Yamaha TRX850 Enthusiasts Forum

Overlord Neil wrote:I can't spray my worms probably...

I also get a case of trouth mubbles sometimes

Neil,how did the new map work out.

OzzieDave wrote:Neil,how did the new map work out.

It masked a bigger problem (inlet cam has been installed 3 teeth out), I had the bike in bits since so couldn't say. Looking at the map it looks ridiculous, I think Cobba mentioned it was too far out to be of any use. It did 'work' but as for the start of a performance improvement I think baby steps from a standard baseline is the way forward.

You can get an 'advancer' for my old ZZR600, they do several versions a mild at 4° advance and max at 5° advance, which speaks volumes. I need to read up a bit more about timing and advance.

has anyone uploaded any maps to anywhere yet?

I can hold the files if required.

I just found that the OVER ignition unit 'just' does a 3* retard over the whole curve.

interesting to know.
It seems ignition timing doesn't seem as minutely critical as fuel injection mapping.

Yep that's right Robert.
3* but the Over ignition is for the kit which includes 12:1 comp pistons/cams/exhaust/ FCR's.
The TDM 850 Over originally ran a std ECU and it was retarded 3* by manipulating the timing mark at the rotor.
You need to get your fueling optimal before looking at ignition timing.
Get your fueling wrong and too lean you'll cook your motor plus a too rich or too lean mixture burns slower so this impacts on ignition timing.
Got your fueling correct and timing wrong and too much advance it will kill your motor or too retarded you'll place extra heat stress on exhaust valves and headers.
With carbies that will take a little time as your intake bell mouths, spigot length, choice of cams and exhaust all impact on volumetric efficiency and this all impacts on an optimum ignition timing map so this if done purely by dyno times and track time.
Or set up your own Sensor set up.

Mapping your fueling via the sensor readings with fuel injection makes the job real easy and it will compensate for the environment and conditions your riding in.
Once you set your A/F ratios to how you want to tune the motor ( acceleration, power, fuel economy etc) the sensors keep this constant to any changes in air density and altitude.

If you look at the ignition map killer put up a while back it's nothing like the std map or mine due to how it's been set up and specs.
If I ran his map it would destroy my motor.

Finding someone to reflash your fuel injection ECU is a dime a dozen with knock sensors, O2 and MAP sensors doing the hard yards for them but getting someone to set up your carbies and time your ECU close to optimum with a carby motor is as rare as rocking horse shit now days.

Hey all,

I've just installed TCIP4 in my 1997 TRX, it's almost completely stock apart from a Bafflectomy. It has 52,000 miles on the clock, I recently finished a top end rebuild (valve oil seals, piston rings, reseating valves ect) so thought the TCIP4 could be justified once it ran smoothly, the low rpm first gear throttle jerk was doing my head in.

I programmed the TCIP4 with the TDM850 preset option, I did have to change a few things initially;

- Tachometer out put from 2 pulses per revolution to 1 to get a accurate reading
- Used the Tachometer test function to calibrate the read out (-4% correction)
- Revolutions without ignition from 1 to 0
- Calibrated the TPS sensor 0% and %100 ranges (but left in the sensor no option)
- Set the limiter from 11,000rpm to 10,000rpm

- See here for screen shots of all the TCIP4 program tabs with the settings I'm currently running: https://drive.google.com/drive/folders/ ... sp=sharing

Now here is the problem (apologies in advance if its glaringly obvious).
The TCIP4 dose eliminate the low end throttle issue and generally feels more refined on the standard TDM 850 map. Unfortunately this is only once the bike is up to temperature (reading 60-70c) if its taken above idle before hand (+1400rpm) and or under any load it produces a stutter clunk and momentary loss of power. Obviously this is alarming and unpleasant, I've swapped back to the stock ECU and the problem dose not persist. I'm thinking that what I'm hearing is knocking/preignition but I don't have the expertise to properly diagnose let alone start tampering with the advance.

Has anyone had a similar experience?
Have I missed a basic setting in the TCIP4 software?
Could I solve this by adjusting the advance at low rpm?

Any and all advice welcome, many thanks. D

Use the choke for the first couple of minutes until bike is warmed up.
Richer mixture will burn slower.
Can't have your cake and eat it too when cold as temperature doesn't dictate the engine timing on the program so something has to be compromised.
Check the air cut out valve covers on the carby as they may be leaking. If they haven't been replaced, it will Be well and truly due. They may look ok but plenty have found this is the root of all evil in low rpm issues.

I have been having the same problem, rev limit set to 8000rpm, std map with tps set.
At around 2500 rpm in 4th gear, rolling the throttle produces shuddering, again not with the std ecu.
I repaired the carby cover some time ago, all of the vacuum hoses have been replaced, along with fuel hoses and the carby mounts. Have checked to ensure no water in tank or float bowls, carbys have been balanced.
Though I have not inspected the carbys as yet.

You repaired the air cut off valve covers Dave??? A number of guys have tried repairing these covers to no avail and once replaced with new covers, it sorted the problem.
Pilot curcuit runs slightly rich to start as it should so timing will accomidate a little advance. If your still leaking air you'll have a faster burn.
Try turning off your TPS , problem is still there, try reducing the timing at 2500 rpm by 2 degree incriments until the problem is no longer there.
When you turn on your TPS look at your throttle % and the most advance is between 5-20% so do the same here and decrease in incriments until the problem goes away.
Remember 4 th gear at 2500 is under a lot of load and everything has a threshold.
Weak spark could be the other cause.
Check you battery voltage and charge under load and if all good , simply wire in a relay to boost voltage to your coils and increase your spark. So you'll be sticking 14 v up there date hole.
Check the coil earth too has a good clean healthy contact.
Ignition won't be the problem because it works at 2500rpm in other gears.
It's under a certain load and your pilot curcuit will still impact on your fueling here and more so due to the nature of CV carbies compared to FCR type mechanical carbies.
If it's not fuel related ( including octane rating, double whammy because it will pre ignite earlier plus lower octane fuel burns faster) or timing related, it will be spark related and not strong enough.
Decarbon your chamber too , there are a number of additives you trickle into your air intake to do this. Even a tiny water feed will produce steam in your chamber and clean things up too.

The rh cutoff valve cover was leaking, I used super glue to fill the cracks, then painted with black paint. This was prior to fitting the Ignitech unit, it resolved the problem and it has not happened again.
I have designed and had printed a replacement using a 3d printer, but have not fitted it yet. I have not been able to find any for sale online.
I have had fitted your suggestion of using a relay to supply the coils directly from the battery for quite some time now, it does make starting much easier.
I have a digital volt meter fitted, It shows 13.4 volts approx with the headlight off, at just off idle.
I use std 91 octane unleaded.
I will try your other suggestions once the valve clearances have been completed.

http://www.kedopartsaustralia.com/air-c ... st38-carb/

They're the ones most of us have used.

91 octane ... That's more than likely your problem, run 95 or 98 and this will elevate the problem.
4 th gear at 2500rpm under load is more than likely taking you into detonation otherwise time your bike to run on 91 octane fuel with the trade off of less power.

I will try a higher octane once it is back on the road.
Kedo did not have any covers in stock the last time I looked, that is why I went the 3d printer route.
I have had several made, so will try them out first.