Anyone considered doing this upgrade? Doing some rough calculations that a 55mm throttle body would flow a bit more than the factory 32mm carbs would. It would be interesting to see if we could get a power improvement at all. https://www.ecotrons.com/small_engine_fuel_injection_kit/400cc_to_800cc_engine_fuel_injection_kit/
Very, very few have ever succeeded in converting to EFI. Here is one, and he is an engineer. http://projectcbr250rri.blogspot.com/2012/
@Midnightlight I have had discussions with the Ecotrons people and they weren't overly technical. I was chasing details about their small engine turbo kit (for another project that @Murdo is working on) and they seemed more sales orientated than support. http://www.ecotrons.com/products/small_engine_rhb31_vz21_turbocharger/ We (Murdo & I) will look at the Ecotrons EFI kit down the track as the SU-carbed Turbo ZXR motor is stage 2 of a longer term project. If you decide to go for the EFI, please post what you do and how it goes. Thanks Frank
It seems that all of his struggles are with mix and matching components to work together with an open source ecu. the Ecotron looks like a kit that would be much easier and having closed loop fuel control to boot. Reckon a kickstarter campaign would fund a efi kit for my bike?
There's plenty of kits out there. You can get an entire kit from Aliexpress for less than $500 delivered. http://megasquirt.info/products/diy-kits/ @Midnightlight are you thinking of putting an EFI system on a VT250F?
Megasquirts are recommended by the Land Cruiser 'turbo your 1FZFE ' guys .... or even just to piggyback the factory ECU, as its not programmable
A little back and forth from the Ecotron people and I got quoted $2000 US for a kit. Faaaaaaaaaaaaaaaaark.
Spend your money on doing a top notch carb overhaul and you will have the same power and a nice running bike. Well set up carbs will give good results (spend some time on a dyno) but the efi will only be of benefit if the rest of the engine intake tract is designed for it. To put the efi on a carb manifold will gain very little if anything power wise.
Pretty much "here's the kit and youll have to figure it out" i suppose id get more support if I bought the product but throwing $2000 US at a bike that is worth about $200 isn't a smart move. A MT-09TR would be a more sensible approach.
As Murdo said, you can give the carbs a good clean and she'll run pretty good. How does your VT250F go at the moment?
Starts with a tap of the button, idle is rock solid and all the way to 8k rpm its good but above there not much happens.
From the fuel tap there is a hose (see image below) that runs to the RHS of the motor and plugs into the carb boot of the rear cylinder. The Vacuum from that cylinder opens the diaphragm inside the fuel tap to allow fuel to flow. If you're not getting good vacuum or the pipe has some obstruction or kink, then fuel will not flow at the necessary rate. That might be okay at low revs, but might cause lack of fuel at higher revs. There's no real reason why your bike shouldn't rev out to the redline. Also, you might want to check the fuel valve filter is clear. They get pretty gummed up.
Ah i see what you mean, i have replaced my fuel vacuum line with silicone hose so shouldn't be too bad. I coated the tank with a coating and run an inline filter before the tap so we'll see what happens. Any experience with changing jets and why the front carb is a 102 jet and the rear is 100?
It was, I believe, because of temperature issues. The VT250F has 2 TCI boxes...one for each cylinder, so I guess the designers wanted to have different controls over each cylinder. I think you can run 100 or 102 in both safely. In my experience, the rear cylinder gets hotter than the front, but I run a modified airbox. I did have a VT that the Previous Owner had put 90 main jets in both carbs. It didn't go very fast at all! Vacuum hose: Be careful with silicone. The hoses are softer than the standard hoses (normally) and might pinch at high vacuum (IMO).
Well, finally got around to doing some further diag on the bike. Found the rear cylinder carb diaphragm wasn't installed properly so the slide would not raise. Took the bike for a ride and it picks up and goes like it should.