New 700cc Outfit

[YamadudeXS650C]

Signal, I somehow missed this thread first time round. Very impressed with all your hard work.... It is hard to describe how much this thread has boosted my enthusiasm for motorcycles.

This thread reinvigorated my enthusiasm for road racing, too. Unfortunately, aging has caught up with me. But I'm getting a great "contact high"

 

[Signal]

Time for a quick update before Boxing Day 2020

We had a had a great trip down to the Mike Pero Southern Classic and despite being rained off after only one practice session on Friday enjoyed some good racing and socialising over the weekend.

We decided to strip the motor and check both motor and the chassis over before the boxing day races.

We had been told by a tuner and racer we respect to check the crank is still true as under racing conditions they have been known to slip relative to each other and upset the timing.

What we did find was that one of the lead balancing weights in the crank had worked loose and had been contacting # 4 conrod. Luckily, we caught this in time and further good luck it was the outside wheel. The crank wheel has been replaced with a later wheel that has holes drilled for balancing rather than led insert.

Another problem was the rear brake master cylinder actuator rod had rusted and while attempting to fix it I ruined it completely. After a quick trip to the local wrecker, I found a replacement, stripped it cleaned it up and fitted it only to find the thread pitch was M10 x 1 and the bike had a M10 x 1.25 double banjo bolt. All sorted but much exasperation.

A better mount for the bypass valve on the carb header rail was also made and two of the reed petals were also replaced.

The carbs and air filters were cleaned, and I noticed that most of the jets appeared to be partially blocked with oil, this may explain why the bike is reluctant to start after sitting for some time.

There are 5 XS’s outfits entered in the Cemetery Circuit so there will be close racing all through the field. We are hoping the RD will be at the pointy end scrapping it out with the big bore Norton’s and the fast BMW’s. However, we are realists and know how hard it is just to finish a sidecar race on that track let alone place.

Both the RD and XS are in the trailer now ready for scrutineering Christmas day.

 

[YamadudeXS650C]

Best Wishes for the upcoming race !

 

[Rasputin]

Hot sticky tyres on Boxing Day. Good luck. Hope it all goes well. Happy Xmas.
My claim to fame early 70s. I’m the passenger with the red helmet.

 

[Signal]

Push starts not done now for safety reasons, nothing like starting a race half worn out.

 

[Rasputin]

Push starts not done now for safety reasons, nothing like starting a race half worn out.

Only managed to get left behind once. But I did go out the front on a couple of occasions.

 

[Signal]

Rasputin the ultimate indignity is when you go out the front and then get run over by your own outfit.

We were at the track bright and early Boxing Day it was fine and mostly sunny, but a chilly wind prevailed all day.

The RD had the fastest time in practice and in qualifying. The trick to racing on street circuits here is to go pretty much as fast as you can as soon as you can because often the qualifying session is cut, and the organisers use your practise time.

Race 1 one outfit jumped the start (and was later penalised) but in short order The RD was out the front making easy work it. There were two big horsepower Norton’s and a quick BMW getting left behind. Sadly, on the last of 8 laps the bike was off song and slowed, they were able to salvage 2nd place but that was it for us.

Back in the pits with the clutch cover off it was soon apparent something was amiss in the gearbox. A friend was riding the XS #250 with another son and retired also on lap 7. He was worn out and suffering cramps.

By race 2 our friend had suffered enough in race 1 and offered #250 to my mate so in the second race it was a Father /son team and brother/ daughter team both on XS’s.

My mate’s son and daughter road the wheels of their now tweaked up XS and finished the day with a well-deserved second overall. When the racing video is out, I will post a link.
All in all, a good day we had a plenty of fun with no injuries and we know we are on the right path with the RD.

Today we pulled the motor to survey the carnage second gear gone, and number 4 piston has a tiny crack in the skirt. The lead weight incident no doubt has something to do with that.


New pistons ordered and the short-term fix for the gear box is replace broken parts. After the trip to the Burt in February we will make a cush drive for the rear sprocket and adapt a sport bike gearbox and clutch to the RD, something along the lines on a R6.Probably fit some VM34’s to it as well but those jobs are going to be done in the off season.

 

[YamadudeXS650C]

Looking forward to the video !

 

[Rasputin]

Rasputin the ultimate indignity is when you go out the front and then get run over by your own outfit.

We were at the track bright and early Boxing Day it was fine and mostly sunny, but a chilly wind prevailed all day.

The RD had the fastest time in practice and in qualifying. The trick to racing on street circuits here is to go pretty much as fast as you can as soon as you can because often the qualifying session is cut, and the organisers use your practise time.

Race 1 one outfit jumped the start (and was later penalised) but in short order The RD was out the front making easy work it. There were two big horsepower Norton’s and a quick BMW getting left behind. Sadly, on the last of 8 laps the bike was off song and slowed, they were able to salvage 2nd place but that was it for us.

Back in the pits with the clutch cover off it was soon apparent something was amiss in the gearbox. A friend was riding the XS #250 with another son and retired also on lap 7. He was worn out and suffering cramps.

By race 2 our friend had suffered enough in race 1 and offered #250 to my mate so in the second race it was a Father /son team and brother/ daughter team both on XS’s.

My mate’s son and daughter road the wheels of their now tweaked up XS and finished the day with a well-deserved second overall. When the racing video is out, I will post a link.
All in all, a good day we had a plenty of fun with no injuries and we know we are on the right path with the RD.

Today we pulled the motor to survey the carnage second gear gone, and number 4 piston has a tiny crack in the skirt. The lead weight incident no doubt has something to do with that.
View attachment 181418 View attachment 181419

New pistons ordered and the short-term fix for the gear box is replace broken parts. After the trip to the Burt in February we will make a cush drive for the rear sprocket and adapt a sport bike gearbox and clutch to the RD, something along the lines on a R6.Probably fit some VM34’s to it as well but those jobs are going to be done in the off season.

I believe the Cush drive on the rear wheel is one if not the most important thing to give the gearbox an easier time on a road bike, so even more important on an outfit.
Race bikes generally don’t use them but an outfit needs that element of protection.
Unless of course you have an ultra close box and a quick shifter.
IMO.
By the way, Great effort. Looking forward to the video.

 

[Signal]

Hi, been busy in the workshop getting ready for the trip down south.

During the check over and repair of the outfit we found some more lead weights were loose in the crank. As a permanent fix they were removed, and steel slugs have been pressed then welded into the crank wheels. To rebalance the wheels, we copied the position and size of the holes in the later crank wheels (made a crude drill jig) and drilled them out. Hopefully no more problems.

The rear wheel now has a cush drive sprocket this was made by drilling a new blank sprocket with oversize mounting holes and then pressing in UHMW polythene bushes with steel liners for the mounting bolts the whole lot kept in place by a stainless flange. We have been told the red urethane is the best material for the bushes but have yet to source some. We will use the polythene until we can get some urethane.

The new pistons arrived and are being prepped for use and the gearbox has been repaired.

I found the video footage of the Boxing Day racing on YouTube.

Half the field were Yamahas #’s 611, 84, 266, 207, 364 (our black bike) were XS based machines and the RD #249.

Bike # 551 has a Honda CB 900 motor in it, but it is let down by the chassis with poor brakes and skinny wire wheels. It is a repower of an old chassis.

The Classic sidecar qualifying is at 1:09, race 1 3:09 and race 2 5:35.

Another short video with some more footage of the RD.

 

[Rasputin]

The chain coupling from the gearbox to the jackshaft is both simple and effective. I would think that the inertia having to speed that up and slow it down would be immense. I suppose it could be viewed as a benefit in softening the power delivery or a disadvantage in sapping horsepower.
Well done.

 

[YamadudeXS650C]

Hi, been busy in the workshop getting ready for the trip down south.

During the check over and repair of the outfit we found some more lead weights were loose in the crank. As a permanent fix they were removed, and steel slugs have been pressed then welded into the crank wheels. To rebalance the wheels, we copied the position and size of the holes in the later crank wheels (made a crude drill jig) and drilled them out. Hopefully no more problems.

The rear wheel now has a cush drive sprocket this was made by drilling a new blank sprocket with oversize mounting holes and then pressing in UHMW polythene bushes with steel liners for the mounting bolts the whole lot kept in place by a stainless flange. We have been told the red urethane is the best material for the bushes but have yet to source some. We will use the polythene until we can get some urethane.

The new pistons arrived and are being prepped for use and the gearbox has been repaired.

I found the video footage of the Boxing Day racing on YouTube.

Half the field were Yamahas #’s 611, 84, 266, 207, 364 (our black bike) were XS based machines and the RD #249.

Bike # 551 has a Honda CB 900 motor in it, but it is let down by the chassis with poor brakes and skinny wire wheels. It is a repower of an old chassis.

The Classic sidecar qualifying is at 1:09, race 1 3:09 and race 2 5:35.

Another short video with some more footage of the RD.

Exiting races !
Thanks for sharing !

 

[halfmile]

Great video`s. A question. Do you guy`s race Flat Track and if so is it a RH turn?

 

[Signal]

Speedway in NZ is probably the closest to US flat track that I can think of. Sidecars are right turn, no brakes they are popular but we dont race it. I regard the sidecars as too dangerous.

 

[Signal]

Some slomo footage of the classics going over the railway lines at Suzuki corner. You dont have to join facebook to see video.

https://www.facebook.com/video.php?v=10225042557959818

 

[Paul Sutton]

Interesting how the slow motion makes all the suspension and flexing come to life.

 

[Signal]

It’s been a long time since I posted an update.

We did a heap of work on the bike getting it ready for the races. We also made a roller starter and fitted a gear position indicator to the bike.


As far as racing goes for us the Burt Munro this year was a washout. The hill climb was cancelled due to the appalling weather and we were pretty pleased it was called off as it was miserable.

The practice at Teratonga racetrack on Friday was good the bike was running well and had qualified well. In the first race the bike did not run right and was limping home when the bike locked up solid.

Back in the pits we soon found that the crank had snapped in between number 2 and 3 cylinders. We had no show of fixing it although we did get several offers of workshops to use. The racing here is in the off season, so the bike has been left broken on the table until we get enthusiastic again.

When the crank is rebuilt, we will use the standard TZ firing order 1,3,2,4. It easy to swap the HT
leads over once the crank is rebuilt to suit. We had good reason to use the 1,4,2,3 timing but it looks like it might be not good for longevity.

On a brighter note, I met a man who had built his own flow bench and dyno and he kindly offered to show us round his workshop. It was pretty impressive, and he also lives at Oreti beach (where Burt Munro did test runs).

He has since sent me plans for the bench and a copy of his spread sheet to use when I get mine up and running. I have wanted to build a flow bench for some time since Jack started sharing his info on D porting which is something I am very keen to have a go at.

We also picked up some XS engine parts including heads without matching rockers that will be ideal to experiment with learning to port.

In between building the flow bench we have rebuilt a stock XS motor to replace the long rod 750 motor in #250. We intend to sell #250 but want to keep the LR motor as a spare for the new XS outfit yet to be built.

 

[Signal]

A short update, although not much has been done on the 700.

In the interim we have upgraded a friends XS 650 outfit to a 750 and fixed a number of issues the bike had.

Our black bike has been repowered with a stock 650 motor and is now for sale.

My mate has bought a F2 chassis that had a 1000cc motor in it. the plan is to put it back to F2 specs with a Suzuki 600 engine.

Today he pulled the motor from the RD 700 and we now have an idea of the damage.

Lots of little things are broken, even a bolt has sheared on the ignition stator.
Here are some photos more to come.

 

[Signal]

Here is the bike almost completed. He made a great job.

 

[Signal]

Brief Report on Boxing Day.

In qualifying the Team got a bit close to the curb on one corner and broke the end off the chamber at the weld. Luckily the stinger goes well into the rear diffuser and in combination with the springs could not come out. They also had problems with other bikes when trying to get a good lap but still managed to get 5th (3rd row).

The chamber was on the bottom pipe and that meant all the pipes had to come off to weld it. We opted to do a bodge job with rivets steel strips a hose clamp and lock wire.


The team were confident and that 5th position although not ideal they could pass at least 2 bikes before the first corner and then work on the others. Feeling pretty good about things we started the bike, and I headed off to Robert Holden corner to watch the race and they headed off to the dummy grid.

The bike never made it, it made a death rattle on the way and died as soon as the clutch was pulled.

My mate pulled the motor today and No3’s piston skirt had collapsed which was a surprise as it only had 5 hours on it. It could be that it needs reboring, it looks ok it will be measured before pistons are ordered.

Oh well only 12 months before we can have another crack at winning this meeting.

My mate riding his F2 did little better with a thrown chain leading to a DNF, however he did finish 1 race and managed 3rd in the Suzuki Series which has Cemetery Circuit as the last meeting.

Photos of the carnage.