What did you do today? Cobba's rebuild

[dandywarhol]

Is it possible to start a new post, making it a sticky, where folks can only post programme maps?
Carpe TDM do a similar thing for Power Commander maps.
There would need to be a disclaimer as a suffix in case some nutter fecks their motor!!

[dicky]

Is it possible to start a new post, making it a sticky, where folks can only post programme maps?
Carpe TDM do a similar thing for Power Commander maps.
There would need to be a disclaimer as a suffix in case some nutter fecks their motor!!

Ta DAH!

http://www.trx850.com/phpBB_forum/viewt ... =6&t=10857

[cobbadiggabuddyblooo]

Today's feedback after 100km run up over Mt Glorious and back.
No more popping on roll off through the exhaust , pulls like 2 trains now from 4-7500 and onwards
A little fueling issues down low but definately found improvements.

[Trixed]

What was the cause of the popping u think?

[Con Rod]

a little burbleing / popping on the over run is not a bad thing but heavy backfiring is likely due to too lean a condition or the enrichening valves on the stock carbs not working.

It is not unusual to see cracks in the valve on the right carb as it is exposed to the sun and weather when the bike is on the side stand

step 1: Inspect the plugs, if popping a lot, one or both and likely going to show a lean condition
step 2: Check to make sure the valve is working fine
step 3: move the needle clip back 1/2 a space (use the washers)

[cobbadiggabuddyblooo]

Std carbies What are they

[Con Rod]

you could then run a slightly larger main jet or extra 1/4 tunr on the fuel screw to compensate if there is no en-richening valve

I dare say that will better flow through the engine with your valves and exhaust a bit of popping is to be expected.

Still not really and issue, I like a bit of burbling on closed throttle

[NWS870R]

Today's feedback after 100km run up over Mt Glorious and back.
No more popping on roll off through the exhaust , pulls like 2 trains now from 4-7500 and onwards
A little fueling issues down low but definately found improvements.

Are you running with TPS or bypass Cobba?

[cobbadiggabuddyblooo]

Running TPS and TCIP4 IGNITECH programmable ignition.
Just retard the map -3 and I feel I may be able to go -4 a little either side of 4000 with the Akra system, kent cam set up which is around where they both work in unison. Good velocity and scavenge in the midrange which is what I was aiming for.
17/41 gearing and 3rd-4th gear at 5000rpm just when you go to WOT it performs just how I want it to so now correct tyre pressure is critical.

[dandywarhol]

Tiniest of exhaust leaks at joins before the cans can cause popping

[Trixed]

Std carbies What are they

Do have a bit of burbling on throttle roll down. I have entered the magical world of Fcr s lately as u know and loving it. Not to mention also getting 20 km per litre over std carbs. More power and better fuel efficiency. Don't think it is lean as the main is a 150. Been two weeks or so and the fcr with the tps calibrated is running like a Swiss clock.

[Rod.s]

Std carbies What are they

is running like a Swiss clock.

Wow that bad

[alextrx850]

[quote="Trixed"

Do have a bit of burbling on throttle roll down. I have entered the magical world of Fcr s lately as u know and loving it.

Good to hear youre now on Keihins..

[cobbadiggabuddyblooo]

So my wasted spark will be firing 3* later in the exhaust stroke which is a 9 degrees after the exhaust valve is at full lift (now 12 after full lift). , maybe this has something to do with the why all of a sudden after changing the timing, I've lost a fair bit of the popping through the exhaust.

Now do they change the phasing on the trx when wasting spark, this will give a much weaker spark jumping from the plug wall to the electrode??
I'm waiting for a reply from Ignitech on this question and post the result shortly.

[cobbadiggabuddyblooo]

For those interested on options on how to retard the existing map and still keep the same curve, here is the response from Ignitech.


Hello,

You can solve it with three possibilities :

1) put new map decreased about 3°
2) use parameter "correction" with value -3° (for both cyl)
3) increase base advance value about 3°

We recommended 1)

Regards.

Jiri Krejzl
IGNITECH