What did you do today? Cobba's rebuild

[cobbadiggabuddyblooo]

Was just about to text you.. Dave threw the air box mount in the bin... sorry mate...

[dandywarhol]

Next you'll be getting one of these made up....

http://newatlas.com/drum-charger-cheap- ... rbo/46648/

........and inconspicious

[cobbadiggabuddyblooo]

http://www.motorcycleproject.com/text/plugwiretech.html

New HT leads and couple of sets of plugs arrived today and thought I'd add this link for some added info...

[cobbadiggabuddyblooo]

Packard 440 7mm tinned copper core HT leads with an extra 3mm silicone shield around it.
New DPR9EA-9 plugs set at 0.85mm gap..
It's time to ride.. 26/01/17



Track day at Lakeside planned for the 10 Feb and the opportunity to do a little tuning.
Morning sessions I'll utilise the O2 sensor because the last 2 yrs when I've been able to ride was mid winter so I'll take my carby spares kit with a choice of mains and pilot jets and see how things go.
I've also redirected more air in under the tank so it will interesting how things pan out.

Then the arvo sessions can be used to tune the tyres/suspension ....
New Dunlop D211's GPR's and steering damper fitted plus gearing changes from down 1 tooth on the front from 17/41 to 16/41.
I've also got a spare rear sprocket set up on a seperate spider with a 40 tooth rear if 1 need another 10kph down the straight / drop the revs a couple of 100rpm.

Hopefully I can sort most of this out on the day so I can enjoy another trackday on the following Saturday 18th again at Lakeside.

[cobbadiggabuddyblooo]

Fitted up the Gopro today to record the RPM, O2 and throttle position with the lower gearing too.
First thing noticeable was the digital read out on the 02 sensor must flash around the 30 frames a second mark because when viewing the video afterwards I never got a constant read out showing the 3 digits (eg 12.6 )

I may have to try another setting in the camera instead of 1080-30.. maybe 960-48.. 48 frames a second may capture all the numbers ...
At the moment I can pause the video frame by frame and capture the A/F ratio...
Air temps today are 35* and a very hot North westerly breeze compared to last winters milder 28-30* and cooler SE sea breeze.
The updated air intake feed plus the tank raised 10mm and filter fitted fed more air in under the tank compared to the last test in winter when last A/F ratios where taken.
(lower tank height No filter different air feed).

Today in the lower gears I had good constant mid 12's through the rev range and it would climb up to 15 from peak torque to peak HP (7500rpm to 8500RPM) which was just a tad higher to previous readings I had at 200kph plus last winter in 4th and 5th gear.
( 14.7 at peak and force fed a lot more air due to the speed.)
So I can see the possibility of fitting larger main jets when recording settings on the track day next Friday because I'm predicting I'll run well into 15's + and leaner down the straight in this set up.
Plus I'll discard the air filter too on the day so no restrictions...
First thing I noticed too it was running leaner around the by 0.5-0.75 at the 5500rpm mark where before it struggled just bouncing either side of 12 on the A/F ratio.

The amber shift light in the photo indicates peak torque , I've set red for when I reach peak HP
The small LED's running around the circumference of the A/F gauge show either side of stoichiometric (15.1 ) at 12 o'clock


Acceleration is 12.5 from 4000rpm and once I sneak over 6500rpm I'm finding high 12's - low13's 7500rpm I'm into 14.5 and low 15's / 8000rpm +

Reading at this point was 12.9





The other noticeable difference was on over run it would run into the 15's and flash 16 every now and then so I may have to screw in the air screw.

I might try running a smaller main air jet down from 200 to a 190 or 180 first on the track day to see if that gives me improvements instead of going straight from the 163.5 main fuel jet and trying a 167.5 or 165.
Main air jet is accessed on the air intake side of the carbies too so an easy 5 minute job.

[dandywarhol]

I wouldn't be concerned about the overrrun readings - as long as the pilots are doing what they should be doing on throttle would be more important IMO

[Con Rod]

I wouldn't be concerned about the overrrun readings - as long as the pilots are doing what they should be doing on throttle would be more important IMO

yep completely agree

would expect it to lean out and pop on the overrun, so not a worry. Main thing is just not going too lean under load, it is fine if it lean out cruising as you are getting great fuel economy, provided its not over heating

the aldi boroscope comes in very handy for getting a look at the piston crowns to make sure they are not getting too hot

[cobbadiggabuddyblooo]

Yes I can see the sense in those responses .
I was thinking with the higher compression a slightly richer mix would just keep things a little cooler to keep residual heat on over run in check.

[dandywarhol]

Yes I can see the sense in those responses .
I was thinking with the higher compression a slightly richer mix would just keep things a little cooler to keep residual heat on over run in check.

You aren't producing power on overrun so I wouldn't see excessive heat being a problem at these ratios

[cobbadiggabuddyblooo]

Changed settings and increased to 48 frames per second on the Gopro so now I get the complete reading on video....
I'll mark the throttle housing and grip with some white tape to show throttle position for the track day recording.

[coxylaad]

datalogging - its the future!

[cobbadiggabuddyblooo]

Fun and games at the track day today. coolest day of the last 2 weeks at 33*c but a hot breeze and was having trouble with body temp so the first 2 sessions in the morning I was pulling in to the pits after about 8-10 minutes. I sat out of the 3rd session and then went for it again in the afternoon.
I'd start by pouring water all over my body before getting into my leather and the first run after lunch through the back section and bus stop I'd open the visor to get a blast of fresh air. Next time out I found the jel pack in the freezer bag and put that between my back brace and singlet and I could finally manage the stress from heat and finally was in the thick of it giving most a good run for their money in the final 2 sessions.
Pretty happy with the Dunlops and would leave the bike in the sun in the arvo session to keep the heat in the tyres.
I was surprised just how well this worked and into the 3rd lap things felt pretty good compared to the morning when I'd pull in under the shade after the session. It wasn't until the 5th lap things would start to work.

Big thanks to Marko and Udaysen for making the effort to come out for a few hrs in the morning....



3rd Gear



4th GEAR



5th gear

[dandywarhol]

You thought of fitting a drip feed from your sweat glands to the carb intakes for water injection?

[marland2]

Was great to be there Brian, really impressed just how hard you were going, as you said the heat was taking its toll. Was interesting being able to hear your exhaust note from all the other bikes while you were out of our sight on the back esses. Some riders were quicker on the main straight but you sure gave it to them on the corners. Great stuff. Oh and thanks for the shot of my van in your 3rd gear photo. Cheers Marko.

[coxylaad]

do you have any problems with the tyres overheating in that temperature?

if its 33 degrees air temp and sunny the track temps must be astronomical! (well compared to any track day ever in england)