probably a stupid question

[boostein]

hey i really appreciate the input. i'll recheck everything and check the resistance on the coil as well.

[boostein]

So this is odd. I set the odd fire TDC's to 0, 90 and the engine started and ran on both cylinders. It ran pretty rough, but this is a lot closer than I've been in the past month.

[boostein]

I have checked the crip with timing light on #1 cylinder several times and I come up with a crip of 400. What's weird is everything I've read and heard says that this engine has a 180 degree crank, which I've confirmed using a degree wheel, yet it does not run with odd fire TDC's of 0, 180 rather 0, 90-120. I'm trying to locate a 10mm piston stop tool so that I can truly verify the TDC of the #2 cylinder and actually make a nice mark on the flywheel. Also, there is a strange mark at 90 degrees ATDC on the flywheel. Does anyone know what this mark represents?

[IDP]

If this is a TRX engine I seem to remember that they are oddfire with a 270 degree offset.
Check with a degree wheel and TDC tool.
I would be inclined to try 0, 270 as oddfire TDC's

[boostein]

well, it's not a TDM or a TRX, as it came out of the 2007 yamaha phazer gt snowmobile. I'll try that though, although I think I've already tried it, but thanks for the reply.

[boostein]

of course, now that the engine actually runs on the odd fire tdc's that it's supposed to have, it only does it if the crip is wrong. with the spark plugs out, the timing light on #1, crip set at 400, test advance set to 0, and cranking, it's right on TDC. the engine will only run now if the crip is between 340 and 380. the closer i set it to 400 the less it actually wants to run. it sounds and revs fine with the crip set to 340, but the timing mark does not show up with the timing light. this is starting to ruin my semester.

[RossB]

You need to check that you are triggering of the correct edges on Ref and Sync. You have been using Ref/sync Mode 12 which means thay you are triggering from the rising edge for Ref and the falling edge for Sync. First of all you need to check the ref sensor signal input with an oscilloscope to check which direction the the voltage is going when it passes straight through 0 volts and select the edge accordingly. (The Ref/Sync mode number determines the edge selection, press "F1" and read the help file on this). Ideally we want the Sync edge to occur as close to half way between 2 Ref teeth so if you look at both signal traces on the oscilloscope and pick the edge which is closest to half way between the ref tooth edges you have selected (the actual trigger point of your Ref is then the voltage passes through 0 volts). You can also check the Sync Rel Position by looking at the View Screen, you should be trying to aim for a position between 30% and 70%. If you change edges you should see this value change and it may also require the CRIP to be adjusted by 36 degrees. I would say that it is likely that you have a problem with one or both of your trigger edges, if either of these are wrong the Sync edge can either move as the slack is taken up in the cam drive system or the Ref trigger point can move as the RPM increases because you are triggering from the wrong edge (the one that isn't passing directly through 0 volts). If the trigger points cross you will have a timing error of 36 degrees which is consistant with what you ar saying is happening.

[jonburf]

Hi boostein.
I have just started working with a genesis 80fi too.
Did you manage to get the angles for the sensors? a rough number would save me a lot of time.
I was really lucky to come accross this post. There is a lot of valuable information.
I have got approximate values for the sensor positions. It would be good to compare.

Hope you can help

Jon Burford

[boostein]

No problem. It may take me a couple days to retrieve the numbers, but I'll do my best and get back to you asap.