Speeduino is now on Github Sponsors (Rather than Patreon): https://github.com/sponsors/noisymime
Help with building your Speeduino, installing it, getting it to run etc.
By kettlekev
This is the current tune file....need to rename to open
(73.19 KiB) Downloaded 22 times
This is the latest log file...need to rename to open
(12.67 KiB) Downloaded 18 times
I made some more earthing tests to day.

My bosch trigger (211) has individually screened trigger inputs and out puts. I was only earthing one end of the screen but now I have earthed both ends.

I have also run a wired earth to the speeduino case that links to the PCB 0v.

Both these changes seem to help but drop outs still occur at higher revs.

Plug gaps are good. The bike starts easily enough with a small misfire sometimes but that is probably where I have the cranking timing set, but once past that it sits at tickover.

EDIT. I did some USB cable tests and I think I am getting somewhere. A shorter cable seems to help with sync losses. New log attached with shorter cable.
(116.27 KiB) Downloaded 19 times
I will buy some higher quality cables and do some more testing.

Anything in my log or tune file I attached?

The cold advance table is retarding the ignition timing. You are only running with about 8*

I appreciate the advance table is a wedge shape, but the advance table doesn't look right to start with. However, it could have ended up that way because of the cold advance issue.

Perhaps zero the cold advance and start advance at idle at say 10*. Advance will be all in by 2500 - 3000 rpm.

Spread the rpm bins to reflect that. Set the 2nd bin in at the preferred idle speed, Make the timing trough (1st bin a higher value). That way it will help give extra torque for warm up. There is a feature for that, but if you do it this way first I think its easier.

perhaps zero the iat table to be sure. :)
Clearly like all micro's, if there is noise around it will probably generate issues.

After a couple of weeks of trials, the items below, in order of importance, seem to be what helps the most for a small space, bike design.

1. Resistor plugs (ones with a R in the code)
2. Resistor caps, initially I was worried about the additional 5k resistance but so far (pending dyno) they seem fine.
3. Silicone/carbon (not copper wire) ignition leads
4. The USB cable to run Tunerstudio live with must be high quality and not too long, also I found that using a couple of ferrites with at least one coil of USB inside, helped. Noise on the USB line will cause sync loss.
5. Wires between Speeduino and the trigger unit and from the trigger unit to the coils need to be screened cables. I use one for each coil feed with the earths connected at each end, which seemed better than a single ended earth.
6. The +ve to Speeduino benefits from a ferrite with at least 5 coils wound through it
7. The 0v to Speeduino also befits from a ferrite fitting

The latter two (6,7) need some more evaluation, as most of my problem was poor quality resistive plugs and caps and until I had those replaced, all of the above made improvements. I suspect that with quality plugs/caps, some of the other changes may not be required but again as a tight space build, they may still be useful.

Thanks everyone for the pointers. The real eye opener for me was the USB cable, I should have thought it would be an issue but didn't look there initially but it makes sense as its a direct line to the micro.

LPG2CV, I will review your last post next and let you know what I find. Thanks again.....
Last edited by kettlekev on Sat Mar 06, 2021 6:06 pm, edited 2 times in total.
By kettlekev

At the moment I am not using the IAT and CLT sensor inputs (injectors not on line yet, this phase is ignition only). So I have them resistor grounded to both simulate about 45c. With that being the case ( a simulated temp) why are the curves being used to modify advance?

But you raise a great point. I didnt even know there was a cold advance curve! I dont seem to need one as it starts easy but with fuel control added that could change so I best learn about it.

My normal spark table is;
spark with new coils.PNG
spark with new coils.PNG (49.37 KiB) Viewed 393 times
so my understand is that cold advance modifies these number +/- by a few degrees. The same applies to IAT.

So given I am not using either sensor yet, should I just set the advance offset to 0 across the temp range for both sensors?

This being a 2 stroke, I have no idea what the affects of CLT and IAT temp are and cant find much written about it.

With my sensors set at 45C, I assume my normal spark table will just run without mods if I set as below?
cold start.PNG
cold start.PNG (61.16 KiB) Viewed 392 times
zero them all. And you are set up for F* not C* :)

You should take time to go through all the settings ......

I saw your table in the tune you posted :)

Normally, I think the clt advance would be set to zero by default. It was set to remove 15* across the temp range, so no matter what you thought you set it to, it would retard by 15*

The reason it's there is to help stabilise idle. However, if you put the advance trough in the table, as the idle drops it get more advance which tends to stop it dropping and it evens out.

Adjust for idle - max rpm
wedge advaance table.png
wedge advaance table.png (121.92 KiB) Viewed 380 times
By theonewithin
Have you tried unplugging your stator/reg/rectifier?

I have 0 issues with noise on my bike.

And it will definitely be smaller than yours (145kg 250cc twin).

And that was using the 30 year old wiring which has no shield or twists on the VR wiring and I did nothing special.

Grab a radio and search for the noise.
By kettlekev
I did pull the alternator off just to rule that out.

The PC/Tunerstudio USB cable shielding was definitely a big help and decent plugs/caps.

Last test run today with the IAT and CLT compensation zero'd out then I am dyno ready again.

By kettlekev
Yes, much better thanks.

Slightly harder to start but that is expected.

My cranking setup is probably off at the moment I am assuming the same retard (24 degrees) as at the low end of my spark table and the rev cutoff is only set at 100 revs.

I think I will move to 28 degrees and up the rpm to around 500 as a starter.

The better USB cable (and better plugs/caps) has really helped the sync issues!!

When the new alternator gets here I will do a road run. :D

Thanks again.
EMI while cranking

Trying some different combinations, I've found I c[…]

… do I understand it correctly that the in[…]

Second injector bank

Read the wiki again. It provides the info you nee[…]

Yes, but input voltage is limited on some, such as[…]

Still can't find what you're looking for?