What did you do today? Cobba's rebuild

[cobbadiggabuddyblooo]

http://www.trx850.com/phpBB_forum/viewt ... =6&t=10897

Next mod finished was new waterproof terminal blocks fitted to the wiring harness.
I also wired the coils to draw power directly from the battery.
1,000km service with new oil and filter and checked clearances.

But my shim kit goes from 1.65 - 2.20mm and I need to get a couple of 2.25, 2.30 and 2.35mm shims just in case I need to go up on a couple of the exhaust clearances next time .

Just a slight weep of coolant from the head gasket over the last 500km with spirited riding but it's not corrupting the oil at all.
It only leaves a slight trickle the length of the barrels and the radiator level has stayed consistent and day to day riding shows no weep, and only appears as mentioned after half a tank of spirited riding .
My own fault though as didn't think about the couple of dry runs during the rebuild had work hardened the copper head gasket
I'll just remove the head again, re anneal and hylomar sealant the gasket and all will be good.The head and barrels both had a bees dick taken off them to make sure I had a clean,flat surface to start.
Be a good opportunity to just check all is well inside.
Got this task down pat as it's just the next stage if checking clearances , just unbolt the head and can be finished in 4-5 hrs.

I'll finally get around to checking float height this week and in 2 minds on setting the FCr's up with flex jets
Next task at hand will be finishing off setting up the O2 sensor gauge mount and wiring this into place.
Jet kit I ordered arrived the other week so I have main fuel and air jets from 140 to 170 fuel in 2.5 increments & 180 to 220 in increments of 5.
Found a guy local who does dyno runs once a month for $44 on a Saturday as a social event so I might sneak one in as a benchmark using the std FCR and default ignitech settings.

http://www.trx850.com/phpBB_forum/viewt ... t=flex+jet

[cobbadiggabuddyblooo]

RED line is the 3 degrees retarded map and the GREEN being the std Ignitech default program with TPS.

So forget about my retarded map theory as you can see there is a constant loss all through the HP and torque curves and even the air fuel.
But I can see why Sanddunes lost his midrange as maybe the Ignitech map can be advanced a little more over 4000rpm.
Trixed did an A-B run on his stock TRX with the std ECU and the Ignitech and you can see the gains under 4000rpm and again over 6500rpm.

I will question the Nm result and originally it was in Ft/lb and he asked me after the run was completed if I would like it in Nm for the print out.
80Nm is only 59Ft/lb and a loss from my stock motor with FCR result of 87Hp 62Ft/lb result.

80Ft/lb is 107Nm and 104Hp which sounds more in the ball park looking at other dyno results in similar format.

CORRECTED SPECS AFTER RECALCULATION OF DYNO TO Nm
104hp at 8500 and 71ft/lb at 6700rpm

http://www.trx850.com/phpBB_forum/viewt ... yno#p98812
If you view spandons map you can see he found 100Nm torque too.
The Husky 900 Nuda puts out 105hp and 100Nm too.

[Killerwhale]

The green is pretty much exactly what mine pump out on the rear.
94.6 Nm
I might want to try the standard ignitech map then

[cobbadiggabuddyblooo]

Installed a revised ignition map today and bike sounds better, I have my smooth unloaded gear changes back and bike just wants to rev faster and keep pulling after 7,000rpm when you twist the throttle . It's taken away the slight vibration I was getting through the pegs and bars so it's all slowly falling into place.
My O2 sensor kit arrived 5 minutes ago so looks like I'll be doing a little rewiring with the new loom through the week.
perfect as they are predicting rain anyhow.
So I can see if my assumption of lifting the needles was only feeding the default TCIP4 curve which is now working as an advanced timing map due to the higher compression.
More fuel making for a slower burn, richer mix to compensate for the advanced timing to get timing back to optimum. Not the way to go about things.

So I'm very happy with the timing improvements with this new program.
Now it's time to check my air/fuel ratio..

So what have I learnt today...
Assumption..
Yes assumption no consumption ..
Two vital mistakes. I lifted the needle to give me more fuel and changed timing at the same time.
Whatever gains I felt and assumed it was timing was more like the result of more fuel.

Next dyno run I'll try with a slightly richer air fuel mix and default IGNITECH map.
This way I can get another torque curve to dispell any doubt there too.
Something to shoot for and book in for next months dyno day.
The dyno guy did a couple of extra snapshots with different throttle and rpm readings for me too so I'll see how the Air/fuel gauge system I have set up compares to the dyno results.

If I gain some with a different A/F ratio next month, I'll book in to see if I can sneak any more out of the timing.

I'm sure there are a few sitting back with a smile on their face thinking I told you so but that's all apart of my learning curve.. Sometimes you have to stick your finger in the boiling water and go #€UK that's hot

[Kenny]

Great work Brian as usual. Did you get Trixed's graph so we can see the difference's?

[cobbadiggabuddyblooo]

Ok I think maybe I can see where the confusion is coming in here on torque readings.???
You can see on the dyno result there is a HP reading that finishes on the RHS around 95Nm but this needs to be read on the LHS which is HP.

The Nuda 900 figures are quoted at the CRANK no the rear wheel so you would look at a ballpark of 87Nm and 92RWHP.
The Nuda has a longer stroke (81mmx80mm) so you would expect a higher torque figure and lower HP reading.
I'm also running a lighter rotating mass so again this may factor in why there is a little less torque.

Looking at my other dyno results.
Stock motor with staintunes 76hp and 59Ft/lb
Stock motor/ FCR's and l/bore. 87hp and 62Ft/lb
Trixed std TRX result today. 72hp and 49Ft/lb (fuel ratio issues)
So today's result of. 104hp and 59Ft/lb can not be correct.

Udaysen should post his results up shortly I would imagine.

A little homework and gentle reminder to kick my butt with.
This link explains what I have achieved with the power/torque curves.
http://www.epi-eng.com/piston_engine_te ... torque.htm

[cobbadiggabuddyblooo]

Was over at the dyno shop today and explained it all to him and showed him the corrected result.
He said, AAAAhh that will be why a few people had mentioned it was down on torque than expected.

Latest toy is up and running so now I can tinker with the jets to get the fueling right where I want it.
Good thing is I can get a few values as days are cooler here now so I can get my base reading which is just a touch lean with the default 150/200 mains and needle in the mid position,
So come summer they may be just what I need due to the warmer climate.
Average temps now are around the 22 to 26 degrees through the days and 10 degrees cooler so if I set it up now to 13-12.7 it may be a tad rich come summer.



I'll calibrate the throttle position with a few white lines on the throttle tube body to designate a throttle value and a mark on the grip so I can see the influence of jetting change- A/F ratio to throttle position.

[Trixed]

Great work Brian as usual. Did you get Trixed's graph so we can see the difference's?

Hi Kenny,

My results are on the Dyno Day thread if ur keen to see the difference.

[cobbadiggabuddyblooo]

Started a little tinkering and got a few readings today with the O2 sensor.
I put a 20mm long piece of white tape on the throttle grip by the body and placed a black line as a reference pointer.
Then placed another 50mm piece of tape on the throttle mounting body and marked my 0% 25% 50% 75% and 100% with a small red dot in between to give me 1/8 references.

Note 50mm long tape gives me 0%-100% at each end due to the 60 degree throttle I'm using.
If running a std throttle twist this length would be around the 80mm mark .

Carby's have been balanced and float levels set previously.

So my fuel screws are both set,
No.1 is at the std setting... 1 turn out ...and No.2 is screwed... 1/4 turn in..from std to just richen this cylinder to get me both hovering about 13.2.
(this screw is accessed through the hole in the fuel bowl body close to the inlet manifolds )

Riding in traffic and using 1/8 throttle 2nd to 4th gear I'm at about 11.6 to 11.8 and running from idle to about 4,000rpm.
A little rich so I'll try to screw out the slow air screw from the std 1.5 turns out to add a little more air and see if this leans out my readings closer to the 12.5/ 13.0 mark.

Screw the throttle from 1/4 to half throttle from 2,000 upto 4,000rpm I'm happy with a reading about 12.6 -12.8.
but open the throttle any further and I start to find the 13 and over readings with 13.7 a constant from 1/2 to wide open throttle through the rev range.
This only confirms what readings I was finding from the dyno run so calibration of my own sensor and the dyno sensor are reading the same.
(note.. There is a simple couple of steps to calibrate a sensor built into the Innovate gauge so as the sensor ages or I change it for some reason, recalibration is not an issue )

So tomorrow I'll change the main fuel jets from the std 150 to 155 (accessed through the fuel bowl bung)
and screw out the slow air screw another 1/2 turn which lives by the main air jet right beside bellmouths.

I'll see what readings I find and post them tomorrow.

[dandywarhol]

I'm no dyno expert by any means but dyno runs are conducted at WOT (wise open throttle) and running solely on main jet.

Your last readings just above half throttle are not fully on main jet Brian and would be a bit rich by my reckoning for normal running through the throttle range.

Stoichiometric/Lambda 1 air-fuel ratio is 14.7:1 by weight, anything less than this isn't properly burning all the fuel efficiently. The figures of high 12s is fine for under acceleration and producing max power but how often are you running at full throttle apart from the track?

[Killerwhale]

You should always as for example as AF1 go thru the rev range and check it all, if you find more power down low you for sure reach max faster:

https://www.youtube.com/watch?v=LZl5yX3_0yg

[dandywarhol]

You should always as for example as AF1 go thru the rev range and check it all, if you find more power down low you for sure reach max faster:

https://www.youtube.com/watch?v=LZl5yX3_0yg

Yep, rev and load range, unless the bike is purely for track use and low throttle openings aren't too important

[Con Rod]

12.5 is certainly the sweet spot under load but you can stretch to high 13s for unloaded freeway work and get stonking fuel economy

I would suggest you might want to tune your carbs on the stock ecu then tune the ignitech box once you know your fueling is right, just to simplify the process. Long hills are you friend for wide open throttle but a lot can be done just on city roads and freeway

[Con Rod]

oh and mains are easy enough to set, as is the fuel screw, you will do everything on the needle jet. Not sure how the fcr work but with the stock carbies I ended pu making varying thickness washers for the needle to fine tune

biggest problem of course tuning the stock carbs is that the needle jets are constantly wearing and a good setting turns rich in 5000km

[cobbadiggabuddyblooo]

Thanks for the input guys,
That's the beauty of a O2 sensor i have a constant A/F reading at any revs, throttle position and load.
Yes thats true dyno reading are at WOT.
I find any throttle position from about 1/3 to WOT gives me a leaner mixture.

Following the FCR tuning manual, I need to get the main fuel and main air jets right at WOT before addressing the needle.
I've placed in the 155 mains and I'll read this through the rev range at WOT.

From around 6500 to 9000(limiter) its pretty consistent at 13.7(+-.1)
If I get a similar line just richer ( 13.0 for example) with no change at the end, I'll know the 200 main air jet is suitable for a 155 main fuel.
If it leans out right at the top,( eg. 8-9000rpm)I'll try a 190 main air and visa versa, if its a little rich right at the end, I'll try a 210.
The main air also can influence how the fuel atomise's due to how the FCR's work through the emulsion tube.

I've a jet kit that gives me from 140 to 170 in 2.5 increments and main airs from 180 to 220 in increments of 10.
I can feel the richness down low and partial throttle, the ACC pump shot will give me a momentary high 10 reading.

It would be great if there was a program that could combine the 3D map from the IGNITECH and RPM/throttle position combined with the A/f from the O2 sensor for a real time reading and just study the data.
This may help understand if the little flattening of the curve at 5,000rpm is fuel or timing related.

I'm currently running the default program just with 8,000rpm advanced by 1 degree and 9,000 by 2.
The torque curve on the -3 map that I advanced at the top end actually closes and shows improvements but the a/f on both remain constant.

I've got a book with a grid on it with rpm from 1,000 to 8,000rpm down the side with 1/8 to 1 throttle positions along the top.
I'm logging my readings with light load and heavy in each gridded box as my reference.