Sticky!

 

That's pretty cool. How does it run otherwise? I may have to switch to the Finbro ECU.

 

Mine runs like a champ. It just requires you run the right injector for your set up.

 

Mine runs great with the finbro ecu. Pulls real good. Set it n forget it style, i like!

 

i may have to switch over to it. So where would a person find a 68µF 25V electrolytic capacitor?

 

Gotta say, came home today, le grom had not been ridden in over a day. Hopped on her, flipped on the cold start switch, turned ignition on, tumbed the starter switch really quick and she sprang to life.

Instantly started riding, left the cold start on for about 2 min while she warmed up, then flipped it off and all was still good.


SO MUCH happier with this experience with the finbro ecu, I was so used to stock where you could get on it from dead cold and just go, and my cold start switch has brought that back.


I will be interested to see what its like in cooler temps as its been pretty mild around so cal this past week. (That video was shot when it was 60*F out)

 

I'll have to get it put on mine and try it. It's been down in the low 50's here. 40's at night.

 

So, who's going to be the one to assemble and sell a kit? I imagine there's a lot of people who would want this to retrofit. Perhaps Franco could offer it with the ECU? Or HR as a drop down option?

 

Personally, i feel like the Monkey father / Finbro / Franco of finbro, should go back to the drawing board, and use the US based grom ecu and put their programming on one of those to keep the stock auto enrichment. BUT because that is not the case a kit of something like this would be nicely included with the ecu and really its all of 5 bucks extra in parts. You could even go as far as not requiring any soldering by using a bigger DPDT switch that you could use blade connectors on so everything is just crimped together.

This solves a huge problem. I replaced the starter (wemoto) & the battery (shorai) and the cold start improved slightly meaning I didn't kill my battery starting it. It would still take 3-4 min. 1 min to put load on the battery, 1-2 min of cranking. Was a joke.
Thanks for this info. Does the 31 mm TB finbro sells support the high idol valve?

No idea, but i think the 31mm TB that finbro sells is simply a forza 300 TB, those stock do not have a high idle valve, but better they have an idle air control valve which actually does the job of the idle air screw and the high idle valve on our groms. That stated, this is a much more complicated piece of equipment and our ECU does not support this, so its blocked off on the "finbro" ones.

i may have to switch over to it. So where would a person find a 68µF 25V electrolytic capacitor?

Like the person above linked to any 68uF cap will work so long as its got some headroom above 12v (i would say 25v would be the lowest id go). That stated i got my 68uf cap out of an "assorted bag of capacitors" from radioshack.

 

This solves a huge problem. I replaced the starter (wemoto) & the battery (shorai) and the cold start improved slightly meaning I didn't kill my battery starting it. It would still take 3-4 min. 1 min to put load on the battery, 1-2 min of cranking. Was a joke.
Thanks for this info. Does the 31 mm TB finbro sells support the high idol valve?

 

Just bought a ECU so Subed.... for later use

 

Did you install dual valve springs? I hear the Finbro ECM revs to 12,500 rpm :crazy:

 

Yup the revlimit on the finbro is 12500.... for the stock 125cc and stock exhaust its pointless to run past about 10k or so, so nope i have not put dual springs in.

 

I just purchased all the parts to get this done, will hopefully do it this week after work one day. Still waiting on my exhaust so will be delayed in trying it out. fwiw, Radioshack only sells the 68µF cap in the mutli pack, can't buy them individually. We'll see if it's the same for my 8-hole injector/170 4v. The Koso 34mm TB I'm using has the high idle valve.

I would also suggest to add some hotglue or epoxy around the switch solder joints for extra security in regards to vibration, especially on this bike.

 

Definitely report back!!! The 68uf cap worked well with my pcx 150 injector, it might not be the same with the bigger 8 hole injector (though theoretically if its the same OHM rating the 68uf should do just fine) But worst case you go the variaty pack from radio shack and i think there is a 100uf cap in there.

And yeah On my switch i captured every solder point with some heat shrink then encapsulated all the connections in a big piece of heat shrink. Vibration disconnections shouldn't be an issue!

 

What size jumper wires is safe to connect these together? 18 AWG or 16AWG?

 

18awg will be more than sufficient. Highest current draw is from the injector and thats all of maybe 1.5amps at absolute most.

 

What kind of diodes should be used for this setup?

 

MacGuyver (aka nd4spdbh) suggests you use any standard silicone diode: 1N4001 for example.

 

Just fit the finbro ecu and although it starts ok now, i think it is going to need some help in the colder months.
Anyone got pics of their cold start switch setup, im not too good with electrics and would like an idea of what im up against
Cheers
Jay

 

 

View attachment 26795

Off topic, but hows the fitment of that wrap? Ive been looking for one for a while and i see they have a lot of them. Just curious as to the quality/etc.

 

Many thanks fella, is your setup using the cel light as an cold start indicator.
I know im a pain but has anyone got pics of the componants connected ie the diodes and cap.
Thanks
Jay

 

I'll build a schematic, stay tuned..

 

OK grommers, this is one way of building the finbro cold start fix circuit, including the CEL on/off indicator. Pardon the crudeness, but I have no access to any illustrator software, so camera pics only.

Please make sure the diodes and capacitor are in the correct polarity (do not reverse) or else KABOOM. It's easy to check it. Each diode will have a silver band on one end. The banded end is the negative or ground. The capacitor has a negative (-) label with a directional arrow. Follow the label to ground.

Solder or crimp, use whatever method you prefer. I crimped all my connections to make it easier if I ever wanted to return to stock. And don't forget to add the heat shrink tubing as you make the connections.

Special thanks to Nd4spdbh for bringing this to light.

Parts list:
wire stripper/crimper, 18AWG stranded wire, cutter, lighter or heat gun, heat shrink tubing (make sure it can fit over the capacitor), T-tap, various male/female connectors(spade, fork, ring, crimp), DPDT switch, electric tape, 2 X diodes (1N4001), 1 x 68uF electrolytic capacitor.

The two middle prongs on the switch are both connected to ground.

 

Nice but I dont see the issue, just open the throttle a tiny bit for 10 seconds and its good to go? Or are people having other issues? My 235cc has always started fine with a touch of throttle (only been down to 32 degrees tho)

 

The circuit described in the thread simulates an enrichment circuit, you are sort of manually simulating a "fast idle" circuit with the throttle. I think the circuit here is a clever solution to a problem that I'm surprised exists in an aftermarket ECU at all- I would have thought that it would have a "cold start" factor in its fueling equations, since that was a standard feature in the open-source ECUs 15+ years ago.

 

I'll be doing this as soon as I actually feel my bike have an issue to start..at what temp do you guys think you start seeing cold start problems..here in central Florida I have yet to have an issue starting the bike with this ecu..and I love the adjusted rev limit..especially when I'm turning off my street onto the highway...that little extra allows me too get out of my turn without hitting the limit.

 

I was thinking about that myself. I wonder if it has to do with the ECU's coming out of Thailand. My brother used to live there and he said it was hot most of the time. I might be way off, though.

 

You're exactly right.

The ECU comes from a Thailand domestic Honda which doesn't have (because it doesn't need) a cold start circuit.

 

Makes complete sense. When I was working on an old RX7 that had an intake air leak from someone doing an incorrect emissions system removal, I saw a lot of guys marking up the carburetor diagrams for part removal saying "remove this fast idle crap, why would anyone want that?" Of course they all lived in Florida.

 

Set the idle higher. My finbro will start and idle at 3k then drop to about 2k. I can make a video if you'd like.

 

That's fine but 2k is too high. It also wouldn't have helped mine start, it wanted a richer mix not just more mix. Opening the throttle never helped anything.

 

2000 rpm is not too high of an idle for a big bore cammed air cooled single cylinder?! Especially without an oil spinner (flywheel mass) and high compression. My aprilia SXV 550cc vtwin idles at 2000 rpm hot. Actually before I adjusted the idle on mine I do recall it starting then immediately stalling when cold. Once the idle was set to ~1900 hot I have a first start every time. It will drop down when cold and studder a bit, opening the throttle and revving to 2500-3k for 10-15 seconds or so would fix it. Again its awesome your making a cold start and what not but if people cant handle getting a bike making 2-3x its original horsepower to start and idle they should move on and buy a larger bike that makes the power they need stock. Thats not directed at you a_morti. You are doing this for convenience and as a project I think. I just keep seeing way too many people complaining about the finbro stuff without any exp.