for now, maybe open the screws to 1 turn to bring the speed down?
Sounds like in any case you have too much pump. What size pump jets are you running, and what size discharge aka accelerator pump back bleed jet? The discharge jet is about the only jet I would find drilling to be acceptable on a Weber. ;)
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 Syscrush

  • Expert
  • ****
  • Posts: 1,419
  • Sold. :(
Re: Vintage sidecar rebuild
« Reply #266 on: August 21, 2012, 05:50:36 AM »
Primaries are about 2" too short, and not quite equal length, as is. :( ::)
Don't stress about them being unequal length - brag about how they're tuned for a broader spread of torque, yielding better driveability! ;)
Life is precious: wear your f'n helmet!
There's nothing more expensive than a free bike...
FWIW, I'm not a shill for Race Tech - I've just got a thing for good suspension and the RTCE's are the most cost-effective mod for these old damping rod front ends.

Offline Sam Green Racing

  • Moderator
  • Really Old Timer ...
  • *****
  • Posts: 16,068
  • I REALLY? hate black rims.
Re: Vintage sidecar rebuild
« Reply #267 on: August 21, 2012, 08:40:18 AM »
Sure would be a "first" having a Yammie powered rig win the BOTM on SOHC4.net :o :o ;D

That's why it had these.. ;D ;D ;D ;D ;D ;D ;D

Someone REALLY? messed up ::) ::) ::) ::) ::)

Sam. ;)
« Last Edit: August 21, 2012, 08:42:17 AM by SamCR750A »
C95 sprint bike.
CB95 hybrid race bike
CB95 race bike
CB92
RS 175. sprint/land speed bike
JMR Racing CB750A street ET drag bike

Offline Really?

  • I've come to the conclusion that I AM a
  • Really Old Timer ...
  • *******
  • Posts: 5,276
Re: Vintage sidecar rebuild
« Reply #268 on: August 21, 2012, 08:51:07 AM »
I Really messed up aye?  My bad. 
I don't have a motorcycle, sold it ('85 Yamaha Venture Royale).  Haven't had a CB750 for over 40 years.

The Wife's Bike - 750K5
The Kid's Bike - 750K3

Offline Tintop

  • Old Timer
  • ******
  • Posts: 3,965
Re: Vintage sidecar rebuild
« Reply #269 on: August 21, 2012, 02:33:23 PM »
scotty - Agreed the 45F9's are probably OK.  Just need to get the idle circuit setup finalizied.  The pump jet is a 50, but don't have my setup sheet handy re the exhaust (50?? maybe).  I haven't even started playing with the pump stroke & spring rate, so there's still room for improvement there.  I'm more inclined to think that it's rev related (low rev = low air speed = poor atomization).  The only two corners were it was 'thick', or bogged I could / should have been down another gear.  Note that this only became an issue when I changed from the F16's to the F11's.  The other change was the needle from a 175 to a 200, but that shouldn't have any effect on this, except to keep the wells full(er) @ WOT.

Booze72 - The 13" isn't likely to be done for at least another year.  I'll post some pics later, but it's a true basket case.  That said the 16" is huge fun, and potentially a faster rig @ everywhere we race, but Mosport.
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 scottly

  • Global Moderator
  • Really Old Timer ...
  • *****
  • Posts: 16,283
  • Humboldt, AZ
Re: Vintage sidecar rebuild
« Reply #270 on: August 21, 2012, 02:56:40 PM »
50 pump jets are a bit on the large side, IMHO. I'm running 35s, with 55 discharge. If you look at the OEM jet settings in the Haynes book, you'll see that most dcoe 40s used 35 pump jets, with discharge jets from 35 to 100.
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 Tintop

  • Old Timer
  • ******
  • Posts: 3,965
Re: Vintage sidecar rebuild
« Reply #271 on: August 21, 2012, 03:16:06 PM »
The 50's are what were in the carb when I got it.  I'll see about getting something smaller to test.  The current bleeds should be OK for now, as their within the range.  I'll have to order pump jets, so I'll have them send some other bleeds as well.

I haven't found a single reference for an XS with a Weber, for street or racing (650 or 750cc's).  Figure when I get it sorted I should eBay a kit. ;) ;D ;D ;D ;D
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 Sam Green Racing

  • Moderator
  • Really Old Timer ...
  • *****
  • Posts: 16,068
  • I REALLY? hate black rims.
Re: Vintage sidecar rebuild
« Reply #272 on: August 21, 2012, 03:52:55 PM »
I Really messed up aye?  My bad.

 ;D ;D ;D ;D ;D That's why we love you, you're a total MESS.  ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D
C95 sprint bike.
CB95 hybrid race bike
CB95 race bike
CB92
RS 175. sprint/land speed bike
JMR Racing CB750A street ET drag bike

Offline scottly

  • Global Moderator
  • Really Old Timer ...
  • *****
  • Posts: 16,283
  • Humboldt, AZ
Re: Vintage sidecar rebuild
« Reply #273 on: August 21, 2012, 05:33:51 PM »

I haven't found a single reference for an XS with a Weber, for street or racing (650 or 750cc's).  Figure when I get it sorted I should eBay a kit. ;) ;D ;D ;D ;D
That's not a bad idea at all, given the popularity of the XS. (Do I get a cut of the proceeds? ;))
I would go to the 35 pump jets; they will give a much stronger stream than the 50s for the same volume of fuel. You might be surprised just how much fuel can be forced through the small squirters  if need be. I had 2 DCOE 40s on a 6.7L motor once. ;)
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 Tintop

  • Old Timer
  • ******
  • Posts: 3,965
Re: Vintage sidecar rebuild
« Reply #274 on: August 21, 2012, 07:21:24 PM »
That's not a bad idea at all, given the popularity of the XS. (Do I get a cut of the proceeds? ;))
I would go to the 35 pump jets; they will give a much stronger stream than the 50s for the same volume of fuel. You might be surprised just how much fuel can be forced through the small squirters  if need be. I had 2 DCOE 40s on a 6.7L motor once. ;)

I'll take a look at what else I may need/want.  It will cost more to ship x2 jets than they cost.   
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