YFZ450 EFI Conversion

[LycomingHunter]

Hey guys,
Just started school and I'm in charge of converting our 2007 YFZ450 engine to EFI (its a 5 valve with dual overhead cams). The only problem I've run into is how/where to get a sensor to measure TDC (so a crank or cam sensor). The engine uses stator coils to charge the battery, and I don't think that I can use that in any way for telling microsquirt crank position. Any help as to what type of sensor and its position to tell the ECU when its at TDC would be greatly appreciated. Thanks

Jason

[LycomingHunter]

Hey guys,
Just started school and I'm in charge of converting our 2007 YFZ450 engine to EFI (its a 5 valve with dual overhead cams). The only problem I've run into is how/where to get a sensor to measure TDC (so a crank or cam sensor). The engine uses stator coils to charge the battery, and I don't think that I can use that in any way for telling microsquirt crank position. Any help as to what type of sensor and its position to tell the ECU when its at TDC would be greatly appreciated. Thanks

Jason

[Ben K]

The LTR450 needed a sensor on the cam as well. We ended up having to drill a hole in the cover and bond on a threaded bung on top.

This allowed us to adjust the depth of the threaded sensor for signal recognition by MoTeC.

If Microsquirt doesn't have a quick oscilloscope graph, you will want one for debugging.

Ben

[LycomingHunter]

Thanks for the information. Did you put the MoTeC sensor on the lobe side of the cam? And what type of sensor (not the specific model/part number but VR, optic,...) did you use for the LTR? Thanks

[whiltebeitel]

Hall sensors are often used for sensing crank position with an embedded magnet.

[Mbirt]

Your '07 YFZ450 most likely has a simple trigger arrangement on its flywheel that was unique to the stock ignition unit. For the Honda CRF450X and TRX450ER, it is a long tooth followed by a short tooth. AFAIK, megasquirt won't easily support that. If you machine the stock trigger arrangement from the flywheel, there are a few ways of creating a new trigger arrangement that can be sensed by the stock VR sensor. We machine a ring, press it onto the flywheel, and tack weld it in a few spots.
http://img535.imageshack.us/img535/1127/millingflywheel.jpg

You can weld the individual teeth in place as Penn State did in 2009, but you must be careful not to demagnetize the magnets on the inner surface of the flywheel.

Megasquirt's online write-ups are your best source for analyzing the various trigger arrangement possibilities. I've run our megasquirted FSAE singles on 24-2 wasted spark, 24+1 sequental w/ cam sensor, and 12+1 sequential w/ cam sensor in the past year. I don't want to do too much of your engine controls development for you here, but there are reasons why just about every FSAE team with a thumper runs a cam sensor. You'll find supporters of wasted spark on the megasquirt forums, but most of us either haven't been able to make it work or implemented a cam sensor from the start because MoTeC told us to.

The Honeywell GT101DC is the most common gear-tooth sensor used for cam position. Several teams with Yamaha singles do sense a cam lobe.

[B Lewis @ PE Engine Management]

The stock EFI Yamaha YFZ450 engines do not use a cam sensor. They use a 12-1 tooth crank profile that works great from the factory but you have to get the missing tooth in the right spot for starting. Our new EDGE ECU is plug-and-play for this quad and starting and running is not a problem with this arrangement. It can be done well without adding a cam sensor.

[Justin Norris]

I'm working with Jason on Fuel injecting the YFZ450. We have it running on Microsquirt. The sync is great and the rpm reading is spot on, We are having trouble getting the engine to rev above about 8500 rpm. It runs really smooth up until that point then it starts miss firing and the AFR signal goes crazy. We put an exhaust gas analyzer on it and at about 8500 it is getting a lot of unburned fuel. Has anyone had this issue before and does anyone have any suggestions?

[Drew Price]

Timing too far retarded, too much fuel in that section of the map, or trigger or ignition dropping out and it's not igniting in the first place. That's about all it could be, unless there is some underlying problem with your setup.

[Leibi]

Hi,

we had the same problem a few years ago with our Aprilia. We had no exhaust gas analyzer, but it also had a problem with revving at about 8000 rpm.
At our car the wires coming from the crank sensor were too close to the ignition wiring. So we got problems with electromagnetic compatibility and the ECU miscounted because of the induction of the secondary current of the ignition wiring in the crank signal sensor wiring.

Regards,
Leibi

[revolutionary]

We had similar 'rev limiting' probs with our cbr600 running on microsquirt. We ended up putting a 10kohm resistor in line with crank trigger wire to limit the noise and everything cleared right up. Try starting with a 2kohm if you want to give it a shot.

[Mbirt]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Justin Norris:
I'm working with Jason on Fuel injecting the YFZ450. We have it running on Microsquirt. The sync is great and the rpm reading is spot on, We are having trouble getting the engine to rev above about 8500 rpm. It runs really smooth up until that point then it starts miss firing and the AFR signal goes crazy. We put an exhaust gas analyzer on it and at about 8500 it is getting a lot of unburned fuel. Has anyone had this issue before and does anyone have any suggestions? </div></BLOCKQUOTE>Knowing megasquirt, it's likely sync loss. Make a log of the condition and check it out in megalogviewer. Take note of what the sync loss reason is and then check out the megasquirt/microsquirt forums to see what others have done to fix it. Megasquirt's best feature has to be the community behind it.