A newbie looking for help with a CRF450R

[saber63]

hey guys i just wanted to say that Ive been looking at playing with a micro/mega squirt for at least 3 years now... but never did take the plunge. but now is looking like a good time!

a bit of back story, I'm building a custom bike, with a custom frame, my motor of choice is the 2003 CRF450R motor, now don't worry i installed a new stator, so i have 12V out. however only about 45watts ish at idle... but i don't want to have to mess with the carbs!

Ive found an TB thats the same size as the carb, and has some stuff built in like the TPS. i also know i need a MAP sensor, IAT, wide-band, and maybe even an EGT and lastly an engine temp sensor

however i foresee some problems... I'm pretty sure it being a kick start could be a pain. secondly I'm pretty sure it uses the 3 small and one large bumps on the flywheel for its spark timing, using i think a hall sensor but maybe a VR sensor?(im not sure)

i must also control the spark as the original system uses the TPS sensor... and i must confess Ive always been a bit confused about how the squirts deal with spark

and one of my most recent concerns is a fuel pump... with only a 45watt stator, and a 35watt headlights... i only get about an amp to two to play with at idle (or fear running the battery dead) mind you this motor is at least 40hp, and maybe as much as 50 or even 60 (depending on how much work i do to it)

the only saving grace is its just a thumper with one spark and one injector

what say you wizards of the "squirts" should i go for it? or should i just stick to swapping out needles and jets?

thanks alot for any help you guys can offer!

[Andy_Stprbeck]

Search for "MYK777" on here and the megasquirt forum. Lots of good information about overcoming the difficulties of speed density on a single cylinder. He has a YFZ450 quad.

Your stock ignition coil is probably a CDI coil so it will not easily work with microsquirt. Honda CBR600F4i coils are pretty easy to come by and there is information about them on these forums if you search.

Suzuki LTR 450 quads come with a very small externally mounted fuel pump. The aluminum housing they come with is kind of heavy and the fittings it comes with are kind of inconvenient to deal with but there are fittings made for the LS6 fuel rail that happen to work. Don't know the current draw of it though.

I've been told that the fuel pump from a Honda 680 quad is a nice unit, but I think it's physically pretty big because it comes with a swirl pot and pressure regulator, might not be able to find room for it on your bike.

If you're willing to make an in tank pump work I'm told the Suzuki RMZ450 pumps are very low current, no idea if that's true. I imagine fuel pumps from any of the new fuel injected motocrossers would work but probably expensive.

Also for what it's worth, I'm pretty sure you could share the throttle position sensor with the oem ignition system if you don't want to deal with the complication of controlling spark. From what I've seen on these forums, spark is the hard part.

I'm still in the gathering parts and information stage of my project (well, actually more like the gotta get other "crap" done first stage) so can't be a whole lot of help but hopefully this is something.